From 27ce71e1ce81875df72f7698ba27988392bef602 Mon Sep 17 00:00:00 2001 From: Marco Crivellari Date: Thu, 18 Sep 2025 16:24:27 +0200 Subject: net: WQ_PERCPU added to alloc_workqueue users MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 change adds a new WQ_PERCPU flag at the network subsystem, 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 Signed-off-by: Marco Crivellari Link: https://patch.msgid.link/20250918142427.309519-4-marco.crivellari@suse.com Signed-off-by: Jakub Kicinski --- net/rxrpc/rxperf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/rxrpc') diff --git a/net/rxrpc/rxperf.c b/net/rxrpc/rxperf.c index 0377301156b0..2ea71e3831f7 100644 --- a/net/rxrpc/rxperf.c +++ b/net/rxrpc/rxperf.c @@ -630,7 +630,7 @@ static int __init rxperf_init(void) pr_info("Server registering\n"); - rxperf_workqueue = alloc_workqueue("rxperf", 0, 0); + rxperf_workqueue = alloc_workqueue("rxperf", WQ_PERCPU, 0); if (!rxperf_workqueue) goto error_workqueue; -- cgit v1.2.3