diff options
| author | Marco Crivellari <marco.crivellari@suse.com> | 2025-06-14 15:35:30 +0200 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2025-06-17 08:52:09 -1000 |
| commit | 930c2ea566aff59e962c50b2421d5fcc3b98b8be (patch) | |
| tree | bc7851f564351e810bf3103ccd91876af6c4d5d6 | |
| parent | 128ea9f6ccfb6960293ae4212f4f97165e42222d (diff) | |
workqueue: Add new WQ_PERCPU flag
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.
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.
tj: Merged doc patch.
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
| -rw-r--r-- | Documentation/core-api/workqueue.rst | 6 | ||||
| -rw-r--r-- | include/linux/workqueue.h | 1 |
2 files changed, 7 insertions, 0 deletions
diff --git a/Documentation/core-api/workqueue.rst b/Documentation/core-api/workqueue.rst index e295835fc116..165ca73e8351 100644 --- a/Documentation/core-api/workqueue.rst +++ b/Documentation/core-api/workqueue.rst @@ -183,6 +183,12 @@ resources, scheduled and executed. BH work items cannot sleep. All other features such as delayed queueing, flushing and canceling are supported. +``WQ_PERCPU`` + Work items queued to a per-cpu wq are bound to a specific CPU. + This flag is the right choice when cpu locality is important. + + This flag is the complement of ``WQ_UNBOUND``. + ``WQ_UNBOUND`` Work items queued to an unbound wq are served by the special worker-pools which host workers which are not bound to any diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h index 74b0042709cd..f19072605faa 100644 --- a/include/linux/workqueue.h +++ b/include/linux/workqueue.h @@ -401,6 +401,7 @@ enum wq_flags { * http://thread.gmane.org/gmane.linux.kernel/1480396 */ WQ_POWER_EFFICIENT = 1 << 7, + WQ_PERCPU = 1 << 8, /* bound to a specific cpu */ __WQ_DESTROYING = 1 << 15, /* internal: workqueue is destroying */ __WQ_DRAINING = 1 << 16, /* internal: workqueue is draining */ |