From: Marco Crivellari Date: Fri, 29 May 2026 13:06:39 +0000 (+0200) Subject: workqueue: Add warnings and fallback if system_{unbound}_wq is used X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=64d8eae3f89583821f599c0aa398dd2e69b31a89;p=thirdparty%2Fkernel%2Flinux.git workqueue: Add warnings and fallback if system_{unbound}_wq is used Currently many users transitioned already to the new introduced workqueue (system_percpu_wq, system_dfl_wq), but there are new users who still use the older system_wq and system_unbound_wq. This change try to push this transition forward, by warning whether the old workqueues are used. Link: https://lore.kernel.org/all/20250221112003.1dSuoGyc@linutronix.de/ Suggested-by: Tejun Heo Signed-off-by: Marco Crivellari Signed-off-by: Tejun Heo --- diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h index 6177624539b3b..a283766a192aa 100644 --- a/include/linux/workqueue.h +++ b/include/linux/workqueue.h @@ -409,6 +409,7 @@ enum wq_flags { __WQ_DRAINING = 1 << 16, /* internal: workqueue is draining */ __WQ_ORDERED = 1 << 17, /* internal: workqueue is ordered */ __WQ_LEGACY = 1 << 18, /* internal: create*_workqueue() */ + __WQ_DEPRECATED = 1 << 19, /* internal: workqueue is deprecated */ /* BH wq only allows the following flags */ __WQ_BH_ALLOWS = WQ_BH | WQ_HIGHPRI | WQ_PERCPU, diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 35b0c8f4f10f2..088cd9b70fca3 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -2280,6 +2280,14 @@ static void __queue_work(int cpu, struct workqueue_struct *wq, unsigned int work_flags; unsigned int req_cpu = cpu; + /* + * NOTE: Check whether the used workqueue is deprecated and warn + */ + if (unlikely(wq->flags & __WQ_DEPRECATED)) + pr_warn_once("workqueue: work func %ps enqueued on deprecated workqueue. " + "Use system_{percpu|dfl}_wq instead.\n", + work->func); + /* * While a work item is PENDING && off queue, a task trying to * steal the PENDING will busy-loop waiting for it to either get @@ -8013,12 +8021,12 @@ void __init workqueue_init_early(void) ordered_wq_attrs[i] = attrs; } - system_wq = alloc_workqueue("events", WQ_PERCPU, 0); + system_wq = alloc_workqueue("events", WQ_PERCPU | __WQ_DEPRECATED, 0); system_percpu_wq = alloc_workqueue("events", WQ_PERCPU, 0); system_highpri_wq = alloc_workqueue("events_highpri", WQ_HIGHPRI | WQ_PERCPU, 0); system_long_wq = alloc_workqueue("events_long", WQ_PERCPU, 0); - system_unbound_wq = alloc_workqueue("events_unbound", WQ_UNBOUND, WQ_MAX_ACTIVE); + system_unbound_wq = alloc_workqueue("events_unbound", WQ_UNBOUND | __WQ_DEPRECATED, WQ_MAX_ACTIVE); system_dfl_wq = alloc_workqueue("events_unbound", WQ_UNBOUND, WQ_MAX_ACTIVE); system_freezable_wq = alloc_workqueue("events_freezable", WQ_FREEZABLE | WQ_PERCPU, 0);