mirror of https://github.com/torvalds/linux.git
1646 Commits
| Author | SHA1 | Message | Date |
|---|---|---|---|
Roman Gushchin
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24948e3b7b |
mm: kmem: drop __GFP_NOFAIL when allocating objcg vectors
Objcg vectors attached to slab pages to store slab object ownership information are allocated using gfp flags for the original slab allocation. Depending on slab page order and the size of slab objects, objcg vector can take several pages. If the original allocation was done with the __GFP_NOFAIL flag, it triggered a warning in the page allocation code. Indeed, order > 1 pages should not been allocated with the __GFP_NOFAIL flag. Fix this by simply dropping the __GFP_NOFAIL flag when allocating the objcg vector. It effectively allows to skip the accounting of a single slab object under a heavy memory pressure. An alternative would be to implement the mechanism to fallback to order-0 allocations for accounting metadata, which is also not perfect because it will increase performance penalty and memory footprint of the kernel memory accounting under memory pressure. Link: https://lkml.kernel.org/r/ZUp8ZFGxwmCx4ZFr@P9FQF9L96D.corp.robot.car Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Reported-by: Christoph Lameter <cl@linux.com> Closes: https://lkml.kernel.org/r/6b42243e-f197-600a-5d22-56bd728a5ad8@gentwo.org Acked-by: Shakeel Butt <shakeelb@google.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Muhammad Muzammil
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be16dd764a |
mm: fix multiple typos in multiple files
Link: https://lkml.kernel.org/r/20231023124405.36981-1-m.muzzammilashraf@gmail.com Signed-off-by: Muhammad Muzammil <m.muzzammilashraf@gmail.com> Reviewed-by: Randy Dunlap <rdunlap@infradead.org> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muhammad Muzammil <m.muzzammilashraf@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Roman Gushchin
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e56808fef8 |
mm: kmem: reimplement get_obj_cgroup_from_current()
Reimplement get_obj_cgroup_from_current() using current_obj_cgroup(). get_obj_cgroup_from_current() and current_obj_cgroup() share 80% of the code, so the new implementation is almost trivial. get_obj_cgroup_from_current() is a convenient function used by the bpf subsystem, so there is no reason to get rid of it completely. Link: https://lkml.kernel.org/r/20231019225346.1822282-7-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin (Cruise) <roman.gushchin@linux.dev> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Shakeel Butt <shakeelb@google.com> Cc: David Rientjes <rientjes@google.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Naresh Kamboju <naresh.kamboju@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Roman Gushchin
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e86828e544 |
mm: kmem: scoped objcg protection
Switch to a scope-based protection of the objcg pointer on slab/kmem allocation paths. Instead of using the get_() semantics in the pre-allocation hook and put the reference afterwards, let's rely on the fact that objcg is pinned by the scope. It's possible because: 1) if the objcg is received from the current task struct, the task is keeping a reference to the objcg. 2) if the objcg is received from an active memcg (remote charging), the memcg is pinned by the scope and has a reference to the corresponding objcg. Link: https://lkml.kernel.org/r/20231019225346.1822282-5-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin (Cruise) <roman.gushchin@linux.dev> Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org> Acked-by: Shakeel Butt <shakeelb@google.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Roman Gushchin
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675d6c9b59 |
mm: kmem: make memcg keep a reference to the original objcg
Keep a reference to the original objcg object for the entire life of a memcg structure. This allows to simplify the synchronization on the kernel memory allocation paths: pinning a (live) memcg will also pin the corresponding objcg. The memory overhead of this change is minimal because object cgroups usually outlive their corresponding memory cgroups even without this change, so it's only an additional pointer per memcg. Link: https://lkml.kernel.org/r/20231019225346.1822282-4-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin (Cruise) <roman.gushchin@linux.dev> Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org> Acked-by: Shakeel Butt <shakeelb@google.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Roman Gushchin
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1aacbd3543 |
mm: kmem: add direct objcg pointer to task_struct
To charge a freshly allocated kernel object to a memory cgroup, the kernel
needs to obtain an objcg pointer. Currently it does it indirectly by
obtaining the memcg pointer first and then calling to
__get_obj_cgroup_from_memcg().
Usually tasks spend their entire life belonging to the same object cgroup.
So it makes sense to save the objcg pointer on task_struct directly, so
it can be obtained faster. It requires some work on fork, exit and cgroup
migrate paths, but these paths are way colder.
To avoid any costly synchronization the following rules are applied:
1) A task sets it's objcg pointer itself.
2) If a task is being migrated to another cgroup, the least
significant bit of the objcg pointer is set atomically.
3) On the allocation path the objcg pointer is obtained locklessly
using the READ_ONCE() macro and the least significant bit is
checked. If it's set, the following procedure is used to update
it locklessly:
- task->objcg is zeroed using cmpxcg
- new objcg pointer is obtained
- task->objcg is updated using try_cmpxchg
- operation is repeated if try_cmpxcg fails
It guarantees that no updates will be lost if task migration
is racing against objcg pointer update. It also allows to keep
both read and write paths fully lockless.
Because the task is keeping a reference to the objcg, it can't go away
while the task is alive.
This commit doesn't change the way the remote memcg charging works.
Link: https://lkml.kernel.org/r/20231019225346.1822282-3-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin (Cruise) <roman.gushchin@linux.dev>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Roman Gushchin
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7d0715d0d6 |
mm: kmem: optimize get_obj_cgroup_from_current()
Patch series "mm: improve performance of accounted kernel memory allocations", v5. This patchset improves the performance of accounted kernel memory allocations by ~30% as measured by a micro-benchmark [1]. The benchmark is very straightforward: 1M of 64 bytes-large kmalloc() allocations. Below are results with the disabled kernel memory accounting, the original state and with this patchset applied. | | Kmem disabled | Original | Patched | Delta | |-------------+---------------+----------+---------+--------| | User cgroup | 29764 | 84548 | 59078 | -30.0% | | Root cgroup | 29742 | 48342 | 31501 | -34.8% | As we can see, the patchset removes the majority of the overhead when there is no actual accounting (a task belongs to the root memory cgroup) and almost halves the accounting overhead otherwise. The main idea is to get rid of unnecessary memcg to objcg conversions and switch to a scope-based protection of objcgs, which eliminates extra operations with objcg reference counters under a rcu read lock. More details are provided in individual commit descriptions. This patch (of 5): Manually inline memcg_kmem_bypass() and active_memcg() to speed up get_obj_cgroup_from_current() by avoiding duplicate in_task() checks and active_memcg() readings. Also add a likely() macro to __get_obj_cgroup_from_memcg(): obj_cgroup_tryget() should succeed at almost all times except a very unlikely race with the memcg deletion path. Link: https://lkml.kernel.org/r/20231019225346.1822282-1-roman.gushchin@linux.dev Link: https://lkml.kernel.org/r/20231019225346.1822282-2-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin (Cruise) <roman.gushchin@linux.dev> Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org> Acked-by: Shakeel Butt <shakeelb@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Nhat Pham
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8cba9576df |
hugetlb: memcg: account hugetlb-backed memory in memory controller
Currently, hugetlb memory usage is not acounted for in the memory
controller, which could lead to memory overprotection for cgroups with
hugetlb-backed memory. This has been observed in our production system.
For instance, here is one of our usecases: suppose there are two 32G
containers. The machine is booted with hugetlb_cma=6G, and each container
may or may not use up to 3 gigantic page, depending on the workload within
it. The rest is anon, cache, slab, etc. We can set the hugetlb cgroup
limit of each cgroup to 3G to enforce hugetlb fairness. But it is very
difficult to configure memory.max to keep overall consumption, including
anon, cache, slab etc. fair.
What we have had to resort to is to constantly poll hugetlb usage and
readjust memory.max. Similar procedure is done to other memory limits
(memory.low for e.g). However, this is rather cumbersome and buggy.
Furthermore, when there is a delay in memory limits correction, (for e.g
when hugetlb usage changes within consecutive runs of the userspace
agent), the system could be in an over/underprotected state.
This patch rectifies this issue by charging the memcg when the hugetlb
folio is utilized, and uncharging when the folio is freed (analogous to
the hugetlb controller). Note that we do not charge when the folio is
allocated to the hugetlb pool, because at this point it is not owned by
any memcg.
Some caveats to consider:
* This feature is only available on cgroup v2.
* There is no hugetlb pool management involved in the memory
controller. As stated above, hugetlb folios are only charged towards
the memory controller when it is used. Host overcommit management
has to consider it when configuring hard limits.
* Failure to charge towards the memcg results in SIGBUS. This could
happen even if the hugetlb pool still has pages (but the cgroup
limit is hit and reclaim attempt fails).
* When this feature is enabled, hugetlb pages contribute to memory
reclaim protection. low, min limits tuning must take into account
hugetlb memory.
* Hugetlb pages utilized while this option is not selected will not
be tracked by the memory controller (even if cgroup v2 is remounted
later on).
Link: https://lkml.kernel.org/r/20231006184629.155543-4-nphamcs@gmail.com
Signed-off-by: Nhat Pham <nphamcs@gmail.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Frank van der Linden <fvdl@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Rik van Riel <riel@surriel.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Tejun heo <tj@kernel.org>
Cc: Yosry Ahmed <yosryahmed@google.com>
Cc: Zefan Li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Nhat Pham
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85ce2c517a |
memcontrol: only transfer the memcg data for migration
For most migration use cases, only transfer the memcg data from the old folio to the new folio, and clear the old folio's memcg data. No charging and uncharging will be done. This shaves off some work on the migration path, and avoids the temporary double charging of a folio during its migration. The only exception is replace_page_cache_folio(), which will use the old mem_cgroup_migrate() (now renamed to mem_cgroup_replace_folio). In that context, the isolation of the old page isn't quite as thorough as with migration, so we cannot use our new implementation directly. This patch is the result of the following discussion on the new hugetlb memcg accounting behavior: https://lore.kernel.org/lkml/20231003171329.GB314430@monkey/ Link: https://lkml.kernel.org/r/20231006184629.155543-3-nphamcs@gmail.com Signed-off-by: Nhat Pham <nphamcs@gmail.com> Suggested-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Frank van der Linden <fvdl@google.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Rik van Riel <riel@surriel.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Shakeel Butt <shakeelb@google.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Tejun heo <tj@kernel.org> Cc: Yosry Ahmed <yosryahmed@google.com> Cc: Zefan Li <lizefan.x@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Nhat Pham
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4b569387c0 |
memcontrol: add helpers for hugetlb memcg accounting
Patch series "hugetlb memcg accounting", v4. Currently, hugetlb memory usage is not acounted for in the memory controller, which could lead to memory overprotection for cgroups with hugetlb-backed memory. This has been observed in our production system. For instance, here is one of our usecases: suppose there are two 32G containers. The machine is booted with hugetlb_cma=6G, and each container may or may not use up to 3 gigantic page, depending on the workload within it. The rest is anon, cache, slab, etc. We can set the hugetlb cgroup limit of each cgroup to 3G to enforce hugetlb fairness. But it is very difficult to configure memory.max to keep overall consumption, including anon, cache, slab etcetera fair. What we have had to resort to is to constantly poll hugetlb usage and readjust memory.max. Similar procedure is done to other memory limits (memory.low for e.g). However, this is rather cumbersome and buggy. Furthermore, when there is a delay in memory limits correction, (for e.g when hugetlb usage changes within consecutive runs of the userspace agent), the system could be in an over/underprotected state. This patch series rectifies this issue by charging the memcg when the hugetlb folio is allocated, and uncharging when the folio is freed. In addition, a new selftest is added to demonstrate and verify this new behavior. This patch (of 4): This patch exposes charge committing and cancelling as parts of the memory controller interface. These functionalities are useful when the try_charge() and commit_charge() stages have to be separated by other actions in between (which can fail). One such example is the new hugetlb accounting behavior in the following patch. The patch also adds a helper function to obtain a reference to the current task's memcg. Link: https://lkml.kernel.org/r/20231006184629.155543-1-nphamcs@gmail.com Link: https://lkml.kernel.org/r/20231006184629.155543-2-nphamcs@gmail.com Signed-off-by: Nhat Pham <nphamcs@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Frank van der Linden <fvdl@google.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Rik van Riel <riel@surriel.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Shakeel Butt <shakeelb@google.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Tejun heo <tj@kernel.org> Cc: Yosry Ahmed <yosryahmed@google.com> Cc: Zefan Li <lizefan.x@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Yosry Ahmed
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7bd5bc3ce9 |
mm: memcg: normalize the value passed into memcg_rstat_updated()
memcg_rstat_updated() uses the value of the state update to keep track of
the magnitude of pending updates, so that we only do a stats flush when
it's worth the work. Most values passed into memcg_rstat_updated() are in
pages, however, a few of them are actually in bytes or KBs.
To put this into perspective, a 512 byte slab allocation today would look
the same as allocating 512 pages. This may result in premature flushes,
which means unnecessary work and latency.
Normalize all the state values passed into memcg_rstat_updated() to pages.
Round up non-zero sub-page to 1 page, because memcg_rstat_updated()
ignores 0 page updates.
Link: https://lkml.kernel.org/r/20230922175741.635002-3-yosryahmed@google.com
Fixes:
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Yosry Ahmed
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ff841a06c8 |
mm: memcg: refactor page state unit helpers
Patch series "mm: memcg: fix tracking of pending stats updates values", v2. While working on adjacent code [1], I realized that the values passed into memcg_rstat_updated() to keep track of the magnitude of pending updates is consistent. It is mostly in pages, but sometimes it can be in bytes or KBs. Fix that. Patch 1 reworks memcg_page_state_unit() so that we can reuse it in patch 2 to check and normalize the units of state updates. [1]https://lore.kernel.org/lkml/20230921081057.3440885-1-yosryahmed@google.com/ This patch (of 2): memcg_page_state_unit() is currently used to identify the unit of a memcg state item so that all stats in memory.stat are in bytes. However, it lies about the units of WORKINGSET_* stats. These stats actually represent pages, but we present them to userspace as a scalar number of events. In retrospect, maybe those stats should have been memcg "events" rather than memcg "state". In preparation for using memcg_page_state_unit() for other purposes that need to know the truthful units of different stat items, break it down into two helpers: - memcg_page_state_unit() retuns the actual unit of the item. - memcg_page_state_output_unit() returns the unit used for output. Use the latter instead of the former in memcg_page_state_output() and lruvec_page_state_output(). While we are at it, let's show cgroup v1 some love and add memcg_page_state_local_output() for consistency. No functional change intended. Link: https://lkml.kernel.org/r/20230922175741.635002-1-yosryahmed@google.com Link: https://lkml.kernel.org/r/20230922175741.635002-2-yosryahmed@google.com Signed-off-by: Yosry Ahmed <yosryahmed@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michal Koutný <mkoutny@suse.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Shakeel Butt <shakeelb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Liu Shixin
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840ea53a8d |
memcg: remove unused do_memsw_account in memcg1_stat_format
Since commit b25806dcd3d5("mm: memcontrol: deprecate swapaccounting=0
mode") do_memsw_account() is synonymous with
!cgroup_subsys_on_dfl(memory_cgrp_subsys), It always equals true in
memcg1_stat_format(). Remove the unused code.
Link: https://lkml.kernel.org/r/20230915105845.3199656-3-liushixin2@huawei.com
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Suggested-by: Michal Koutný <mkoutny@suse.com>
Reviewed-by: Yosry Ahmed <yosryahmed@google.com>
Acked-by: Tejun heo <tj@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Zefan Li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Liu Shixin
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72a14e821c |
memcg: expose swapcache stat for memcg v1
Patch series "Expose swapcache stat for memcg v1", v2.
Since commit
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Xin Hao
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811244a501 |
mm: memcg: add THP swap out info for anonymous reclaim
At present, we support per-memcg reclaim strategy, however we do not know the number of transparent huge pages being reclaimed, as we know the transparent huge pages need to be splited before reclaim them, and they will bring some performance bottleneck effect. for example, when two memcg (A & B) are doing reclaim for anonymous pages at same time, and 'A' memcg is reclaiming a large number of transparent huge pages, we can better analyze that the performance bottleneck will be caused by 'A' memcg. therefore, in order to better analyze such problems, there add THP swap out info for per-memcg. [akpm@linux-foundation.orgL fix swap_writepage_fs(), per Johannes] Link: https://lkml.kernel.org/r/20230913213343.GB48476@cmpxchg.org Link: https://lkml.kernel.org/r/20230913164938.16918-1-vernhao@tencent.com Signed-off-by: Xin Hao <vernhao@tencent.com> Suggested-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Shakeel Butt <shakeelb@google.com> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Michal Hocko
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4597648fdd |
mm, memcg: reconsider kmem.limit_in_bytes deprecation
This reverts commits |
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Johannes Weiner
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9ea9cb00a8 |
mm: memcontrol: fix GFP_NOFS recursion in memory.high enforcement
Breno and Josef report a deadlock scenario from cgroup reclaim re-entering the filesystem: [ 361.546690] ====================================================== [ 361.559210] WARNING: possible circular locking dependency detected [ 361.571703] 6.5.0-0_fbk700_debug_rc0_kbuilder_13159_gbf787a128001 #1 Tainted: G S E [ 361.589704] ------------------------------------------------------ [ 361.602277] find/9315 is trying to acquire lock: [ 361.611625] ffff88837ba140c0 (&delayed_node->mutex){+.+.}-{4:4}, at: __btrfs_release_delayed_node+0x68/0x4f0 [ 361.631437] [ 361.631437] but task is already holding lock: [ 361.643243] ffff8881765b8678 (btrfs-tree-01){++++}-{4:4}, at: btrfs_tree_read_lock+0x1e/0x40 [ 362.904457] mutex_lock_nested+0x1c/0x30 [ 362.912414] __btrfs_release_delayed_node+0x68/0x4f0 [ 362.922460] btrfs_evict_inode+0x301/0x770 [ 362.982726] evict+0x17c/0x380 [ 362.988944] prune_icache_sb+0x100/0x1d0 [ 363.005559] super_cache_scan+0x1f8/0x260 [ 363.013695] do_shrink_slab+0x2a2/0x540 [ 363.021489] shrink_slab_memcg+0x237/0x3d0 [ 363.050606] shrink_slab+0xa7/0x240 [ 363.083382] shrink_node_memcgs+0x262/0x3b0 [ 363.091870] shrink_node+0x1a4/0x720 [ 363.099150] shrink_zones+0x1f6/0x5d0 [ 363.148798] do_try_to_free_pages+0x19b/0x5e0 [ 363.157633] try_to_free_mem_cgroup_pages+0x266/0x370 [ 363.190575] reclaim_high+0x16f/0x1f0 [ 363.208409] mem_cgroup_handle_over_high+0x10b/0x270 [ 363.246678] try_charge_memcg+0xaf2/0xc70 [ 363.304151] charge_memcg+0xf0/0x350 [ 363.320070] __mem_cgroup_charge+0x28/0x40 [ 363.328371] __filemap_add_folio+0x870/0xd50 [ 363.371303] filemap_add_folio+0xdd/0x310 [ 363.399696] __filemap_get_folio+0x2fc/0x7d0 [ 363.419086] pagecache_get_page+0xe/0x30 [ 363.427048] alloc_extent_buffer+0x1cd/0x6a0 [ 363.435704] read_tree_block+0x43/0xc0 [ 363.443316] read_block_for_search+0x361/0x510 [ 363.466690] btrfs_search_slot+0xc8c/0x1520 This is caused by the mem_cgroup_handle_over_high() not respecting the gfp_mask of the allocation context. We used to only call this function on resume to userspace, where no locks were held. But |
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Johannes Weiner
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6f0df8e16e |
memcontrol: ensure memcg acquired by id is properly set up
In the eviction recency check, we attempt to retrieve the memcg to which
the folio belonged when it was evicted, by the memcg id stored in the
shadow entry. However, there is a chance that the retrieved memcg is not
the original memcg that has been killed, but a new one which happens to
have the same id.
This is a somewhat unfortunate, but acceptable and rare inaccuracy in the
heuristics. However, if we retrieve this new memcg between its allocation
and when it is properly attached to the memcg hierarchy, we could run into
the following NULL pointer exception during the memcg hierarchy traversal
done in mem_cgroup_get_nr_swap_pages():
[ 155757.793456] BUG: kernel NULL pointer dereference, address: 00000000000000c0
[ 155757.807568] #PF: supervisor read access in kernel mode
[ 155757.818024] #PF: error_code(0x0000) - not-present page
[ 155757.828482] PGD 401f77067 P4D 401f77067 PUD 401f76067 PMD 0
[ 155757.839985] Oops: 0000 [#1] SMP
[ 155757.887870] RIP: 0010:mem_cgroup_get_nr_swap_pages+0x3d/0xb0
[ 155757.899377] Code: 29 19 4a 02 48 39 f9 74 63 48 8b 97 c0 00 00 00 48 8b b7 58 02 00 00 48 2b b7 c0 01 00 00 48 39 f0 48 0f 4d c6 48 39 d1 74 42 <48> 8b b2 c0 00 00 00 48 8b ba 58 02 00 00 48 2b ba c0 01 00 00 48
[ 155757.937125] RSP: 0018:ffffc9002ecdfbc8 EFLAGS: 00010286
[ 155757.947755] RAX: 00000000003a3b1c RBX: 000007ffffffffff RCX: ffff888280183000
[ 155757.962202] RDX: 0000000000000000 RSI: 0007ffffffffffff RDI: ffff888bbc2d1000
[ 155757.976648] RBP: 0000000000000001 R08: 000000000000000b R09: ffff888ad9cedba0
[ 155757.991094] R10: ffffea0039c07900 R11: 0000000000000010 R12: ffff888b23a7b000
[ 155758.005540] R13: 0000000000000000 R14: ffff888bbc2d1000 R15: 000007ffffc71354
[ 155758.019991] FS: 00007f6234c68640(0000) GS:ffff88903f9c0000(0000) knlGS:0000000000000000
[ 155758.036356] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 155758.048023] CR2: 00000000000000c0 CR3: 0000000a83eb8004 CR4: 00000000007706e0
[ 155758.062473] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 155758.076924] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 155758.091376] PKRU: 55555554
[ 155758.096957] Call Trace:
[ 155758.102016] <TASK>
[ 155758.106502] ? __die+0x78/0xc0
[ 155758.112793] ? page_fault_oops+0x286/0x380
[ 155758.121175] ? exc_page_fault+0x5d/0x110
[ 155758.129209] ? asm_exc_page_fault+0x22/0x30
[ 155758.137763] ? mem_cgroup_get_nr_swap_pages+0x3d/0xb0
[ 155758.148060] workingset_test_recent+0xda/0x1b0
[ 155758.157133] workingset_refault+0xca/0x1e0
[ 155758.165508] filemap_add_folio+0x4d/0x70
[ 155758.173538] page_cache_ra_unbounded+0xed/0x190
[ 155758.182919] page_cache_sync_ra+0xd6/0x1e0
[ 155758.191738] filemap_read+0x68d/0xdf0
[ 155758.199495] ? mlx5e_napi_poll+0x123/0x940
[ 155758.207981] ? __napi_schedule+0x55/0x90
[ 155758.216095] __x64_sys_pread64+0x1d6/0x2c0
[ 155758.224601] do_syscall_64+0x3d/0x80
[ 155758.232058] entry_SYSCALL_64_after_hwframe+0x46/0xb0
[ 155758.242473] RIP: 0033:0x7f62c29153b5
[ 155758.249938] Code: e8 48 89 75 f0 89 7d f8 48 89 4d e0 e8 b4 e6 f7 ff 41 89 c0 4c 8b 55 e0 48 8b 55 e8 48 8b 75 f0 8b 7d f8 b8 11 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 33 44 89 c7 48 89 45 f8 e8 e7 e6 f7 ff 48 8b
[ 155758.288005] RSP: 002b:00007f6234c5ffd0 EFLAGS: 00000293 ORIG_RAX: 0000000000000011
[ 155758.303474] RAX: ffffffffffffffda RBX: 00007f628c4e70c0 RCX: 00007f62c29153b5
[ 155758.318075] RDX: 000000000003c041 RSI: 00007f61d2986000 RDI: 0000000000000076
[ 155758.332678] RBP: 00007f6234c5fff0 R08: 0000000000000000 R09: 0000000064d5230c
[ 155758.347452] R10: 000000000027d450 R11: 0000000000000293 R12: 000000000003c041
[ 155758.362044] R13: 00007f61d2986000 R14: 00007f629e11b060 R15: 000000000027d450
[ 155758.376661] </TASK>
This patch fixes the issue by moving the memcg's id publication from the
alloc stage to online stage, ensuring that any memcg acquired via id must
be connected to the memcg tree.
Link: https://lkml.kernel.org/r/20230823225430.166925-1-nphamcs@gmail.com
Fixes:
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|
Matthew Wilcox (Oracle)
|
853f62a304 |
mm: fix get_mctgt_type() kernel-doc
Convert the return values to an ReST list and tidy up the wording while I'm touching it. [akpm@linux-foundation.org: changes suggested by Randy] [willy@infradead.org: another change suggested by Randy] Link: https://lkml.kernel.org/r/ZOUZtZizeQG7PcsM@casper.infradead.org Link: https://lkml.kernel.org/r/20230818200630.2719595-3-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Mike Rapoport (IBM) <rppt@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
|
Lu Jialin
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14a405c3a9 |
memcg: remove duplication detection for mem_cgroup_uncharge_swap
__mem_cgroup_uncharge_swap is only called in mem_cgroup_uncharge_swap, if mem cgroup is disabled, __mem_cgroup_uncharge_swap cannot be called. Therefore, there is no need to judge whether mem_cgroup is disabled or not. Link: https://lkml.kernel.org/r/20230819081302.1217098-1-lujialin4@huawei.com Signed-off-by: Lu Jialin <lujialin4@huawei.com> Acked-by: Shakeel Butt <shakeelb@google.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Yosry Ahmed
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f82e6bf9bb |
mm: memcg: use rstat for non-hierarchical stats
Currently, memcg uses rstat to maintain aggregated hierarchical stats. Counters are maintained for hierarchical stats at each memcg. Rstat tracks which cgroups have updates on which cpus to keep those counters fresh on the read-side. Non-hierarchical stats are currently not covered by rstat. Their per-cpu counters are summed up on every read, which is expensive. The original implementation did the same. At some point before rstat, non-hierarchical aggregated counters were introduced by commit |
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Matthew Wilcox (Oracle)
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6199277baf |
mm: remove folio_test_transhuge()
This function is misleading; people think it means "Is this a THP", when all it actually does is check whether this is a large folio. Remove it; the one remaining user should have been checking to see whether the folio is PMD sized or not. Link: https://lkml.kernel.org/r/20230816151201.3655946-12-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: David Hildenbrand <david@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Yanteng Si <siyanteng@loongson.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Andrew Morton
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5994eabf3b | merge mm-hotfixes-stable into mm-stable to pick up depended-upon changes | |
ZhangPeng
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61f2973801 |
mm: remove redundant K() macro definition
Patch series "cleanup with helper macro K()".
Use helper macro K() to improve code readability. No functional
modification involved. Remove redundant K() macro definition.
This patch (of 7):
Since commit
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Miaohe Lin
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3a1060c261 |
mm/memcg: fix wrong function name above obj_cgroup_charge_zswap()
The correct function name is obj_cgroup_may_zswap(). Correct the comment. Link: https://lkml.kernel.org/r/20230803120021.762279-1-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Efly Young
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0388536ac2 |
mm:vmscan: fix inaccurate reclaim during proactive reclaim
Before commit
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Matthew Wilcox (Oracle)
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074e3e262a |
memcg: convert get_obj_cgroup_from_page to get_obj_cgroup_from_folio
As the one caller now has a folio, pass it in and use it. Removes three calls to compound_head(). Link: https://lkml.kernel.org/r/20230715042343.434588-4-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Vitaly Wool <vitaly.wool@konsulko.com> Cc: Yosry Ahmed <yosryahmed@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Suren Baghdasaryan
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49b0638502 |
mm: enable page walking API to lock vmas during the walk
walk_page_range() and friends often operate under write-locked mmap_lock. With introduction of vma locks, the vmas have to be locked as well during such walks to prevent concurrent page faults in these areas. Add an additional member to mm_walk_ops to indicate locking requirements for the walk. The change ensures that page walks which prevent concurrent page faults by write-locking mmap_lock, operate correctly after introduction of per-vma locks. With per-vma locks page faults can be handled under vma lock without taking mmap_lock at all, so write locking mmap_lock would not stop them. The change ensures vmas are properly locked during such walks. A sample issue this solves is do_mbind() performing queue_pages_range() to queue pages for migration. Without this change a concurrent page can be faulted into the area and be left out of migration. Link: https://lkml.kernel.org/r/20230804152724.3090321-2-surenb@google.com Signed-off-by: Suren Baghdasaryan <surenb@google.com> Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org> Suggested-by: Jann Horn <jannh@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Laurent Dufour <ldufour@linux.ibm.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Michel Lespinasse <michel@lespinasse.org> Cc: Peter Xu <peterx@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Miaohe Lin
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58f341f772 |
mm/memcg: minor cleanup for mc_handle_present_pte()
When pagetable lock is held, the page will always be page_mapped(). So remove unneeded page_mapped() check. Also the page can't be freed from under us in this case. So use get_page() to get extra page reference to simplify the code. No functional change intended. Link: https://lkml.kernel.org/r/20230717113644.3026478-1-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Shakeel Butt <shakeelb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Miaohe Lin
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f4d005af5b |
mm/memcg: fix obsolete comment above MEM_CGROUP_MAX_RECLAIM_LOOPS
Since commit
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Miaohe Lin
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60b1e24ce8 |
mm/memcg: minor cleanup for MEM_CGROUP_ID_MAX
MEM_CGROUP_ID_MAX is only used when CONFIG_MEMCG is configured. So remove unneeded !CONFIG_MEMCG variant. Also it's only used in mem_cgroup_alloc(), so move it from memcontrol.h to memcontrol.c. And further define it as: #define MEM_CGROUP_ID_MAX ((1UL << MEM_CGROUP_ID_SHIFT) - 1) so if someone changes MEM_CGROUP_ID_SHIFT in the future, then MEM_CGROUP_ID_MAX will be updated accordingly, as suggested by Muchun. Link: https://lkml.kernel.org/r/20230708023304.1184111-1-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Shakeel Butt <shakeelb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Michal Hocko
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86327e8eb9 |
memcg: drop kmem.limit_in_bytes
kmem.limit_in_bytes (v1 way to limit kernel memory usage) has been deprecated since |
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Haifeng Xu
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91f0dccef1 |
mm/memcontrol: do not tweak node in mem_cgroup_init()
mem_cgroup_init() request for allocations from each possible node, and
it's used to be a problem because NODE_DATA is not allocated for offline
node. Things have already changed since commit
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ZhangPeng
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025b7799b3 |
mm/memcg: remove return value of mem_cgroup_scan_tasks()
No user checks the return value of mem_cgroup_scan_tasks(). Make the return value void. Link: https://lkml.kernel.org/r/20230616063030.977586-1-zhangpeng362@huawei.com Signed-off-by: ZhangPeng <zhangpeng362@huawei.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nanyong Sun <sunnanyong@huawei.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Shakeel Butt <shakeelb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Kefeng Wang
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6c77b607ee |
mm: kill lock|unlock_page_memcg()
Since commit
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Ryan Roberts
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c33c794828 |
mm: ptep_get() conversion
Convert all instances of direct pte_t* dereferencing to instead use ptep_get() helper. This means that by default, the accesses change from a C dereference to a READ_ONCE(). This is technically the correct thing to do since where pgtables are modified by HW (for access/dirty) they are volatile and therefore we should always ensure READ_ONCE() semantics. But more importantly, by always using the helper, it can be overridden by the architecture to fully encapsulate the contents of the pte. Arch code is deliberately not converted, as the arch code knows best. It is intended that arch code (arm64) will override the default with its own implementation that can (e.g.) hide certain bits from the core code, or determine young/dirty status by mixing in state from another source. Conversion was done using Coccinelle: ---- // $ make coccicheck \ // COCCI=ptepget.cocci \ // SPFLAGS="--include-headers" \ // MODE=patch virtual patch @ depends on patch @ pte_t *v; @@ - *v + ptep_get(v) ---- Then reviewed and hand-edited to avoid multiple unnecessary calls to ptep_get(), instead opting to store the result of a single call in a variable, where it is correct to do so. This aims to negate any cost of READ_ONCE() and will benefit arch-overrides that may be more complex. Included is a fix for an issue in an earlier version of this patch that was pointed out by kernel test robot. The issue arose because config MMU=n elides definition of the ptep helper functions, including ptep_get(). HUGETLB_PAGE=n configs still define a simple huge_ptep_clear_flush() for linking purposes, which dereferences the ptep. So when both configs are disabled, this caused a build error because ptep_get() is not defined. Fix by continuing to do a direct dereference when MMU=n. This is safe because for this config the arch code cannot be trying to virtualize the ptes because none of the ptep helpers are defined. Link: https://lkml.kernel.org/r/20230612151545.3317766-4-ryan.roberts@arm.com Reported-by: kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/oe-kbuild-all/202305120142.yXsNEo6H-lkp@intel.com/ Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Potapenko <glider@google.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Dave Airlie <airlied@gmail.com> Cc: Dimitri Sivanich <dimitri.sivanich@hpe.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ian Rogers <irogers@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: SeongJae Park <sj@kernel.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Hugh Dickins
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04dee9e85c |
mm/various: give up if pte_offset_map[_lock]() fails
Following the examples of nearby code, various functions can just give up if pte_offset_map() or pte_offset_map_lock() fails. And there's no need for a preliminary pmd_trans_unstable() or other such check, since such cases are now safely handled inside. Link: https://lkml.kernel.org/r/7b9bd85d-1652-cbf2-159d-f503b45e5b@google.com Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Christoph Hellwig <hch@infradead.org> Cc: David Hildenbrand <david@redhat.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Peter Xu <peterx@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: SeongJae Park <sj@kernel.org> Cc: Song Liu <song@kernel.org> Cc: Steven Price <steven.price@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Will Deacon <will@kernel.org> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Zack Rusin <zackr@vmware.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Miaohe Lin
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396faf8898 |
memcg: use helper macro FLUSH_TIME
Use helper macro FLUSH_TIME to indicate the flush time to improve the readability a bit. No functional change intended. Link: https://lkml.kernel.org/r/20230603072116.1101690-1-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Acked-by: Shakeel Butt <shakeelb@google.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: David Hildenbrand <david@redhat.com> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Lars R. Damerow
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e0e0b4126c |
mm/memcontrol: export memcg.swap watermark via sysfs for v2 memcg
This patch is similar to commit
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T.J. Alumbaugh
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5c7e7a0d79 |
mm: multi-gen LRU: cleanup lru_gen_soft_reclaim()
lru_gen_soft_reclaim() gets the lruvec from the memcg and node ID to keep a cleaner interface on the caller side. Link: https://lkml.kernel.org/r/20230522112058.2965866-2-talumbau@google.com Signed-off-by: T.J. Alumbaugh <talumbau@google.com> Reviewed-by: Yuanchu Xie <yuanchu@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Haifeng Xu
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08e0f49e99 |
mm/memcontrol: fix typo in comment
Replace 'then' with 'than'. Link: https://lkml.kernel.org/r/20230522095233.4246-1-haifeng.xu@shopee.com Signed-off-by: Haifeng Xu <haifeng.xu@shopee.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Shakeel Butt <shakeelb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Haifeng Xu
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18b1d18bc2 |
memcg, oom: remove explicit wakeup in mem_cgroup_oom_synchronize()
Before commit
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Haifeng Xu
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857f21397f |
memcg, oom: remove unnecessary check in mem_cgroup_oom_synchronize()
mem_cgroup_oom_synchronize() is only used when the memcg oom handling is
handed over to the edge of the #PF path. Since commit
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Yosry Ahmed
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35822fdae3 |
memcg: remove mem_cgroup_flush_stats_atomic()
Previous patches removed all callers of mem_cgroup_flush_stats_atomic(). Remove the function and simplify the code. Link: https://lkml.kernel.org/r/20230421174020.2994750-5-yosryahmed@google.com Signed-off-by: Yosry Ahmed <yosryahmed@google.com> Acked-by: Shakeel Butt <shakeelb@google.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> Cc: Jan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@kernel.dk> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michal Koutný <mkoutny@suse.com> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Yosry Ahmed
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f82a7a86db |
memcg: calculate root usage from global state
Currently, we approximate the root usage by adding the memcg stats for anon, file, and conditionally swap (for memsw). To read the memcg stats we need to invoke an rstat flush. rstat flushes can be expensive, they scale with the number of cpus and cgroups on the system. mem_cgroup_usage() is called by memcg_events()->mem_cgroup_threshold() with irqs disabled, so such an expensive operation with irqs disabled can cause problems. Instead, approximate the root usage from global state. This is not 100% accurate, but the root usage has always been ill-defined anyway. Link: https://lkml.kernel.org/r/20230421174020.2994750-4-yosryahmed@google.com Signed-off-by: Yosry Ahmed <yosryahmed@google.com> Reviewed-by: Michal Koutný <mkoutny@suse.com> Acked-by: Shakeel Butt <shakeelb@google.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> Cc: Jan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@kernel.dk> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Yosry Ahmed
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190409caaf |
memcg: flush stats non-atomically in mem_cgroup_wb_stats()
The previous patch moved the wb_over_bg_thresh()->mem_cgroup_wb_stats() code path in wb_writeback() outside the lock section. We no longer need to flush the stats atomically. Flush the stats non-atomically. Link: https://lkml.kernel.org/r/20230421174020.2994750-3-yosryahmed@google.com Signed-off-by: Yosry Ahmed <yosryahmed@google.com> Reviewed-by: Michal Koutný <mkoutny@suse.com> Acked-by: Shakeel Butt <shakeelb@google.com> Acked-by: Tejun Heo <tj@kernel.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> Cc: Jan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@kernel.dk> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Yosry Ahmed
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dddb44ffa0 |
memcg: dump memory.stat during cgroup OOM for v1
Patch series "memcg: OOM log improvements", v2. This short patch series brings back some cgroup v1 stats in OOM logs that were unnecessarily changed before. It also makes memcg OOM logs less reliant on printk() internals. This patch (of 2): Commit |
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Yosry Ahmed
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5b42360c73 |
memcg: use seq_buf_do_printk() with mem_cgroup_print_oom_meminfo()
Currently, we format all the memcg stats into a buffer in mem_cgroup_print_oom_meminfo() and use pr_info() to dump it to the logs. However, this buffer is large in size. Although it is currently working as intended, ther is a dependency between the memcg stats buffer and the printk record size limit. If we add more stats in the future and the buffer becomes larger than the printk record size limit, or if the prink record size limit is reduced, the logs may be truncated. It is safer to use seq_buf_do_printk(), which will automatically break up the buffer at line breaks and issue small printk() calls. Refactor the code to move the seq_buf from memory_stat_format() to its callers, and use seq_buf_do_printk() to print the seq_buf in mem_cgroup_print_oom_meminfo(). Link: https://lkml.kernel.org/r/20230428132406.2540811-2-yosryahmed@google.com Signed-off-by: Yosry Ahmed <yosryahmed@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Acked-by: Shakeel Butt <shakeelb@google.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Roman Gushchin
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f785a8f21a |
mm: memcg: use READ_ONCE()/WRITE_ONCE() to access stock->cached
A memcg pointer in the percpu stock can be accessed by drain_all_stock() from another cpu in a lockless way. In theory it might lead to an issue, similar to the one which has been discovered with stock->cached_objcg, where the pointer was zeroed between the check for being NULL and dereferencing. In this case the issue is unlikely a real problem, but to make it bulletproof and similar to stock->cached_objcg, let's annotate all accesses to stock->cached with READ_ONCE()/WTRITE_ONCE(). Link: https://lkml.kernel.org/r/20230502160839.361544-2-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: Shakeel Butt <shakeelb@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Yosry Ahmed <yosryahmed@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Roman Gushchin
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3b8abb3239 |
mm: kmem: fix a NULL pointer dereference in obj_stock_flush_required()
KCSAN found an issue in obj_stock_flush_required():
stock->cached_objcg can be reset between the check and dereference:
==================================================================
BUG: KCSAN: data-race in drain_all_stock / drain_obj_stock
write to 0xffff888237c2a2f8 of 8 bytes by task 19625 on cpu 0:
drain_obj_stock+0x408/0x4e0 mm/memcontrol.c:3306
refill_obj_stock+0x9c/0x1e0 mm/memcontrol.c:3340
obj_cgroup_uncharge+0xe/0x10 mm/memcontrol.c:3408
memcg_slab_free_hook mm/slab.h:587 [inline]
__cache_free mm/slab.c:3373 [inline]
__do_kmem_cache_free mm/slab.c:3577 [inline]
kmem_cache_free+0x105/0x280 mm/slab.c:3602
__d_free fs/dcache.c:298 [inline]
dentry_free fs/dcache.c:375 [inline]
__dentry_kill+0x422/0x4a0 fs/dcache.c:621
dentry_kill+0x8d/0x1e0
dput+0x118/0x1f0 fs/dcache.c:913
__fput+0x3bf/0x570 fs/file_table.c:329
____fput+0x15/0x20 fs/file_table.c:349
task_work_run+0x123/0x160 kernel/task_work.c:179
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
exit_to_user_mode_loop+0xcf/0xe0 kernel/entry/common.c:171
exit_to_user_mode_prepare+0x6a/0xa0 kernel/entry/common.c:203
__syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
syscall_exit_to_user_mode+0x26/0x140 kernel/entry/common.c:296
do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x63/0xcd
read to 0xffff888237c2a2f8 of 8 bytes by task 19632 on cpu 1:
obj_stock_flush_required mm/memcontrol.c:3319 [inline]
drain_all_stock+0x174/0x2a0 mm/memcontrol.c:2361
try_charge_memcg+0x6d0/0xd10 mm/memcontrol.c:2703
try_charge mm/memcontrol.c:2837 [inline]
mem_cgroup_charge_skmem+0x51/0x140 mm/memcontrol.c:7290
sock_reserve_memory+0xb1/0x390 net/core/sock.c:1025
sk_setsockopt+0x800/0x1e70 net/core/sock.c:1525
udp_lib_setsockopt+0x99/0x6c0 net/ipv4/udp.c:2692
udp_setsockopt+0x73/0xa0 net/ipv4/udp.c:2817
sock_common_setsockopt+0x61/0x70 net/core/sock.c:3668
__sys_setsockopt+0x1c3/0x230 net/socket.c:2271
__do_sys_setsockopt net/socket.c:2282 [inline]
__se_sys_setsockopt net/socket.c:2279 [inline]
__x64_sys_setsockopt+0x66/0x80 net/socket.c:2279
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
value changed: 0xffff8881382d52c0 -> 0xffff888138893740
Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 19632 Comm: syz-executor.0 Not tainted 6.3.0-rc2-syzkaller-00387-g534293368afa #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
Fix it by using READ_ONCE()/WRITE_ONCE() for all accesses to
stock->cached_objcg.
Link: https://lkml.kernel.org/r/20230502160839.361544-1-roman.gushchin@linux.dev
Fixes:
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Yosry Ahmed
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ec342603e6 |
memcg: page_cgroup_ino() get memcg from the page's folio
In a kernel with added WARN_ON_ONCE(PageTail) in page_memcg_check(), we observed a warning from page_cgroup_ino() when reading /proc/kpagecgroup. This warning was added to catch fragile reads of a page memcg. Make page_cgroup_ino() get memcg from the page's folio using folio_memcg_check(): that gives it the correct memcg for each page of a folio, so is the right fix. Note that page_folio() is racy, the page's folio can change from under us, but the entire function is racy and documented as such. I dithered between the right fix and the safer "fix": it's unlikely but conceivable that some userspace has learnt that /proc/kpagecgroup gives no memcg on tail pages, and compensates for that in some (racy) way: so continuing to give no memcg on tails, without warning, might be safer. But hwpoison_filter_task(), the only other user of page_cgroup_ino(), persuaded me. It looks as if it currently leaves out tail pages of the selected memcg, by mistake: whereas hwpoison_inject() uses compound_head() and expects the tails to be included. So hwpoison testing coverage has probably been restricted by the wrong output from page_cgroup_ino() (if that memcg filter is used at all): in the short term, it might be safer not to enable wider coverage there, but long term we would regret that. This is based on a patch originally written by Hugh Dickins and retains most of the original commit log [1] The patch was changed to use folio_memcg_check(page_folio(page)) instead of page_memcg_check(compound_head(page)) based on discussions with Matthew Wilcox; where he stated that callers of page_memcg_check() should stop using it due to the ambiguity around tail pages -- instead they should use folio_memcg_check() and handle tail pages themselves. Link: https://lkml.kernel.org/r/20230412003451.4018887-1-yosryahmed@google.com Link: https://lore.kernel.org/linux-mm/20230313083452.1319968-1-yosryahmed@google.com/ [1] Signed-off-by: Yosry Ahmed <yosryahmed@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Shakeel Butt <shakeelb@google.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Florian Schmidt
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6b0ba2abbe |
memcg v1: provide read access to memory.pressure_level
cgroups v1 has a unique way of setting up memory pressure notifications: the user opens "memory.pressure_level" of the cgroup they want to monitor for pressure, then open "cgroup.event_control" and write the fd (among other things) to that file. memory.pressure_level has no other use, specifically it does not support any read or write operations. Consequently, no handlers are provided, and cgroup_file_mode() sets the permissions to 000. However, to actually use the mechanism, the subscribing user must have read access to the file and open the fd for reading, see memcg_write_event_control(). This is all fine as long as the subscribing process runs as root and is otherwise unconfined by further restrictions. However, if you add strict access controls such as selinux, the permission bits will be enforced, and opening memory.pressure_level for reading will fail, preventing the process from subscribing, even as root. To work around this issue, introduce a dummy read handler. When memory.pressure_level is created, cgroup_file_mode() will notice the existence of a handler, and therefore add read permissions to the file. Link: https://lkml.kernel.org/r/20230404105900.2005-1-flosch@nutanix.com Signed-off-by: Florian Schmidt <flosch@nutanix.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Shakeel Butt <shakeelb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Yosry Ahmed
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f9d911ca49 |
memcg: do not modify rstat tree for zero updates
In some situations, we may end up calling memcg_rstat_updated() with a value of 0, which means the stat was not actually updated. An example is if we fail to reclaim any pages in shrink_folio_list(). Do not add the cgroup to the rstat updated tree in this case, to avoid unnecessarily flushing it. Link: https://lkml.kernel.org/r/20230330191801.1967435-9-yosryahmed@google.com Signed-off-by: Yosry Ahmed <yosryahmed@google.com> Acked-by: Shakeel Butt <shakeelb@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Michal Koutný <mkoutny@suse.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Tejun Heo <tj@kernel.org> Cc: Vasily Averin <vasily.averin@linux.dev> Cc: Zefan Li <lizefan.x@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Yosry Ahmed
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4009b2f188 |
workingset: memcg: sleep when flushing stats in workingset_refault()
In workingset_refault(), we call mem_cgroup_flush_stats_atomic_ratelimited() to read accurate stats within an RCU read section and with sleeping disallowed. Move the call above the RCU read section to make it non-atomic. Flushing is an expensive operation that scales with the number of cpus and the number of cgroups in the system, so avoid doing it atomically where possible. Since workingset_refault() is the only caller of mem_cgroup_flush_stats_atomic_ratelimited(), just make it non-atomic, and rename it to mem_cgroup_flush_stats_ratelimited(). Link: https://lkml.kernel.org/r/20230330191801.1967435-7-yosryahmed@google.com Signed-off-by: Yosry Ahmed <yosryahmed@google.com> Acked-by: Shakeel Butt <shakeelb@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michal Koutný <mkoutny@suse.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Tejun Heo <tj@kernel.org> Cc: Vasily Averin <vasily.averin@linux.dev> Cc: Zefan Li <lizefan.x@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Yosry Ahmed
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9fad9aee1f |
memcg: sleep during flushing stats in safe contexts
Currently, all contexts that flush memcg stats do so with sleeping not allowed. Some of these contexts are perfectly safe to sleep in, such as reading cgroup files from userspace or the background periodic flusher. Flushing is an expensive operation that scales with the number of cpus and the number of cgroups in the system, so avoid doing it atomically where possible. Refactor the code to make mem_cgroup_flush_stats() non-atomic (aka sleepable), and provide a separate atomic version. The atomic version is used in reclaim, refault, writeback, and in mem_cgroup_usage(). All other code paths are left to use the non-atomic version. This includes callbacks for userspace reads and the periodic flusher. Since refault is the only caller of mem_cgroup_flush_stats_ratelimited(), change it to mem_cgroup_flush_stats_atomic_ratelimited(). Reclaim and refault code paths are modified to do non-atomic flushing in separate later patches -- so it will eventually be changed back to mem_cgroup_flush_stats_ratelimited(). Link: https://lkml.kernel.org/r/20230330191801.1967435-6-yosryahmed@google.com Signed-off-by: Yosry Ahmed <yosryahmed@google.com> Acked-by: Shakeel Butt <shakeelb@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michal Koutný <mkoutny@suse.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Tejun Heo <tj@kernel.org> Cc: Vasily Averin <vasily.averin@linux.dev> Cc: Zefan Li <lizefan.x@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Yosry Ahmed
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3cd9992b93 |
memcg: replace stats_flush_lock with an atomic
As Johannes notes in [1], stats_flush_lock is currently used to:
(a) Protect updated to stats_flush_threshold.
(b) Protect updates to flush_next_time.
(c) Serializes calls to cgroup_rstat_flush() based on those ratelimits.
However:
1. stats_flush_threshold is already an atomic
2. flush_next_time is not atomic. The writer is locked, but the reader
is lockless. If the reader races with a flush, you could see this:
if (time_after(jiffies, flush_next_time))
spin_trylock()
flush_next_time = now + delay
flush()
spin_unlock()
spin_trylock()
flush_next_time = now + delay
flush()
spin_unlock()
which means we already can get flushes at a higher frequency than
FLUSH_TIME during races. But it isn't really a problem.
The reader could also see garbled partial updates if the compiler
decides to split the write, so it needs at least READ_ONCE and
WRITE_ONCE protection.
3. Serializing cgroup_rstat_flush() calls against the ratelimit
factors is currently broken because of the race in 2. But the race
is actually harmless, all we might get is the occasional earlier
flush. If there is no delta, the flush won't do much. And if there
is, the flush is justified.
So the lock can be removed all together. However, the lock also served
the purpose of preventing a thundering herd problem for concurrent
flushers, see [2]. Use an atomic instead to serve the purpose of
unifying concurrent flushers.
[1]https://lore.kernel.org/lkml/20230323172732.GE739026@cmpxchg.org/
[2]https://lore.kernel.org/lkml/20210716212137.1391164-2-shakeelb@google.com/
Link: https://lkml.kernel.org/r/20230330191801.1967435-5-yosryahmed@google.com
Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vasily Averin <vasily.averin@linux.dev>
Cc: Zefan Li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Yosry Ahmed
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a2174e95cc |
memcg: do not flush stats in irq context
Currently, the only context in which we can invoke an rstat flush from irq context is through mem_cgroup_usage() on the root memcg when called from memcg_check_events(). An rstat flush is an expensive operation that should not be done in irq context, so do not flush stats and use the stale stats in this case. Arguably, usage threshold events are not reliable on the root memcg anyway since its usage is ill-defined. Link: https://lkml.kernel.org/r/20230330191801.1967435-4-yosryahmed@google.com Signed-off-by: Yosry Ahmed <yosryahmed@google.com> Suggested-by: Johannes Weiner <hannes@cmpxchg.org> Suggested-by: Shakeel Butt <shakeelb@google.com> Acked-by: Shakeel Butt <shakeelb@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michal Koutný <mkoutny@suse.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Tejun Heo <tj@kernel.org> Cc: Vasily Averin <vasily.averin@linux.dev> Cc: Zefan Li <lizefan.x@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Yosry Ahmed
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92fbbc7202 |
memcg: rename mem_cgroup_flush_stats_"delayed" to "ratelimited"
mem_cgroup_flush_stats_delayed() suggests his is using a delayed_work, but this is actually sometimes flushing directly from the callsite. What it's doing is ratelimited calls. A better name would be mem_cgroup_flush_stats_ratelimited(). Link: https://lkml.kernel.org/r/20230330191801.1967435-3-yosryahmed@google.com Signed-off-by: Yosry Ahmed <yosryahmed@google.com> Suggested-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Shakeel Butt <shakeelb@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michal Koutný <mkoutny@suse.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Tejun Heo <tj@kernel.org> Cc: Vasily Averin <vasily.averin@linux.dev> Cc: Zefan Li <lizefan.x@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Yosry Ahmed
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8bff9a04ca |
cgroup: rename cgroup_rstat_flush_"irqsafe" to "atomic"
Patch series "memcg: avoid flushing stats atomically where possible", v3. rstat flushing is an expensive operation that scales with the number of cpus and the number of cgroups in the system. The purpose of this series is to minimize the contexts where we flush stats atomically. Patches 1 and 2 are cleanups requested during reviews of prior versions of this series. Patch 3 makes sure we never try to flush from within an irq context. Patches 4 to 7 introduce separate variants of mem_cgroup_flush_stats() for atomic and non-atomic flushing, and make sure we only flush the stats atomically when necessary. Patch 8 is a slightly tangential optimization that limits the work done by rstat flushing in some scenarios. This patch (of 8): cgroup_rstat_flush_irqsafe() can be a confusing name. It may read as "irqs are disabled throughout", which is what the current implementation does (currently under discussion [1]), but is not the intention. The intention is that this function is safe to call from atomic contexts. Name it as such. Link: https://lkml.kernel.org/r/20230330191801.1967435-1-yosryahmed@google.com Link: https://lkml.kernel.org/r/20230330191801.1967435-2-yosryahmed@google.com Signed-off-by: Yosry Ahmed <yosryahmed@google.com> Suggested-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Shakeel Butt <shakeelb@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michal Koutný <mkoutny@suse.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Tejun Heo <tj@kernel.org> Cc: Vasily Averin <vasily.averin@linux.dev> Cc: Zefan Li <lizefan.x@bytedance.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
|
|
Michal Hocko
|
6a792697a5 |
memcg: do not drain charge pcp caches on remote isolated cpus
Leonardo Bras has noticed that pcp charge cache draining might be disruptive on workloads relying on 'isolated cpus', a feature commonly used on workloads that are sensitive to interruption and context switching such as vRAN and Industrial Control Systems. There are essentially two ways how to approach the issue. We can either allow the pcp cache to be drained on a different rather than a local cpu or avoid remote flushing on isolated cpus. The current pcp charge cache is really optimized for high performance and it always relies to stick with its cpu. That means it only requires local_lock (preempt_disable on !RT) and draining is handed over to pcp WQ to drain locally again. The former solution (remote draining) would require to add an additional locking to prevent local charges from racing with the draining. This adds an atomic operation to otherwise simple arithmetic fast path in the try_charge path. Another concern is that the remote draining can cause a lock contention for the isolated workloads and therefore interfere with it indirectly via user space interfaces. Another option is to avoid draining scheduling on isolated cpus altogether. That means that those remote cpus would keep their charges even after drain_all_stock returns. This is certainly not optimal either but it shouldn't really cause any major problems. In the worst case (many isolated cpus with charges - each of them with MEMCG_CHARGE_BATCH i.e 64 page) the memory consumption of a memcg would be artificially higher than can be immediately used from other cpus. Theoretically a memcg OOM killer could be triggered pre-maturely. Currently it is not really clear whether this is a practical problem though. Tight memcg limit would be really counter productive to cpu isolated workloads pretty much by definition because any memory reclaimed induced by memcg limit could break user space timing expectations as those usually expect execution in the userspace most of the time. Also charges could be left behind on memcg removal. Any future charge on those isolated cpus will drain that pcp cache so this won't be a permanent leak. Considering cons and pros of both approaches this patch is implementing the second option and simply do not schedule remote draining if the target cpu is isolated. This solution is much more simpler. It doesn't add any new locking and it is more more predictable from the user space POV. Should the pre-mature memcg OOM become a real life problem, we can revisit this decision. [akpm@linux-foundation.org: memcontrol.c needs sched/isolation.h] Link: https://lore.kernel.org/oe-kbuild-all/202303180617.7E3aIlHf-lkp@intel.com/ Link: https://lkml.kernel.org/r/20230317134448.11082-3-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Suggested-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Reported-by: Leonardo Bras <leobras@redhat.com> Acked-by: Shakeel Butt <shakeelb@google.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Frederic Weisbecker <frederic@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
|
Christoph Hellwig
|
66dabbb65d |
mm: return an ERR_PTR from __filemap_get_folio
Instead of returning NULL for all errors, distinguish between: - no entry found and not asked to allocated (-ENOENT) - failed to allocate memory (-ENOMEM) - would block (-EAGAIN) so that callers don't have to guess the error based on the passed in flags. Also pass through the error through the direct callers: filemap_get_folio, filemap_lock_folio filemap_grab_folio and filemap_get_incore_folio. [hch@lst.de: fix null-pointer deref] Link: https://lkml.kernel.org/r/20230310070023.GA13563@lst.de Link: https://lkml.kernel.org/r/20230310043137.GA1624890@u2004 Link: https://lkml.kernel.org/r/20230307143410.28031-8-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> [nilfs2] Cc: Andreas Gruenbacher <agruenba@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
|
Yue Zhao
|
2178e20c24 |
mm, memcg: Prevent memory.soft_limit_in_bytes load/store tearing
The knob for cgroup v1 memory controller: memory.soft_limit_in_bytes is not protected by any locking so it can be modified while it is used. This is not an actual problem because races are unlikely. But it is better to use [READ|WRITE]_ONCE to prevent compiler from doing anything funky. The access of memcg->soft_limit is lockless, so it can be concurrently set at the same time as we are trying to read it. All occurrences of memcg->soft_limit are updated with [READ|WRITE]_ONCE. [findns94@gmail.com: v3] Link: https://lkml.kernel.org/r/20230308162555.14195-5-findns94@gmail.com Link: https://lkml.kernel.org/r/20230306154138.3775-5-findns94@gmail.com Signed-off-by: Yue Zhao <findns94@gmail.com> Acked-by: Shakeel Butt <shakeelb@google.com> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Tang Yizhou <tangyeechou@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
|
|
Yue Zhao
|
17c56de6a8 |
mm, memcg: Prevent memory.oom_control load/store tearing
The knob for cgroup v1 memory controller: memory.oom_control is not protected by any locking so it can be modified while it is used. This is not an actual problem because races are unlikely. But it is better to use [READ|WRITE]_ONCE to prevent compiler from doing anything funky. The access of memcg->oom_kill_disable is lockless, so it can be concurrently set at the same time as we are trying to read it. All occurrences of memcg->oom_kill_disable are updated with [READ|WRITE]_ONCE. [findns94@gmail.com: v3] Link: https://lkml.kernel.org/r/20230308162555.14195-4-findns94@gmail.com Link: https://lkml.kernel.org/r/20230306154138.377-4-findns94@gmail.com Signed-off-by: Yue Zhao <findns94@gmail.com> Acked-by: Shakeel Butt <shakeelb@google.com> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Tang Yizhou <tangyeechou@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
|
|
Yue Zhao
|
82b3aa2681 |
mm, memcg: Prevent memory.swappiness load/store tearing
The knob for cgroup v1 memory controller: memory.swappiness is not protected by any locking so it can be modified while it is used. This is not an actual problem because races are unlikely. But it is better to use [READ|WRITE]_ONCE to prevent compiler from doing anything funky. The access of memcg->swappiness and vm_swappiness is lockless, so both of them can be concurrently set at the same time as we are trying to read them. All occurrences of memcg->swappiness and vm_swappiness are updated with [READ|WRITE]_ONCE. [findns94@gmail.com: v3] Link: https://lkml.kernel.org/r/20230308162555.14195-3-findns94@gmail.com Link: https://lkml.kernel.org/r/20230306154138.3775-3-findns94@gmail.com Signed-off-by: Yue Zhao <findns94@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Shakeel Butt <shakeelb@google.com> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Tang Yizhou <tangyeechou@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
|
|
Yue Zhao
|
eaf7b66b76 |
mm, memcg: Prevent memory.oom.group load/store tearing
Patch series "mm, memcg: cgroup v1 and v2 tunable load/store tearing fixes", v2. This patch series helps to prevent load/store tearing in several cgroup knobs. As kindly pointed out by Michal Hocko and Roman Gushchin , the changelog has been rephrased. Besides, more knobs were checked, according to kind suggestions from Shakeel Butt and Muchun Song. This patch (of 4): The knob for cgroup v2 memory controller: memory.oom.group is not protected by any locking so it can be modified while it is used. This is not an actual problem because races are unlikely (the knob is usually configured long before any workloads hits actual memcg oom) but it is better to use READ_ONCE/WRITE_ONCE to prevent compiler from doing anything funky. The access of memcg->oom_group is lockless, so it can be concurrently set at the same time as we are trying to read it. Link: https://lkml.kernel.org/r/20230306154138.3775-1-findns94@gmail.com Link: https://lkml.kernel.org/r/20230306154138.3775-2-findns94@gmail.com Signed-off-by: Yue Zhao <findns94@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Shakeel Butt <shakeelb@google.com> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Tang Yizhou <tangyeechou@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
|
Linus Torvalds
|
3822a7c409 |
- Daniel Verkamp has contributed a memfd series ("mm/memfd: add
F_SEAL_EXEC") which permits the setting of the memfd execute bit at
memfd creation time, with the option of sealing the state of the X bit.
- Peter Xu adds a patch series ("mm/hugetlb: Make huge_pte_offset()
thread-safe for pmd unshare") which addresses a rare race condition
related to PMD unsharing.
- Several folioification patch serieses from Matthew Wilcox, Vishal
Moola, Sidhartha Kumar and Lorenzo Stoakes
- Johannes Weiner has a series ("mm: push down lock_page_memcg()") which
does perform some memcg maintenance and cleanup work.
- SeongJae Park has added DAMOS filtering to DAMON, with the series
"mm/damon/core: implement damos filter". These filters provide users
with finer-grained control over DAMOS's actions. SeongJae has also done
some DAMON cleanup work.
- Kairui Song adds a series ("Clean up and fixes for swap").
- Vernon Yang contributed the series "Clean up and refinement for maple
tree".
- Yu Zhao has contributed the "mm: multi-gen LRU: memcg LRU" series. It
adds to MGLRU an LRU of memcgs, to improve the scalability of global
reclaim.
- David Hildenbrand has added some userfaultfd cleanup work in the
series "mm: uffd-wp + change_protection() cleanups".
- Christoph Hellwig has removed the generic_writepages() library
function in the series "remove generic_writepages".
- Baolin Wang has performed some maintenance on the compaction code in
his series "Some small improvements for compaction".
- Sidhartha Kumar is doing some maintenance work on struct page in his
series "Get rid of tail page fields".
- David Hildenbrand contributed some cleanup, bugfixing and
generalization of pte management and of pte debugging in his series "mm:
support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures with swap
PTEs".
- Mel Gorman and Neil Brown have removed the __GFP_ATOMIC allocation
flag in the series "Discard __GFP_ATOMIC".
- Sergey Senozhatsky has improved zsmalloc's memory utilization with his
series "zsmalloc: make zspage chain size configurable".
- Joey Gouly has added prctl() support for prohibiting the creation of
writeable+executable mappings. The previous BPF-based approach had
shortcomings. See "mm: In-kernel support for memory-deny-write-execute
(MDWE)".
- Waiman Long did some kmemleak cleanup and bugfixing in the series
"mm/kmemleak: Simplify kmemleak_cond_resched() & fix UAF".
- T.J. Alumbaugh has contributed some MGLRU cleanup work in his series
"mm: multi-gen LRU: improve".
- Jiaqi Yan has provided some enhancements to our memory error
statistics reporting, mainly by presenting the statistics on a per-node
basis. See the series "Introduce per NUMA node memory error
statistics".
- Mel Gorman has a second and hopefully final shot at fixing a CPU-hog
regression in compaction via his series "Fix excessive CPU usage during
compaction".
- Christoph Hellwig does some vmalloc maintenance work in the series
"cleanup vfree and vunmap".
- Christoph Hellwig has removed block_device_operations.rw_page() in ths
series "remove ->rw_page".
- We get some maple_tree improvements and cleanups in Liam Howlett's
series "VMA tree type safety and remove __vma_adjust()".
- Suren Baghdasaryan has done some work on the maintainability of our
vm_flags handling in the series "introduce vm_flags modifier functions".
- Some pagemap cleanup and generalization work in Mike Rapoport's series
"mm, arch: add generic implementation of pfn_valid() for FLATMEM" and
"fixups for generic implementation of pfn_valid()"
- Baoquan He has done some work to make /proc/vmallocinfo and
/proc/kcore better represent the real state of things in his series
"mm/vmalloc.c: allow vread() to read out vm_map_ram areas".
- Jason Gunthorpe rationalized the GUP system's interface to the rest of
the kernel in the series "Simplify the external interface for GUP".
- SeongJae Park wishes to migrate people from DAMON's debugfs interface
over to its sysfs interface. To support this, we'll temporarily be
printing warnings when people use the debugfs interface. See the series
"mm/damon: deprecate DAMON debugfs interface".
- Andrey Konovalov provided the accurately named "lib/stackdepot: fixes
and clean-ups" series.
- Huang Ying has provided a dramatic reduction in migration's TLB flush
IPI rates with the series "migrate_pages(): batch TLB flushing".
- Arnd Bergmann has some objtool fixups in "objtool warning fixes".
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Merge tag 'mm-stable-2023-02-20-13-37' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- Daniel Verkamp has contributed a memfd series ("mm/memfd: add
F_SEAL_EXEC") which permits the setting of the memfd execute bit at
memfd creation time, with the option of sealing the state of the X
bit.
- Peter Xu adds a patch series ("mm/hugetlb: Make huge_pte_offset()
thread-safe for pmd unshare") which addresses a rare race condition
related to PMD unsharing.
- Several folioification patch serieses from Matthew Wilcox, Vishal
Moola, Sidhartha Kumar and Lorenzo Stoakes
- Johannes Weiner has a series ("mm: push down lock_page_memcg()")
which does perform some memcg maintenance and cleanup work.
- SeongJae Park has added DAMOS filtering to DAMON, with the series
"mm/damon/core: implement damos filter".
These filters provide users with finer-grained control over DAMOS's
actions. SeongJae has also done some DAMON cleanup work.
- Kairui Song adds a series ("Clean up and fixes for swap").
- Vernon Yang contributed the series "Clean up and refinement for maple
tree".
- Yu Zhao has contributed the "mm: multi-gen LRU: memcg LRU" series. It
adds to MGLRU an LRU of memcgs, to improve the scalability of global
reclaim.
- David Hildenbrand has added some userfaultfd cleanup work in the
series "mm: uffd-wp + change_protection() cleanups".
- Christoph Hellwig has removed the generic_writepages() library
function in the series "remove generic_writepages".
- Baolin Wang has performed some maintenance on the compaction code in
his series "Some small improvements for compaction".
- Sidhartha Kumar is doing some maintenance work on struct page in his
series "Get rid of tail page fields".
- David Hildenbrand contributed some cleanup, bugfixing and
generalization of pte management and of pte debugging in his series
"mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures with
swap PTEs".
- Mel Gorman and Neil Brown have removed the __GFP_ATOMIC allocation
flag in the series "Discard __GFP_ATOMIC".
- Sergey Senozhatsky has improved zsmalloc's memory utilization with
his series "zsmalloc: make zspage chain size configurable".
- Joey Gouly has added prctl() support for prohibiting the creation of
writeable+executable mappings.
The previous BPF-based approach had shortcomings. See "mm: In-kernel
support for memory-deny-write-execute (MDWE)".
- Waiman Long did some kmemleak cleanup and bugfixing in the series
"mm/kmemleak: Simplify kmemleak_cond_resched() & fix UAF".
- T.J. Alumbaugh has contributed some MGLRU cleanup work in his series
"mm: multi-gen LRU: improve".
- Jiaqi Yan has provided some enhancements to our memory error
statistics reporting, mainly by presenting the statistics on a
per-node basis. See the series "Introduce per NUMA node memory error
statistics".
- Mel Gorman has a second and hopefully final shot at fixing a CPU-hog
regression in compaction via his series "Fix excessive CPU usage
during compaction".
- Christoph Hellwig does some vmalloc maintenance work in the series
"cleanup vfree and vunmap".
- Christoph Hellwig has removed block_device_operations.rw_page() in
ths series "remove ->rw_page".
- We get some maple_tree improvements and cleanups in Liam Howlett's
series "VMA tree type safety and remove __vma_adjust()".
- Suren Baghdasaryan has done some work on the maintainability of our
vm_flags handling in the series "introduce vm_flags modifier
functions".
- Some pagemap cleanup and generalization work in Mike Rapoport's
series "mm, arch: add generic implementation of pfn_valid() for
FLATMEM" and "fixups for generic implementation of pfn_valid()"
- Baoquan He has done some work to make /proc/vmallocinfo and
/proc/kcore better represent the real state of things in his series
"mm/vmalloc.c: allow vread() to read out vm_map_ram areas".
- Jason Gunthorpe rationalized the GUP system's interface to the rest
of the kernel in the series "Simplify the external interface for
GUP".
- SeongJae Park wishes to migrate people from DAMON's debugfs interface
over to its sysfs interface. To support this, we'll temporarily be
printing warnings when people use the debugfs interface. See the
series "mm/damon: deprecate DAMON debugfs interface".
- Andrey Konovalov provided the accurately named "lib/stackdepot: fixes
and clean-ups" series.
- Huang Ying has provided a dramatic reduction in migration's TLB flush
IPI rates with the series "migrate_pages(): batch TLB flushing".
- Arnd Bergmann has some objtool fixups in "objtool warning fixes".
* tag 'mm-stable-2023-02-20-13-37' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (505 commits)
include/linux/migrate.h: remove unneeded externs
mm/memory_hotplug: cleanup return value handing in do_migrate_range()
mm/uffd: fix comment in handling pte markers
mm: change to return bool for isolate_movable_page()
mm: hugetlb: change to return bool for isolate_hugetlb()
mm: change to return bool for isolate_lru_page()
mm: change to return bool for folio_isolate_lru()
objtool: add UACCESS exceptions for __tsan_volatile_read/write
kmsan: disable ftrace in kmsan core code
kasan: mark addr_has_metadata __always_inline
mm: memcontrol: rename memcg_kmem_enabled()
sh: initialize max_mapnr
m68k/nommu: add missing definition of ARCH_PFN_OFFSET
mm: percpu: fix incorrect size in pcpu_obj_full_size()
maple_tree: reduce stack usage with gcc-9 and earlier
mm: page_alloc: call panic() when memoryless node allocation fails
mm: multi-gen LRU: avoid futile retries
migrate_pages: move THP/hugetlb migration support check to simplify code
migrate_pages: batch flushing TLB
migrate_pages: share more code between _unmap and _move
...
|
|
Baolin Wang
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f7f9c00dfa |
mm: change to return bool for isolate_lru_page()
The isolate_lru_page() can only return 0 or -EBUSY, and most users did not care about the negative error of isolate_lru_page(), except one user in add_page_for_migration(). So we can convert the isolate_lru_page() to return a boolean value, which can help to make the code more clear when checking the return value of isolate_lru_page(). Also convert all users' logic of checking the isolation state. No functional changes intended. Link: https://lkml.kernel.org/r/3074c1ab628d9dbf139b33f248a8bc253a3f95f0.1676424378.git.baolin.wang@linux.alibaba.com Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
|
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Roman Gushchin
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f7a449f779 |
mm: memcontrol: rename memcg_kmem_enabled()
Currently there are two kmem-related helper functions with a confusing semantics: memcg_kmem_enabled() and mem_cgroup_kmem_disabled(). The problem is that an obvious expectation memcg_kmem_enabled() == !mem_cgroup_kmem_disabled(), can be false. mem_cgroup_kmem_disabled() is similar to mem_cgroup_disabled(): it returns true only if CONFIG_MEMCG_KMEM is not set or the kmem accounting is disabled using a boot time kernel option "cgroup.memory=nokmem". It never changes the value dynamically. memcg_kmem_enabled() is different: it always returns false until the first non-root memory cgroup will get online (assuming the kernel memory accounting is enabled). It's goal is to improve the performance on systems without the cgroupfs mounted/memory controller enabled or on the systems with only the root memory cgroup. To make things more obvious and avoid potential bugs, let's rename memcg_kmem_enabled() to memcg_kmem_online(). Link: https://lkml.kernel.org/r/20230213192922.1146370-1-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: Muchun Song <songmuchun@bytedance.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Dennis Zhou <dennis@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
|
Yafang Shao
|
b6c1a8af5b |
mm: memcontrol: add new kernel parameter cgroup.memory=nobpf
Add new kernel parameter cgroup.memory=nobpf to allow user disable bpf memory accounting. This is a preparation for the followup patch. Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Link: https://lore.kernel.org/r/20230210154734.4416-2-laoar.shao@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
|
|
T.J. Alumbaugh
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36c7b4db7c |
mm: multi-gen LRU: section for memcg LRU
Move memcg LRU code into a dedicated section. Improve the design doc to outline its architecture. Link: https://lkml.kernel.org/r/20230118001827.1040870-5-talumbau@google.com Signed-off-by: T.J. Alumbaugh <talumbau@google.com> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
|
|
Matthew Wilcox (Oracle)
|
75376c6fb9 |
mm: convert mem_cgroup_css_from_page() to mem_cgroup_css_from_folio()
Only one caller doesn't have a folio, so move the page_folio() call to that one caller from mem_cgroup_css_from_folio(). Link: https://lkml.kernel.org/r/20230116192507.2146150-3-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
|
|
Andrew Morton
|
5ab0fc155d |
Sync mm-stable with mm-hotfixes-stable to pick up dependent patches
Merge branch 'mm-hotfixes-stable' into mm-stable |
|
|
Michal Hocko
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55ab834a86 |
Revert "mm: add nodes= arg to memory.reclaim"
This reverts commit |
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Matthew Wilcox
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becacb04fd |
mm: memcg: add folio_memcg_check()
Patch series "mm: convert page_idle/damon to use folios", v4. This patch (of 8): Convert page_memcg_check() into folio_memcg_check() and add a page_memcg_check() wrapper. The behaviour of page_memcg_check() is unchanged; tail pages always had a NULL ->memcg_data. Link: https://lkml.kernel.org/r/20221230070849.63358-1-wangkefeng.wang@huawei.com Link: https://lkml.kernel.org/r/20221230070849.63358-2-wangkefeng.wang@huawei.com Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: David Hildenbrand <david@redhat.com> Cc: SeongJae Park <sj@kernel.org> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Yu Zhao
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e4dde56cd2 |
mm: multi-gen LRU: per-node lru_gen_folio lists
For each node, memcgs are divided into two generations: the old and the young. For each generation, memcgs are randomly sharded into multiple bins to improve scalability. For each bin, an RCU hlist_nulls is virtually divided into three segments: the head, the tail and the default. An onlining memcg is added to the tail of a random bin in the old generation. The eviction starts at the head of a random bin in the old generation. The per-node memcg generation counter, whose reminder (mod 2) indexes the old generation, is incremented when all its bins become empty. There are four operations: 1. MEMCG_LRU_HEAD, which moves an memcg to the head of a random bin in its current generation (old or young) and updates its "seg" to "head"; 2. MEMCG_LRU_TAIL, which moves an memcg to the tail of a random bin in its current generation (old or young) and updates its "seg" to "tail"; 3. MEMCG_LRU_OLD, which moves an memcg to the head of a random bin in the old generation, updates its "gen" to "old" and resets its "seg" to "default"; 4. MEMCG_LRU_YOUNG, which moves an memcg to the tail of a random bin in the young generation, updates its "gen" to "young" and resets its "seg" to "default". The events that trigger the above operations are: 1. Exceeding the soft limit, which triggers MEMCG_LRU_HEAD; 2. The first attempt to reclaim an memcg below low, which triggers MEMCG_LRU_TAIL; 3. The first attempt to reclaim an memcg below reclaimable size threshold, which triggers MEMCG_LRU_TAIL; 4. The second attempt to reclaim an memcg below reclaimable size threshold, which triggers MEMCG_LRU_YOUNG; 5. Attempting to reclaim an memcg below min, which triggers MEMCG_LRU_YOUNG; 6. Finishing the aging on the eviction path, which triggers MEMCG_LRU_YOUNG; 7. Offlining an memcg, which triggers MEMCG_LRU_OLD. Note that memcg LRU only applies to global reclaim, and the round-robin incrementing of their max_seq counters ensures the eventual fairness to all eligible memcgs. For memcg reclaim, it still relies on mem_cgroup_iter(). Link: https://lkml.kernel.org/r/20221222041905.2431096-7-yuzhao@google.com Signed-off-by: Yu Zhao <yuzhao@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Michael Larabel <Michael@MichaelLarabel.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Johannes Weiner
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da34a8484d |
mm: memcontrol: deprecate charge moving
Charge moving mode in cgroup1 allows memory to follow tasks as they migrate between cgroups. This is, and always has been, a questionable thing to do - for several reasons. First, it's expensive. Pages need to be identified, locked and isolated from various MM operations, and reassigned, one by one. Second, it's unreliable. Once pages are charged to a cgroup, there isn't always a clear owner task anymore. Cache isn't moved at all, for example. Mapped memory is moved - but if trylocking or isolating a page fails, it's arbitrarily left behind. Frequent moving between domains may leave a task's memory scattered all over the place. Third, it isn't really needed. Launcher tasks can kick off workload tasks directly in their target cgroup. Using dedicated per-workload groups allows fine-grained policy adjustments - no need to move tasks and their physical pages between control domains. The feature was never forward-ported to cgroup2, and it hasn't been missed. Despite it being a niche usecase, the maintenance overhead of supporting it is enormous. Because pages are moved while they are live and subject to various MM operations, the synchronization rules are complicated. There are lock_page_memcg() in MM and FS code, which non-cgroup people don't understand. In some cases we've been able to shift code and cgroup API calls around such that we can rely on native locking as much as possible. But that's fragile, and sometimes we need to hold MM locks for longer than we otherwise would (pte lock e.g.). Mark the feature deprecated. Hopefully we can remove it soon. And backport into -stable kernels so that people who develop against earlier kernels are warned about this deprecation as early as possible. [akpm@linux-foundation.org: fix memory.rst underlining] Link: https://lkml.kernel.org/r/Y5COd+qXwk/S+n8N@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Shakeel Butt <shakeelb@google.com> Acked-by: Hugh Dickins <hughd@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Johannes Weiner
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4e0cf05f60 |
mm: memcontrol: skip moving non-present pages that are mapped elsewhere
Patch series "mm: push down lock_page_memcg()", v2. This patch (of 3): During charge moving, the pte lock and the page lock cover nearly all cases of stabilizing page_mapped(). The only exception is when we're looking at a non-present pte and find a page in the page cache or in the swapcache: if the page is mapped elsewhere, it can become unmapped outside of our control. For this reason, rmap needs lock_page_memcg(). We don't like cgroup-specific locks in generic MM code - especially in performance-critical MM code - and for a legacy feature that's unlikely to have many users left - if any. So remove the exception. Arguably that's better semantics anyway: the page is shared, and another process seems to be the more active user. Once we stop moving such pages, rmap doesn't need lock_page_memcg() anymore. The next patch will remove it. Link: https://lkml.kernel.org/r/20221206171340.139790-1-hannes@cmpxchg.org Link: https://lkml.kernel.org/r/20221206171340.139790-2-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Suggested-by: Hugh Dickins <hughd@google.com> Acked-by: Hugh Dickins <hughd@google.com> Acked-by: Shakeel Butt <shakeelb@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Hugh Dickins
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c449deb2b9 |
mm: memcg: fix swapcached stat accounting
I'd been worried by high "swapcached" counts in memcg OOM reports, thought we had a problem freeing swapcache, but it was just the accounting that was wrong. Two issues: 1. When __remove_mapping() removes swapcache, __delete_from_swap_cache() relies on memcg_data for the right counts to be updated; but that had already been reset by mem_cgroup_swapout(). Swap those calls around - mem_cgroup_swapout() does not require the swapcached flag to be set. 6.1 commit |
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Mina Almasry
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12a5d39552 |
mm: add nodes= arg to memory.reclaim
The nodes= arg instructs the kernel to only scan the given nodes for
proactive reclaim. For example use cases, consider a 2 tier memory
system:
nodes 0,1 -> top tier
nodes 2,3 -> second tier
$ echo "1m nodes=0" > memory.reclaim
This instructs the kernel to attempt to reclaim 1m memory from node 0.
Since node 0 is a top tier node, demotion will be attempted first. This
is useful to direct proactive reclaim to specific nodes that are under
pressure.
$ echo "1m nodes=2,3" > memory.reclaim
This instructs the kernel to attempt to reclaim 1m memory in the second
tier, since this tier of memory has no demotion targets the memory will be
reclaimed.
$ echo "1m nodes=0,1" > memory.reclaim
Instructs the kernel to reclaim memory from the top tier nodes, which can
be desirable according to the userspace policy if there is pressure on the
top tiers. Since these nodes have demotion targets, the kernel will
attempt demotion first.
Since commit
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Andrew Morton
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3b91010500 | Merge branch 'mm-hotfixes-stable' into mm-stable | |
Tejun Heo
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4a7ba45b1a |
memcg: fix possible use-after-free in memcg_write_event_control()
memcg_write_event_control() accesses the dentry->d_name of the specified control fd to route the write call. As a cgroup interface file can't be renamed, it's safe to access d_name as long as the specified file is a regular cgroup file. Also, as these cgroup interface files can't be removed before the directory, it's safe to access the parent too. Prior to |
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Johannes Weiner
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57e9cc50f4 |
mm: vmscan: split khugepaged stats from direct reclaim stats
Direct reclaim stats are useful for identifying a potential source for
application latency, as well as spotting issues with kswapd. However,
khugepaged currently distorts the picture: as a kernel thread it doesn't
impose allocation latencies on userspace, and it explicitly opts out of
kswapd reclaim. Its activity showing up in the direct reclaim stats is
misleading. Counting it as kswapd reclaim could also cause confusion when
trying to understand actual kswapd behavior.
Break out khugepaged from the direct reclaim counters into new
pgsteal_khugepaged, pgdemote_khugepaged, pgscan_khugepaged counters.
Test with a huge executable (CONFIG_READ_ONLY_THP_FOR_FS):
pgsteal_kswapd 1342185
pgsteal_direct 0
pgsteal_khugepaged 3623
pgscan_kswapd
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Andrew Morton
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a38358c934 | Merge branch 'mm-hotfixes-stable' into mm-stable | |
Li Liguang
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cd08d80ecd |
mm: correctly charge compressed memory to its memcg
Kswapd will reclaim memory when memory pressure is high, the annonymous
memory will be compressed and stored in the zpool if zswap is enabled.
The memcg_kmem_bypass() in get_obj_cgroup_from_page() will bypass the
kernel thread and cause the compressed memory not be charged to its memory
cgroup.
Remove the memcg_kmem_bypass() call and properly charge compressed memory
to its corresponding memory cgroup.
Link: https://lore.kernel.org/linux-mm/CALvZod4nnn8BHYqAM4xtcR0Ddo2-Wr8uKm9h_CHWUaXw7g_DCg@mail.gmail.com/
Link: https://lkml.kernel.org/r/20221114194828.100822-1-hannes@cmpxchg.org
Fixes:
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Matthew Wilcox (Oracle)
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524984ff66 |
mm: convert find_get_incore_page() to filemap_get_incore_folio()
Return the containing folio instead of the precise page. One of the callers wants the folio and the other can do the folio->page conversion itself. Nets 442 bytes of text size reduction, 478 bytes removed and 36 bytes added. Link: https://lkml.kernel.org/r/20221019183332.2802139-4-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Kamalesh Babulal
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7848ed6284 |
mm: memcontrol: use mem_cgroup_is_root() helper
Replace the checks for memcg is root memcg, with mem_cgroup_is_root() helper. Link: https://lkml.kernel.org/r/20220930134433.338103-1-kamalesh.babulal@oracle.com Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kamalesh Babulal <kamalesh.babulal@oracle.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Shakeel Butt <shakeelb@google.com> Cc: Tom Hromatka <tom.hromatka@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Linus Torvalds
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27bc50fc90 |
- Yu Zhao's Multi-Gen LRU patches are here. They've been under test in
linux-next for a couple of months without, to my knowledge, any negative reports (or any positive ones, come to that). - Also the Maple Tree from Liam R. Howlett. An overlapping range-based tree for vmas. It it apparently slight more efficient in its own right, but is mainly targeted at enabling work to reduce mmap_lock contention. Liam has identified a number of other tree users in the kernel which could be beneficially onverted to mapletrees. Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat (https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com). This has yet to be addressed due to Liam's unfortunately timed vacation. He is now back and we'll get this fixed up. - Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer. It uses clang-generated instrumentation to detect used-unintialized bugs down to the single bit level. KMSAN keeps finding bugs. New ones, as well as the legacy ones. - Yang Shi adds a userspace mechanism (madvise) to induce a collapse of memory into THPs. - Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to support file/shmem-backed pages. - userfaultfd updates from Axel Rasmussen - zsmalloc cleanups from Alexey Romanov - cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and memory-failure - Huang Ying adds enhancements to NUMA balancing memory tiering mode's page promotion, with a new way of detecting hot pages. - memcg updates from Shakeel Butt: charging optimizations and reduced memory consumption. - memcg cleanups from Kairui Song. - memcg fixes and cleanups from Johannes Weiner. - Vishal Moola provides more folio conversions - Zhang Yi removed ll_rw_block() :( - migration enhancements from Peter Xu - migration error-path bugfixes from Huang Ying - Aneesh Kumar added ability for a device driver to alter the memory tiering promotion paths. For optimizations by PMEM drivers, DRM drivers, etc. - vma merging improvements from Jakub Matěn. - NUMA hinting cleanups from David Hildenbrand. - xu xin added aditional userspace visibility into KSM merging activity. - THP & KSM code consolidation from Qi Zheng. - more folio work from Matthew Wilcox. - KASAN updates from Andrey Konovalov. - DAMON cleanups from Kaixu Xia. - DAMON work from SeongJae Park: fixes, cleanups. - hugetlb sysfs cleanups from Muchun Song. - Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core. -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCY0HaPgAKCRDdBJ7gKXxA joPjAQDZ5LlRCMWZ1oxLP2NOTp6nm63q9PWcGnmY50FjD/dNlwEAnx7OejCLWGWf bbTuk6U2+TKgJa4X7+pbbejeoqnt5QU= =xfWx -----END PGP SIGNATURE----- Merge tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in linux-next for a couple of months without, to my knowledge, any negative reports (or any positive ones, come to that). - Also the Maple Tree from Liam Howlett. An overlapping range-based tree for vmas. It it apparently slightly more efficient in its own right, but is mainly targeted at enabling work to reduce mmap_lock contention. Liam has identified a number of other tree users in the kernel which could be beneficially onverted to mapletrees. Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat at [1]. This has yet to be addressed due to Liam's unfortunately timed vacation. He is now back and we'll get this fixed up. - Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer. It uses clang-generated instrumentation to detect used-unintialized bugs down to the single bit level. KMSAN keeps finding bugs. New ones, as well as the legacy ones. - Yang Shi adds a userspace mechanism (madvise) to induce a collapse of memory into THPs. - Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to support file/shmem-backed pages. - userfaultfd updates from Axel Rasmussen - zsmalloc cleanups from Alexey Romanov - cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and memory-failure - Huang Ying adds enhancements to NUMA balancing memory tiering mode's page promotion, with a new way of detecting hot pages. - memcg updates from Shakeel Butt: charging optimizations and reduced memory consumption. - memcg cleanups from Kairui Song. - memcg fixes and cleanups from Johannes Weiner. - Vishal Moola provides more folio conversions - Zhang Yi removed ll_rw_block() :( - migration enhancements from Peter Xu - migration error-path bugfixes from Huang Ying - Aneesh Kumar added ability for a device driver to alter the memory tiering promotion paths. For optimizations by PMEM drivers, DRM drivers, etc. - vma merging improvements from Jakub Matěn. - NUMA hinting cleanups from David Hildenbrand. - xu xin added aditional userspace visibility into KSM merging activity. - THP & KSM code consolidation from Qi Zheng. - more folio work from Matthew Wilcox. - KASAN updates from Andrey Konovalov. - DAMON cleanups from Kaixu Xia. - DAMON work from SeongJae Park: fixes, cleanups. - hugetlb sysfs cleanups from Muchun Song. - Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core. Link: https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com [1] * tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (555 commits) hugetlb: allocate vma lock for all sharable vmas hugetlb: take hugetlb vma_lock when clearing vma_lock->vma pointer hugetlb: fix vma lock handling during split vma and range unmapping mglru: mm/vmscan.c: fix imprecise comments mm/mglru: don't sync disk for each aging cycle mm: memcontrol: drop dead CONFIG_MEMCG_SWAP config symbol mm: memcontrol: use do_memsw_account() in a few more places mm: memcontrol: deprecate swapaccounting=0 mode mm: memcontrol: don't allocate cgroup swap arrays when memcg is disabled mm/secretmem: remove reduntant return value mm/hugetlb: add available_huge_pages() func mm: remove unused inline functions from include/linux/mm_inline.h selftests/vm: add selftest for MADV_COLLAPSE of uffd-minor memory selftests/vm: add file/shmem MADV_COLLAPSE selftest for cleared pmd selftests/vm: add thp collapse shmem testing selftests/vm: add thp collapse file and tmpfs testing selftests/vm: modularize thp collapse memory operations selftests/vm: dedup THP helpers mm/khugepaged: add tracepoint to hpage_collapse_scan_file() mm/madvise: add file and shmem support to MADV_COLLAPSE ... |
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Linus Torvalds
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adf4bfc4a9 |
cgroup changes for v6.1-rc1.
* cpuset now support isolated cpus.partition type, which will enable dynamic
CPU isolation.
* pids.peak added to remember the max number of pids used.
* Holes in cgroup namespace plugged.
* Internal cleanups.
Note that for-6.1-fixes was pulled into for-6.1 twice. Both were for
follow-up cleanups and each merge commit has details.
Also,
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Linus Torvalds
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7f6dcffb44 |
Preempt RT cleanups:
Introduce preempt_[dis|enable_nested() and use it to clean up various places which have open coded PREEMPT_RT conditionals. On PREEMPT_RT enabled kernels, spinlocks and rwlocks are neither disabling preemption nor interrupts. Though there are a few places which depend on the implicit preemption/interrupt disable of those locks, e.g. seqcount write sections, per CPU statistics updates etc. PREEMPT_RT added open coded CONFIG_PREEMPT_RT conditionals to disable/enable preemption in the related code parts all over the place. That's hard to read and does not really explain why this is necessary. Linus suggested to use helper functions (preempt_disable_nested() and preempt_enable_nested()) and use those in the affected places. On !RT enabled kernels these functions are NOPs, but contain a lockdep assert to validate that preemption is actually disabled to catch call sites which do not have preemption disabled. Clean up the affected code paths in mm, dentry and lib. -----BEGIN PGP SIGNATURE----- iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAmM9c8MTHHRnbHhAbGlu dXRyb25peC5kZQAKCRCmGPVMDXSYobrrEADHkvkCUHxRlarfinQY2rxEpC4nbnAg ibg+LWpDpqqZwkjADExu6+lsbb0mCdvlFyvSPwY2YcQAkj/bkTAXvdf3KjejTl++ B1J5/Cr5lyyKjajjl1efxdORgATBvwuEjR2moJiU868ZR3K4vgflN9n51A0U+NAn 3kOj/TYotFlyDNJeoK/8edqZwKaueXs3fsYGC1aq2X8mQLI4QDeaHUR6R8CU4w+X bVSIdKNluIYxyc3Eav5sDwzyF6gOSL+9DtZcVyXxJ6+PrkDdkptO23derVHk19WE ymdAwVX6S37L6HNhJgqeScs+s3xD8KDmvu5ktEAtqC0unBP8JwOFZKCZaaYj91j3 iMjMC4UFcXI5sERWhDXTSja2g0pYV6q3myfYfojxe6xXHlrVs42gCzDpOI4LZncM lvPfmhb7JR7zEmBEvVyEOX8B16ecWnUqgihU17a3ogGdKW1PRNWcWj3RmNXDmpGD YZsZSfsawMSJsDIrNRCydXrsiFBNIoVStN7K7c+blnNV8ER5rt24dqCJyUhrl4fB K8hNvDp+T8N0f6nlIUWk42vjhskEo2ijCnpvHSXQc1UL7WmLfaJf3/T9zlufPwqJ 7yVuWd9vZIb3iVAKz+LqOzLlHcgeJmYlbSBsj+Ay1UHPsNgYulDEKcuNniVoG39u zFgHu3OmIRueHA== =3M58 -----END PGP SIGNATURE----- Merge tag 'sched-rt-2022-10-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull preempt RT updates from Thomas Gleixner: "Introduce preempt_[dis|enable_nested() and use it to clean up various places which have open coded PREEMPT_RT conditionals. On PREEMPT_RT enabled kernels, spinlocks and rwlocks are neither disabling preemption nor interrupts. Though there are a few places which depend on the implicit preemption/interrupt disable of those locks, e.g. seqcount write sections, per CPU statistics updates etc. PREEMPT_RT added open coded CONFIG_PREEMPT_RT conditionals to disable/enable preemption in the related code parts all over the place. That's hard to read and does not really explain why this is necessary. Linus suggested to use helper functions (preempt_disable_nested() and preempt_enable_nested()) and use those in the affected places. On !RT enabled kernels these functions are NOPs, but contain a lockdep assert to validate that preemption is actually disabled to catch call sites which do not have preemption disabled. Clean up the affected code paths in mm, dentry and lib" * tag 'sched-rt-2022-10-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: u64_stats: Streamline the implementation flex_proportions: Disable preemption entering the write section. mm/compaction: Get rid of RT ifdeffery mm/memcontrol: Replace the PREEMPT_RT conditionals mm/debug: Provide VM_WARN_ON_IRQS_ENABLED() mm/vmstat: Use preempt_[dis|en]able_nested() dentry: Use preempt_[dis|en]able_nested() preempt: Provide preempt_[dis|en]able_nested() |
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Johannes Weiner
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e55b9f9686 |
mm: memcontrol: drop dead CONFIG_MEMCG_SWAP config symbol
Since
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Johannes Weiner
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b94c4e949c |
mm: memcontrol: use do_memsw_account() in a few more places
It's slightly more descriptive and consistent with other places that distinguish cgroup1's combined memory+swap accounting scheme from cgroup2's dedicated swap accounting. Link: https://lkml.kernel.org/r/20220926135704.400818-4-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Shakeel Butt <shakeelb@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Johannes Weiner
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b25806dcd3 |
mm: memcontrol: deprecate swapaccounting=0 mode
The swapaccounting= commandline option already does very little today. To
close a trivial containment failure case, the swap ownership tracking part
of the swap controller has recently become mandatory (see commit
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Johannes Weiner
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c91bdc9358 |
mm: memcontrol: don't allocate cgroup swap arrays when memcg is disabled
Patch series "memcg swap fix & cleanups". This patch (of 4): Since commit |
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Kairui Song
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c1b8fdae62 |
mm: memcontrol: make cgroup_memory_noswap a static key
cgroup_memory_noswap is used in many hot path, so make it a static key
to lower the kernel overhead.
Using 8G of ZRAM as SWAP, benchmark using `perf stat -d -d -d --repeat 100`
with the following code snip in a non-root cgroup:
#include <stdio.h>
#include <string.h>
#include <linux/mman.h>
#include <sys/mman.h>
#define MB 1024UL * 1024UL
int main(int argc, char **argv){
void *p = mmap(NULL, 8000 * MB, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
memset(p, 0xff, 8000 * MB);
madvise(p, 8000 * MB, MADV_PAGEOUT);
memset(p, 0xff, 8000 * MB);
return 0;
}
Before:
7,021.43 msec task-clock # 0.967 CPUs utilized ( +- 0.03% )
4,010 context-switches # 573.853 /sec ( +- 0.01% )
0 cpu-migrations # 0.000 /sec
2,052,057 page-faults # 293.661 K/sec ( +- 0.00% )
12,616,546,027 cycles # 1.805 GHz ( +- 0.06% ) (39.92%)
156,823,666 stalled-cycles-frontend # 1.25% frontend cycles idle ( +- 0.10% ) (40.25%)
310,130,812 stalled-cycles-backend # 2.47% backend cycles idle ( +- 4.39% ) (40.73%)
18,692,516,591 instructions # 1.49 insn per cycle
# 0.01 stalled cycles per insn ( +- 0.04% ) (40.75%)
4,907,447,976 branches # 702.283 M/sec ( +- 0.05% ) (40.30%)
13,002,578 branch-misses # 0.26% of all branches ( +- 0.08% ) (40.48%)
7,069,786,296 L1-dcache-loads # 1.012 G/sec ( +- 0.03% ) (40.32%)
649,385,847 L1-dcache-load-misses # 9.13% of all L1-dcache accesses ( +- 0.07% ) (40.10%)
1,485,448,688 L1-icache-loads # 212.576 M/sec ( +- 0.15% ) (39.49%)
31,628,457 L1-icache-load-misses # 2.13% of all L1-icache accesses ( +- 0.40% ) (39.57%)
6,667,311 dTLB-loads # 954.129 K/sec ( +- 0.21% ) (39.50%)
5,668,555 dTLB-load-misses # 86.40% of all dTLB cache accesses ( +- 0.12% ) (39.03%)
765 iTLB-loads # 109.476 /sec ( +- 21.81% ) (39.44%)
4,370,351 iTLB-load-misses # 214320.09% of all iTLB cache accesses ( +- 1.44% ) (39.86%)
149,207,254 L1-dcache-prefetches # 21.352 M/sec ( +- 0.13% ) (40.27%)
7.25869 +- 0.00203 seconds time elapsed ( +- 0.03% )
After:
6,576.16 msec task-clock # 0.953 CPUs utilized ( +- 0.10% )
4,020 context-switches # 605.595 /sec ( +- 0.01% )
0 cpu-migrations # 0.000 /sec
2,052,056 page-faults # 309.133 K/sec ( +- 0.00% )
11,967,619,180 cycles # 1.803 GHz ( +- 0.36% ) (38.76%)
161,259,240 stalled-cycles-frontend # 1.38% frontend cycles idle ( +- 0.27% ) (36.58%)
253,605,302 stalled-cycles-backend # 2.16% backend cycles idle ( +- 4.45% ) (34.78%)
19,328,171,892 instructions # 1.65 insn per cycle
# 0.01 stalled cycles per insn ( +- 0.10% ) (31.46%)
5,213,967,902 branches # 785.461 M/sec ( +- 0.18% ) (30.68%)
12,385,170 branch-misses # 0.24% of all branches ( +- 0.26% ) (34.13%)
7,271,687,822 L1-dcache-loads # 1.095 G/sec ( +- 0.12% ) (35.29%)
649,873,045 L1-dcache-load-misses # 8.93% of all L1-dcache accesses ( +- 0.11% ) (41.41%)
1,950,037,608 L1-icache-loads # 293.764 M/sec ( +- 0.33% ) (43.11%)
31,365,566 L1-icache-load-misses # 1.62% of all L1-icache accesses ( +- 0.39% ) (45.89%)
6,767,809 dTLB-loads # 1.020 M/sec ( +- 0.47% ) (48.42%)
6,339,590 dTLB-load-misses # 95.43% of all dTLB cache accesses ( +- 0.50% ) (46.60%)
736 iTLB-loads # 110.875 /sec ( +- 1.79% ) (48.60%)
4,314,836 iTLB-load-misses # 518653.73% of all iTLB cache accesses ( +- 0.63% ) (42.91%)
144,950,156 L1-dcache-prefetches # 21.836 M/sec ( +- 0.37% ) (41.39%)
6.89935 +- 0.00703 seconds time elapsed ( +- 0.10% )
The performance is clearly better. There is no significant hotspot
improvement according to perf report, as there are quite a few
callers of memcg_swap_enabled and do_memsw_account (which calls
memcg_swap_enabled). Many pieces of minor optimizations resulted
in lower overhead for the branch predictor, and bettter performance.
Link: https://lkml.kernel.org/r/20220919180634.45958-3-ryncsn@gmail.com
Signed-off-by: Kairui Song <kasong@tencent.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Muchun Song <songmuchun@bytedance.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Liu Shixin
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4988fe6952 |
mm/memcontrol: use kstrtobool for swapaccount param parsing
Use kstrtobool which is more powerful to handle all kinds of parameters like 'Yy1Nn0' or [oO][NnFf] for "on" and "off". Link: https://lkml.kernel.org/r/20220913071358.1812206-1-liushixin2@huawei.com Signed-off-by: Liu Shixin <liushixin2@huawei.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Shakeel Butt <shakeelb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Shakeel Butt
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8278f1c7b4 |
memcg: reduce size of memcg vmstats structures
The struct memcg_vmstats and struct memcg_vmstats_percpu contains two arrays each for events of size NR_VM_EVENT_ITEMS which can be as large as 110. However the memcg v1 only uses 4 of those while memcg v2 uses 15. The union of both is 17. On a 64 bit system, we are wasting approximately ((110 - 17) * 8 * 2) * (nr_cpus + 1) bytes which is significant on large machines. This patch reduces the size of the given structures by adding one indirection and only stores array of events which are actually used by the memcg code. With this patch, the size of memcg_vmstats has reduced from 2544 bytes to 1056 bytes while the size of memcg_vmstats_percpu has reduced from 2568 bytes to 1080 bytes. [akpm@linux-foundation.org: fix memcg_events_local() array index, per Shakeel] Link: https://lkml.kernel.org/r/CALvZod70Mvxr+Nzb6k0yiU2RFYjTD=0NFhKK-Eyp+5ejd1PSFw@mail.gmail.com Link: https://lkml.kernel.org/r/20220907043537.3457014-4-shakeelb@google.com Signed-off-by: Shakeel Butt <shakeelb@google.com> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Shakeel Butt
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d396def5d8 |
memcg: rearrange code
This is a preparatory patch for easing the review of the follow up patch which will reduce the memory overhead of memory cgroups. Link: https://lkml.kernel.org/r/20220907043537.3457014-3-shakeelb@google.com Signed-off-by: Shakeel Butt <shakeelb@google.com> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Shakeel Butt
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410f8e8268 |
memcg: extract memcg_vmstats from struct mem_cgroup
Patch series "memcg: reduce memory overhead of memory cgroups". Currently a lot of memory is wasted to maintain the vmevents for memory cgroups as we have multiple arrays of size NR_VM_EVENT_ITEMS which can be as large as 110. However memcg code uses small portion of those entries. This patch series eliminate this overhead by removing the unneeded vmevent entries from memory cgroup data structures. This patch (of 3): This is a preparatory patch to reduce the memory overhead of memory cgroup. The struct memcg_vmstats is the largest object embedded into the struct mem_cgroup. This patch extracts struct memcg_vmstats from struct mem_cgroup to ease the following patches in reducing the size of struct memcg_vmstats. Link: https://lkml.kernel.org/r/20220907043537.3457014-1-shakeelb@google.com Link: https://lkml.kernel.org/r/20220907043537.3457014-2-shakeelb@google.com Signed-off-by: Shakeel Butt <shakeelb@google.com> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Matthew Wilcox (Oracle)
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9202d527b7 |
memcg: convert mem_cgroup_swap_full() to take a folio
All callers now have a folio, so convert the function to take a folio. Saves a couple of calls to compound_head(). Link: https://lkml.kernel.org/r/20220902194653.1739778-48-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Matthew Wilcox (Oracle)
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cb691e2f28 |
mm: remove lookup_swap_cache()
All callers have now been converted to swap_cache_get_folio(), so we can remove this wrapper. Link: https://lkml.kernel.org/r/20220902194653.1739778-39-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |