On Fri, Sep 05, 2025 at 10:57:01AM +0200, Marco Crivellari wrote: > 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@xxxxxxxxxx> > Signed-off-by: Marco Crivellari <marco.crivellari@xxxxxxxx> > --- > crypto/cryptd.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) Patch applied. Thanks. -- Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
