From 1ad5dcee7c819031cf02eaf5e1e03728d0ffeb09 Mon Sep 17 00:00:00 2001 From: Breno Leitao Date: Fri, 26 Jun 2026 02:57:53 -0700 Subject: workqueue: split kick_pool() into kick_pool_pick() Factor the worker selection out of kick_pool() into kick_pool_pick(), which picks and claims the worker under pool->lock but, instead of waking it, returns the worker's task via an out-param so the caller can issue the wakeup after dropping pool->lock. BH kicks and wake_cpu setup still happen under the lock. kick_pool() becomes a thin wrapper that wakes the returned task, so all existing callers keep waking under pool->lock. Pure refactor, no functional change. Signed-off-by: Breno Leitao Signed-off-by: Tejun Heo --- kernel/workqueue.c | 35 ++++++++++++++++++++++++++++++----- 1 file changed, 30 insertions(+), 5 deletions(-) (limited to 'kernel/workqueue.c') diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 78068ae8f28a..49770093e785 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -1258,19 +1258,27 @@ static void kick_bh_pool(struct worker_pool *pool) } /** - * kick_pool - wake up an idle worker if necessary + * kick_pool_pick - select an idle worker to kick, deferring the wakeup * @pool: pool to kick + * @wakep: out-param, set to the task to wake after pool->lock is dropped * - * @pool may have pending work items. Wake up worker if necessary. Returns - * whether a worker was woken up. + * Like kick_pool() but, for a regular (non-BH) pool, returns the picked + * worker's task via @wakep instead of waking it, so the caller can issue the + * wakeup after dropping pool->lock (the wakeup takes rq->lock). Worker + * selection, wake_cpu setup and the BH kick still happen under the lock. + * Returns whether a worker was selected or kicked. + * + * Must be called with @pool->lock held. */ -static bool kick_pool(struct worker_pool *pool) +static bool kick_pool_pick(struct worker_pool *pool, struct task_struct **wakep) { struct worker *worker = first_idle_worker(pool); struct task_struct *p; lockdep_assert_held(&pool->lock); + *wakep = NULL; + if (!need_more_worker(pool) || !worker) return false; @@ -1310,10 +1318,27 @@ static bool kick_pool(struct worker_pool *pool) } } #endif - wake_up_process(p); + *wakep = p; return true; } +/** + * kick_pool - wake up an idle worker if necessary + * @pool: pool to kick + * + * @pool may have pending work items. Wake up worker if necessary. Returns + * whether a worker was woken up. + */ +static bool kick_pool(struct worker_pool *pool) +{ + struct task_struct *p; + bool kicked = kick_pool_pick(pool, &p); + + if (p) + wake_up_process(p); + return kicked; +} + #ifdef CONFIG_WQ_CPU_INTENSIVE_REPORT /* -- cgit v1.2.3