From 403c821d452c03be4ced571ac91339a9d3631b17 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 17 Jul 2012 12:39:27 -0700 Subject: [PATCH] workqueue: ROGUE workers are UNBOUND workers Currently, WORKER_UNBOUND is used to mark workers for the unbound global_cwq and WORKER_ROGUE is used to mark workers for disassociated per-cpu global_cwqs. Both are used to make the marked worker skip concurrency management and the only place they make any difference is in worker_enter_idle() where WORKER_ROGUE is used to skip scheduling idle timer, which can easily be replaced with trustee state testing. This patch replaces WORKER_ROGUE with WORKER_UNBOUND and drops WORKER_ROGUE. This is to prepare for removing trustee and handling disassociated global_cwqs as unbound. Signed-off-by: Tejun Heo Acked-by: "Rafael J. Wysocki" --- kernel/workqueue.c | 46 +++++++++++++++++++++------------------------- 1 file changed, 21 insertions(+), 25 deletions(-) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 1405fb9..af51292 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -58,13 +58,12 @@ enum { WORKER_DIE = 1 << 1, /* die die die */ WORKER_IDLE = 1 << 2, /* is idle */ WORKER_PREP = 1 << 3, /* preparing to run works */ - WORKER_ROGUE = 1 << 4, /* not bound to any cpu */ WORKER_REBIND = 1 << 5, /* mom is home, come back */ WORKER_CPU_INTENSIVE = 1 << 6, /* cpu intensive */ WORKER_UNBOUND = 1 << 7, /* worker is unbound */ - WORKER_NOT_RUNNING = WORKER_PREP | WORKER_ROGUE | WORKER_REBIND | - WORKER_CPU_INTENSIVE | WORKER_UNBOUND, + WORKER_NOT_RUNNING = WORKER_PREP | WORKER_REBIND | WORKER_UNBOUND | + WORKER_CPU_INTENSIVE, /* gcwq->trustee_state */ TRUSTEE_START = 0, /* start */ @@ -1198,7 +1197,7 @@ static void worker_enter_idle(struct worker *worker) /* idle_list is LIFO */ list_add(&worker->entry, &pool->idle_list); - if (likely(!(worker->flags & WORKER_ROGUE))) { + if (likely(gcwq->trustee_state != TRUSTEE_DONE)) { if (too_many_workers(pool) && !timer_pending(&pool->idle_timer)) mod_timer(&pool->idle_timer, jiffies + IDLE_WORKER_TIMEOUT); @@ -1207,7 +1206,7 @@ static void worker_enter_idle(struct worker *worker) /* * Sanity check nr_running. Because trustee releases gcwq->lock - * between setting %WORKER_ROGUE and zapping nr_running, the + * between setting %WORKER_UNBOUND and zapping nr_running, the * warning may trigger spuriously. Check iff trustee is idle. */ WARN_ON_ONCE(gcwq->trustee_state == TRUSTEE_DONE && @@ -1301,10 +1300,10 @@ __acquires(&gcwq->lock) } /* - * Function for worker->rebind_work used to rebind rogue busy workers - * to the associated cpu which is coming back online. This is - * scheduled by cpu up but can race with other cpu hotplug operations - * and may be executed twice without intervening cpu down. + * Function for worker->rebind_work used to rebind unbound busy workers to + * the associated cpu which is coming back online. This is scheduled by + * cpu up but can race with other cpu hotplug operations and may be + * executed twice without intervening cpu down. */ static void worker_rebind_fn(struct work_struct *work) { @@ -1385,9 +1384,8 @@ static struct worker *create_worker(struct worker_pool *pool, bool bind) set_user_nice(worker->task, HIGHPRI_NICE_LEVEL); /* - * A rogue worker will become a regular one if CPU comes - * online later on. Make sure every worker has - * PF_THREAD_BOUND set. + * An unbound worker will become a regular one if CPU comes online + * later on. Make sure every worker has PF_THREAD_BOUND set. */ if (bind && !on_unbound_cpu) kthread_bind(worker->task, gcwq->cpu); @@ -3215,11 +3213,10 @@ EXPORT_SYMBOL_GPL(work_busy); * gcwqs serve mix of short, long and very long running works making * blocked draining impractical. * - * This is solved by allowing a gcwq to be detached from CPU, running - * it with unbound (rogue) workers and allowing it to be reattached - * later if the cpu comes back online. A separate thread is created - * to govern a gcwq in such state and is called the trustee of the - * gcwq. + * This is solved by allowing a gcwq to be detached from CPU, running it + * with unbound workers and allowing it to be reattached later if the cpu + * comes back online. A separate thread is created to govern a gcwq in + * such state and is called the trustee of the gcwq. * * Trustee states and their descriptions. * @@ -3359,19 +3356,18 @@ static int __cpuinit trustee_thread(void *__gcwq) pool->flags |= POOL_MANAGING_WORKERS; list_for_each_entry(worker, &pool->idle_list, entry) - worker->flags |= WORKER_ROGUE; + worker->flags |= WORKER_UNBOUND; } for_each_busy_worker(worker, i, pos, gcwq) - worker->flags |= WORKER_ROGUE; + worker->flags |= WORKER_UNBOUND; gcwq->flags |= GCWQ_DISASSOCIATED; /* - * Call schedule() so that we cross rq->lock and thus can - * guarantee sched callbacks see the rogue flag. This is - * necessary as scheduler callbacks may be invoked from other - * cpus. + * Call schedule() so that we cross rq->lock and thus can guarantee + * sched callbacks see the unbound flag. This is necessary as + * scheduler callbacks may be invoked from other cpus. */ spin_unlock_irq(&gcwq->lock); schedule(); @@ -3439,7 +3435,7 @@ static int __cpuinit trustee_thread(void *__gcwq) worker = create_worker(pool, false); spin_lock_irq(&gcwq->lock); if (worker) { - worker->flags |= WORKER_ROGUE; + worker->flags |= WORKER_UNBOUND; start_worker(worker); } } @@ -3488,7 +3484,7 @@ static int __cpuinit trustee_thread(void *__gcwq) * rebinding is scheduled. */ worker->flags |= WORKER_REBIND; - worker->flags &= ~WORKER_ROGUE; + worker->flags &= ~WORKER_UNBOUND; /* queue rebind_work, wq doesn't matter, use the default one */ if (test_and_set_bit(WORK_STRUCT_PENDING_BIT, -- 2.7.4