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 <tj@kernel.org>
Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com>
This commit is contained in:
Tejun Heo 2013-01-24 11:01:33 -08:00
parent 2464757086
commit 35b6bb63b8

View file

@ -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);