From 35b6bb63b8a288f90e07948867941a553b3d97bc Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 24 Jan 2013 11:01:33 -0800 Subject: [PATCH] workqueue: make GCWQ_FREEZING a pool flag Make GCWQ_FREEZING a pool flag POOL_FREEZING. This patch doesn't change locking - FREEZING on both pools of a CPU are set or clear together while holding gcwq->lock. It shouldn't cause any functional difference. This leaves gcwq->flags w/o any flags. Removed. While at it, convert BUG_ON()s in freeze_workqueue_begin() and thaw_workqueues() to WARN_ON_ONCE(). This is part of an effort to remove global_cwq and make worker_pool the top level abstraction, which in turn will help implementing worker pools with user-specified attributes. Signed-off-by: Tejun Heo Reviewed-by: Lai Jiangshan --- kernel/workqueue.c | 28 +++++++++++++++------------- 1 file changed, 15 insertions(+), 13 deletions(-) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 1b8af92cc2c9..1a686e481132 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -46,11 +46,6 @@ #include "workqueue_internal.h" enum { - /* - * global_cwq flags - */ - GCWQ_FREEZING = 1 << 1, /* freeze in progress */ - /* * worker_pool flags * @@ -70,6 +65,7 @@ enum { POOL_MANAGE_WORKERS = 1 << 0, /* need to manage workers */ POOL_MANAGING_WORKERS = 1 << 1, /* managing workers */ POOL_DISASSOCIATED = 1 << 2, /* cpu can't serve workers */ + POOL_FREEZING = 1 << 3, /* freeze in progress */ /* worker flags */ WORKER_STARTED = 1 << 0, /* started */ @@ -152,7 +148,6 @@ struct worker_pool { struct global_cwq { spinlock_t lock; /* the gcwq lock */ unsigned int cpu; /* I: the associated cpu */ - unsigned int flags; /* L: GCWQ_* flags */ /* workers are chained either in busy_hash or pool idle_list */ DECLARE_HASHTABLE(busy_hash, BUSY_WORKER_HASH_ORDER); @@ -3380,13 +3375,15 @@ void workqueue_set_max_active(struct workqueue_struct *wq, int max_active) wq->saved_max_active = max_active; for_each_cwq_cpu(cpu, wq) { - struct global_cwq *gcwq = get_gcwq(cpu); + struct cpu_workqueue_struct *cwq = get_cwq(cpu, wq); + struct worker_pool *pool = cwq->pool; + struct global_cwq *gcwq = pool->gcwq; spin_lock_irq(&gcwq->lock); if (!(wq->flags & WQ_FREEZABLE) || - !(gcwq->flags & GCWQ_FREEZING)) - cwq_set_max_active(get_cwq(gcwq->cpu, wq), max_active); + !(pool->flags & POOL_FREEZING)) + cwq_set_max_active(cwq, max_active); spin_unlock_irq(&gcwq->lock); } @@ -3676,12 +3673,15 @@ void freeze_workqueues_begin(void) for_each_gcwq_cpu(cpu) { struct global_cwq *gcwq = get_gcwq(cpu); + struct worker_pool *pool; struct workqueue_struct *wq; spin_lock_irq(&gcwq->lock); - BUG_ON(gcwq->flags & GCWQ_FREEZING); - gcwq->flags |= GCWQ_FREEZING; + for_each_worker_pool(pool, gcwq) { + WARN_ON_ONCE(pool->flags & POOL_FREEZING); + pool->flags |= POOL_FREEZING; + } list_for_each_entry(wq, &workqueues, list) { struct cpu_workqueue_struct *cwq = get_cwq(cpu, wq); @@ -3767,8 +3767,10 @@ void thaw_workqueues(void) spin_lock_irq(&gcwq->lock); - BUG_ON(!(gcwq->flags & GCWQ_FREEZING)); - gcwq->flags &= ~GCWQ_FREEZING; + for_each_worker_pool(pool, gcwq) { + WARN_ON_ONCE(!(pool->flags & POOL_FREEZING)); + pool->flags &= ~POOL_FREEZING; + } list_for_each_entry(wq, &workqueues, list) { struct cpu_workqueue_struct *cwq = get_cwq(cpu, wq);