linux/Documentation/core-api
Linus Torvalds bd30fe6a7d workqueue: Changes for v6.6
* Unbound workqueues now support more flexible affinity scopes. The default
   behavior is to soft-affine according to last level cache boundaries. A
   work item queued from a given LLC is executed by a worker running on the
   same LLC but the worker may be moved across cache boundaries as the
   scheduler sees fit. On machines which multiple L3 caches, which are
   becoming more popular along with chiplet designs, this improves cache
   locality while not harming work conservation too much.
 
   Unbound workqueues are now also a lot more flexible in terms of execution
   affinity. Differeing levels of affinity scopes are supported and both the
   default and per-workqueue affinity settings can be modified dynamically.
   This should help working around amny of sub-optimal behaviors observed
   recently with asymmetric ARM CPUs.
 
   This involved signficant restructuring of workqueue code. Nothing was
   reported yet but there's some risk of subtle regressions. Should keep an
   eye out.
 
 * Rescuer workers now has more identifiable comms.
 
 * workqueue.unbound_cpus added so that CPUs which can be used by workqueue
   can be constrained early during boot.
 
 * Now that all the in-tree users have been flushed out, trigger warning if
   system-wide workqueues are flushed.
 
 * One pull commit from for-6.5-fixes to avoid cascading conflicts in the
   affinity scope patchset.
 -----BEGIN PGP SIGNATURE-----
 
 iIQEABYIACwWIQTfIjM1kS57o3GsC/uxYfJx3gVYGQUCZPERlQ4cdGpAa2VybmVs
 Lm9yZwAKCRCxYfJx3gVYGVqQAPwIOy9tWY5jFAmMuIyH6wV50hbmfxCc2n5xhQNr
 5HoyGgEA8lw1W7afDCIPiQVA7AYsu8dhwuNSOcRCJxhrrn4XsA0=
 =g/Uu
 -----END PGP SIGNATURE-----

Merge tag 'wq-for-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq

Pull workqueue updates from Tejun Heo:

 - Unbound workqueues now support more flexible affinity scopes.

   The default behavior is to soft-affine according to last level cache
   boundaries. A work item queued from a given LLC is executed by a
   worker running on the same LLC but the worker may be moved across
   cache boundaries as the scheduler sees fit. On machines which
   multiple L3 caches, which are becoming more popular along with
   chiplet designs, this improves cache locality while not harming work
   conservation too much.

   Unbound workqueues are now also a lot more flexible in terms of
   execution affinity. Differeing levels of affinity scopes are
   supported and both the default and per-workqueue affinity settings
   can be modified dynamically. This should help working around amny of
   sub-optimal behaviors observed recently with asymmetric ARM CPUs.

   This involved signficant restructuring of workqueue code. Nothing was
   reported yet but there's some risk of subtle regressions. Should keep
   an eye out.

 - Rescuer workers now has more identifiable comms.

 - workqueue.unbound_cpus added so that CPUs which can be used by
   workqueue can be constrained early during boot.

 - Now that all the in-tree users have been flushed out, trigger warning
   if system-wide workqueues are flushed.

* tag 'wq-for-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (31 commits)
  workqueue: fix data race with the pwq->stats[] increment
  workqueue: Rename rescuer kworker
  workqueue: Make default affinity_scope dynamically updatable
  workqueue: Add "Affinity Scopes and Performance" section to documentation
  workqueue: Implement non-strict affinity scope for unbound workqueues
  workqueue: Add workqueue_attrs->__pod_cpumask
  workqueue: Factor out need_more_worker() check and worker wake-up
  workqueue: Factor out work to worker assignment and collision handling
  workqueue: Add multiple affinity scopes and interface to select them
  workqueue: Modularize wq_pod_type initialization
  workqueue: Add tools/workqueue/wq_dump.py which prints out workqueue configuration
  workqueue: Generalize unbound CPU pods
  workqueue: Factor out clearing of workqueue-only attrs fields
  workqueue: Factor out actual cpumask calculation to reduce subtlety in wq_update_pod()
  workqueue: Initialize unbound CPU pods later in the boot
  workqueue: Move wq_pod_init() below workqueue_init()
  workqueue: Rename NUMA related names to use pod instead
  workqueue: Rename workqueue_attrs->no_numa to ->ordered
  workqueue: Make unbound workqueues to use per-cpu pool_workqueues
  workqueue: Call wq_update_unbound_numa() on all CPUs in NUMA node on CPU hotplug
  ...
2023-09-01 16:06:32 -07:00
..
irq Documentation: irqdomain: Fix typo of "at least once" 2022-08-18 11:11:52 -06:00
wrappers docs: put atomic*.txt and memory-barriers.txt into the core-api book 2022-09-29 12:55:06 -06:00
asm-annotations.rst docs: move x86 documentation into Documentation/arch/ 2023-03-30 12:58:51 -06:00
assoc_array.rst
boot-time-mm.rst
cachetlb.rst mm: remove ARCH_IMPLEMENTS_FLUSH_DCACHE_FOLIO 2023-08-24 16:20:19 -07:00
circular-buffers.rst
cpu_hotplug.rst - An extensive rework of kexec and crash Kconfig from Eric DeVolder 2023-08-29 14:53:51 -07:00
debug-objects.rst
debugging-via-ohci1394.rst
dma-api-howto.rst dma-api-howto: typo fix 2023-04-10 16:46:11 -06:00
dma-api.rst docs/mm: Physical Memory: remove useless markup 2023-02-02 10:18:04 -07:00
dma-attributes.rst Reinstate some of "swiotlb: rework "fix info leak with DMA_FROM_DEVICE"" 2022-03-28 11:37:05 -07:00
dma-isa-lpc.rst docs: core-api: avoid using ReST :doc:`foo` markup 2021-06-17 13:24:37 -06:00
entry.rst Documentation: core-api: entry: Add comments about nesting 2022-01-27 11:32:40 -07:00
errseq.rst
genalloc.rst
generic-radix-tree.rst
genericirq.rst Docu: genericirq.rst: fix irq-example 2023-08-28 12:45:31 -06:00
gfp_mask-from-fs-io.rst
idr.rst IDR: Note that the IDR API is deprecated 2022-07-10 21:17:30 -04:00
index.rst docs: add more netlink docs (incl. spec docs) 2023-01-24 10:58:11 +01:00
kernel-api.rst Documentation: core-api: Drop :export: for int_log.h 2023-07-25 17:40:25 +01:00
kobject.rst kobject documentation: remove default_attrs information 2022-01-07 11:23:37 +01:00
kref.rst
librs.rst
local_ops.rst timers: Update the documentation to reflect on the new timer_shutdown() API 2022-11-24 15:09:12 +01:00
maple_tree.rst Maple Tree: add new data structure 2022-09-26 19:46:13 -07:00
memory-allocation.rst mm/slab: document kfree() as allowed for kmem_cache_alloc() objects 2023-03-29 10:35:41 +02:00
memory-hotplug.rst mm/memory_hotplug: remove HIGHMEM leftovers 2021-11-06 13:30:42 -07:00
mm-api.rst mm: add orphaned kernel-doc to the rst files. 2023-08-24 16:20:31 -07:00
netlink.rst doc/netlink: Update genetlink-legacy documentation 2023-08-27 17:17:09 -07:00
packing.rst Documentation: core-api: packing: correct spelling 2023-02-15 21:40:54 -08:00
padata.rst Documentation: core-api: padata: correct spelling 2023-02-16 16:58:01 -07:00
pin_user_pages.rst mm: Don't pin ZERO_PAGE in pin_user_pages() 2023-05-31 09:48:15 -06:00
printk-basics.rst printk: Move the printk() kerneldoc comment to its new home 2021-07-26 12:36:44 +02:00
printk-formats.rst mm, printk: introduce new format %pGt for page_type 2023-03-28 16:20:09 -07:00
printk-index.rst printk/index: Printk index feature documentation 2022-04-13 14:25:31 +02:00
protection-keys.rst Documentation/protection-keys: Clean up documentation for User Space pkeys 2022-06-07 16:06:22 -07:00
rbtree.rst docs: rbtree.rst: Fix a typo 2021-03-25 11:38:51 -06:00
refcount-vs-atomic.rst
symbol-namespaces.rst doc: module: update file references 2022-07-01 14:50:01 -07:00
this_cpu_ops.rst arch: Remove cmpxchg_double 2023-06-05 09:36:39 +02:00
timekeeping.rst timekeeping: Introduce fast accessor to clock tai 2022-04-14 16:19:30 +02:00
tracepoint.rst
unaligned-memory-access.rst
watch_queue.rst Documentation: move watch_queue to core-api 2022-04-22 09:47:25 -06:00
workqueue.rst workqueue: Make default affinity_scope dynamically updatable 2023-08-07 15:57:25 -10:00
xarray.rst XArray: Document the locking requirement for the xa_state 2022-02-03 15:56:50 -05:00