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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.

Tejun Heo committed 13 years ago

Commit 35b6bb61 parent 24647571 file · +15 −13Browse files

Showing the changes to kernel/workqueue.c (1 of 1 file). Show all

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kernel/workqueue.c+15−13
@@ -46,11 +46,6 @@ · 45 unmodified lines
46#include "workqueue_internal.h"46#include "workqueue_internal.h"
47 47
48enum {48enum {
49 /*
50 * global_cwq flags
51 */
52 GCWQ_FREEZING = 1 << 1, /* freeze in progress */
53
54 /*49 /*
55 * worker_pool flags50 * worker_pool flags
56 *51 *
@@ -70,6 +65,7 @@ enum { · 13 unmodified lines
70 POOL_MANAGE_WORKERS = 1 << 0, /* need to manage workers */65 POOL_MANAGE_WORKERS = 1 << 0, /* need to manage workers */
71 POOL_MANAGING_WORKERS = 1 << 1, /* managing workers */66 POOL_MANAGING_WORKERS = 1 << 1, /* managing workers */
72 POOL_DISASSOCIATED = 1 << 2, /* cpu can't serve workers */67 POOL_DISASSOCIATED = 1 << 2, /* cpu can't serve workers */
68 POOL_FREEZING = 1 << 3, /* freeze in progress */
73 69
74 /* worker flags */70 /* worker flags */
75 WORKER_STARTED = 1 << 0, /* started */71 WORKER_STARTED = 1 << 0, /* started */
@@ -152,7 +148,6 @@ struct worker_pool { · 76 unmodified lines
152struct global_cwq {148struct global_cwq {
153 spinlock_t lock; /* the gcwq lock */149 spinlock_t lock; /* the gcwq lock */
154 unsigned int cpu; /* I: the associated cpu */150 unsigned int cpu; /* I: the associated cpu */
155 unsigned int flags; /* L: GCWQ_* flags */
156 151
157 /* workers are chained either in busy_hash or pool idle_list */152 /* workers are chained either in busy_hash or pool idle_list */
158 DECLARE_HASHTABLE(busy_hash, BUSY_WORKER_HASH_ORDER);153 DECLARE_HASHTABLE(busy_hash, BUSY_WORKER_HASH_ORDER);
@@ -3380,13 +3375,15 @@ void workqueue_set_max_active(struct workqueue_struct *wq, int max_active) · 3221 unmodified lines
3380 wq->saved_max_active = max_active;3375 wq->saved_max_active = max_active;
3381 3376
3382 for_each_cwq_cpu(cpu, wq) {3377 for_each_cwq_cpu(cpu, wq) {
3383 struct global_cwq *gcwq = get_gcwq(cpu);3378 struct cpu_workqueue_struct *cwq = get_cwq(cpu, wq);
3379 struct worker_pool *pool = cwq->pool;
3380 struct global_cwq *gcwq = pool->gcwq;
3384 3381
3385 spin_lock_irq(&gcwq->lock);3382 spin_lock_irq(&gcwq->lock);
3386 3383
3387 if (!(wq->flags & WQ_FREEZABLE) ||3384 if (!(wq->flags & WQ_FREEZABLE) ||
3388 !(gcwq->flags & GCWQ_FREEZING))3385 !(pool->flags & POOL_FREEZING))
3389 cwq_set_max_active(get_cwq(gcwq->cpu, wq), max_active);3386 cwq_set_max_active(cwq, max_active);
3390 3387
3391 spin_unlock_irq(&gcwq->lock);3388 spin_unlock_irq(&gcwq->lock);
3392 }3389 }
@@ -3676,12 +3673,15 @@ void freeze_workqueues_begin(void) · 283 unmodified lines
3676 3673
3677 for_each_gcwq_cpu(cpu) {3674 for_each_gcwq_cpu(cpu) {
3678 struct global_cwq *gcwq = get_gcwq(cpu);3675 struct global_cwq *gcwq = get_gcwq(cpu);
3676 struct worker_pool *pool;
3679 struct workqueue_struct *wq;3677 struct workqueue_struct *wq;
3680 3678
3681 spin_lock_irq(&gcwq->lock);3679 spin_lock_irq(&gcwq->lock);
3682 3680
3683 BUG_ON(gcwq->flags & GCWQ_FREEZING);3681 for_each_worker_pool(pool, gcwq) {
3684 gcwq->flags |= GCWQ_FREEZING;3682 WARN_ON_ONCE(pool->flags & POOL_FREEZING);
3683 pool->flags |= POOL_FREEZING;
3684 }
3685 3685
3686 list_for_each_entry(wq, &workqueues, list) {3686 list_for_each_entry(wq, &workqueues, list) {
3687 struct cpu_workqueue_struct *cwq = get_cwq(cpu, wq);3687 struct cpu_workqueue_struct *cwq = get_cwq(cpu, wq);
@@ -3767,8 +3767,10 @@ void thaw_workqueues(void) · 79 unmodified lines
3767 3767
3768 spin_lock_irq(&gcwq->lock);3768 spin_lock_irq(&gcwq->lock);
3769 3769
3770 BUG_ON(!(gcwq->flags & GCWQ_FREEZING));3770 for_each_worker_pool(pool, gcwq) {
3771 gcwq->flags &= ~GCWQ_FREEZING;3771 WARN_ON_ONCE(!(pool->flags & POOL_FREEZING));
3772 pool->flags &= ~POOL_FREEZING;
3773 }
3772 3774
3773 list_for_each_entry(wq, &workqueues, list) {3775 list_for_each_entry(wq, &workqueues, list) {
3774 struct cpu_workqueue_struct *cwq = get_cwq(cpu, wq);3776 struct cpu_workqueue_struct *cwq = get_cwq(cpu, wq);