From 7ee681b25284782ecf380bf5ccf55f13c52fd0ce Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 13 Jul 2016 17:16:29 +0000 Subject: workqueue: Convert to state machine callbacks Get rid of the prio ordering of the separate notifiers and use a proper state callback pair. Signed-off-by: Thomas Gleixner Signed-off-by: Anna-Maria Gleixner Reviewed-by: Sebastian Andrzej Siewior Acked-by: Tejun Heo Cc: Andrew Morton Cc: Lai Jiangshan Cc: Linus Torvalds Cc: Nicolas Iooss Cc: Oleg Nesterov Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Rasmus Villemoes Cc: Rusty Russell Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20160713153335.197083890@linutronix.de Signed-off-by: Ingo Molnar --- kernel/workqueue.c | 108 +++++++++++++++++++++-------------------------------- 1 file changed, 43 insertions(+), 65 deletions(-) (limited to 'kernel/workqueue.c') diff --git a/kernel/workqueue.c b/kernel/workqueue.c index e1c0e996b5ae..c9dd5fbdbf33 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -4611,84 +4611,65 @@ static void restore_unbound_workers_cpumask(struct worker_pool *pool, int cpu) pool->attrs->cpumask) < 0); } -/* - * Workqueues should be brought up before normal priority CPU notifiers. - * This will be registered high priority CPU notifier. - */ -static int workqueue_cpu_up_callback(struct notifier_block *nfb, - unsigned long action, - void *hcpu) +int workqueue_prepare_cpu(unsigned int cpu) +{ + struct worker_pool *pool; + + for_each_cpu_worker_pool(pool, cpu) { + if (pool->nr_workers) + continue; + if (!create_worker(pool)) + return -ENOMEM; + } + return 0; +} + +int workqueue_online_cpu(unsigned int cpu) { - int cpu = (unsigned long)hcpu; struct worker_pool *pool; struct workqueue_struct *wq; int pi; - switch (action & ~CPU_TASKS_FROZEN) { - case CPU_UP_PREPARE: - for_each_cpu_worker_pool(pool, cpu) { - if (pool->nr_workers) - continue; - if (!create_worker(pool)) - return NOTIFY_BAD; - } - break; - - case CPU_DOWN_FAILED: - case CPU_ONLINE: - mutex_lock(&wq_pool_mutex); + mutex_lock(&wq_pool_mutex); - for_each_pool(pool, pi) { - mutex_lock(&pool->attach_mutex); + for_each_pool(pool, pi) { + mutex_lock(&pool->attach_mutex); - if (pool->cpu == cpu) - rebind_workers(pool); - else if (pool->cpu < 0) - restore_unbound_workers_cpumask(pool, cpu); + if (pool->cpu == cpu) + rebind_workers(pool); + else if (pool->cpu < 0) + restore_unbound_workers_cpumask(pool, cpu); - mutex_unlock(&pool->attach_mutex); - } + mutex_unlock(&pool->attach_mutex); + } - /* update NUMA affinity of unbound workqueues */ - list_for_each_entry(wq, &workqueues, list) - wq_update_unbound_numa(wq, cpu, true); + /* update NUMA affinity of unbound workqueues */ + list_for_each_entry(wq, &workqueues, list) + wq_update_unbound_numa(wq, cpu, true); - mutex_unlock(&wq_pool_mutex); - break; - } - return NOTIFY_OK; + mutex_unlock(&wq_pool_mutex); + return 0; } -/* - * Workqueues should be brought down after normal priority CPU notifiers. - * This will be registered as low priority CPU notifier. - */ -static int workqueue_cpu_down_callback(struct notifier_block *nfb, - unsigned long action, - void *hcpu) +int workqueue_offline_cpu(unsigned int cpu) { - int cpu = (unsigned long)hcpu; struct work_struct unbind_work; struct workqueue_struct *wq; - switch (action & ~CPU_TASKS_FROZEN) { - case CPU_DOWN_PREPARE: - /* unbinding per-cpu workers should happen on the local CPU */ - INIT_WORK_ONSTACK(&unbind_work, wq_unbind_fn); - queue_work_on(cpu, system_highpri_wq, &unbind_work); - - /* update NUMA affinity of unbound workqueues */ - mutex_lock(&wq_pool_mutex); - list_for_each_entry(wq, &workqueues, list) - wq_update_unbound_numa(wq, cpu, false); - mutex_unlock(&wq_pool_mutex); - - /* wait for per-cpu unbinding to finish */ - flush_work(&unbind_work); - destroy_work_on_stack(&unbind_work); - break; - } - return NOTIFY_OK; + /* unbinding per-cpu workers should happen on the local CPU */ + INIT_WORK_ONSTACK(&unbind_work, wq_unbind_fn); + queue_work_on(cpu, system_highpri_wq, &unbind_work); + + /* update NUMA affinity of unbound workqueues */ + mutex_lock(&wq_pool_mutex); + list_for_each_entry(wq, &workqueues, list) + wq_update_unbound_numa(wq, cpu, false); + mutex_unlock(&wq_pool_mutex); + + /* wait for per-cpu unbinding to finish */ + flush_work(&unbind_work); + destroy_work_on_stack(&unbind_work); + return 0; } #ifdef CONFIG_SMP @@ -5490,9 +5471,6 @@ static int __init init_workqueues(void) pwq_cache = KMEM_CACHE(pool_workqueue, SLAB_PANIC); - cpu_notifier(workqueue_cpu_up_callback, CPU_PRI_WORKQUEUE_UP); - hotcpu_notifier(workqueue_cpu_down_callback, CPU_PRI_WORKQUEUE_DOWN); - wq_numa_init(); /* initialize CPU pools */ -- cgit