mirror of https://github.com/torvalds/linux.git
4fcd322914
Currently if a user enqueue a work item using schedule_delayed_work() the used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to schedule_work() that is using system_wq and queue_work(), that makes use again of WORK_CPU_UNBOUND. This lack of consistentcy cannot be addressed without refactoring the API. alloc_workqueue() treats all queues as per-CPU by default, while unbound workqueues must opt-in via WQ_UNBOUND. This default is suboptimal: most workloads benefit from unbound queues, allowing the scheduler to place worker threads where they’re needed and reducing noise when CPUs are isolated. This default is suboptimal: most workloads benefit from unbound queues, allowing the scheduler to place worker threads where they’re needed and reducing noise when CPUs are isolated. This patch adds a new WQ_PERCPU flag to explicitly request the use of the per-CPU behavior. Both flags coexist for one release cycle to allow callers to transition their calls. Once migration is complete, WQ_UNBOUND can be removed and unbound will become the implicit default. With the introduction of the WQ_PERCPU flag (equivalent to !WQ_UNBOUND), any alloc_workqueue() caller that doesn’t explicitly specify WQ_UNBOUND must now use WQ_PERCPU. All existing users have been updated accordingly. Suggested-by: Tejun Heo <tj@kernel.org> Signed-off-by: Marco Crivellari <marco.crivellari@suse.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> |
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| cgroup | ||
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| debug | ||
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| entry | ||
| events | ||
| futex | ||
| gcov | ||
| irq | ||
| kcsan | ||
| livepatch | ||
| locking | ||
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| power | ||
| printk | ||
| rcu | ||
| sched | ||
| time | ||
| trace | ||
| unwind | ||
| .gitignore | ||
| Kconfig.freezer | ||
| Kconfig.hz | ||
| Kconfig.kexec | ||
| Kconfig.locks | ||
| Kconfig.preempt | ||
| Makefile | ||
| acct.c | ||
| async.c | ||
| audit.c | ||
| audit.h | ||
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| capability.c | ||
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| configs.c | ||
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| cpu.c | ||
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| crash_dump_dm_crypt.c | ||
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| cred.c | ||
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| gen_kheaders.sh | ||
| groups.c | ||
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| irq_work.c | ||
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| stacktrace.c | ||
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| stop_machine.c | ||
| sys.c | ||
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| sysctl-test.c | ||
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| task_work.c | ||
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| workqueue.c | ||
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