diff options
| author | Marco Crivellari <marco.crivellari@suse.com> | 2025-09-05 10:57:01 +0200 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2025-09-13 12:11:06 +0800 |
| commit | a5d71f011ee1f211e437333555fd981e040c146c (patch) | |
| tree | 46e0128475406bb6ec356bd6b784eecba1548dd7 | |
| parent | 9c6ed103a75756aadee0e4e6a1aa3b8187b55c22 (diff) | |
crypto: cryptd - WQ_PERCPU added to alloc_workqueue users
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>
| -rw-r--r-- | crypto/cryptd.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/crypto/cryptd.c b/crypto/cryptd.c index efff54e707cb..cd38f4676176 100644 --- a/crypto/cryptd.c +++ b/crypto/cryptd.c @@ -1115,7 +1115,8 @@ static int __init cryptd_init(void) { int err; - cryptd_wq = alloc_workqueue("cryptd", WQ_MEM_RECLAIM | WQ_CPU_INTENSIVE, + cryptd_wq = alloc_workqueue("cryptd", + WQ_MEM_RECLAIM | WQ_CPU_INTENSIVE | WQ_PERCPU, 1); if (!cryptd_wq) return -ENOMEM; |