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workqueue: Convert the type of pool->nr_running to int

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It is only modified in associated CPU, so it doesn't need to be atomic.

tj: Comment updated.

Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
This commit is contained in:
Lai Jiangshan
2021-12-23 20:31:40 +08:00
committed by Tejun Heo
parent cc5bff3846
commit bc35f7ef96
1 changed files with 16 additions and 13 deletions
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29
kernel/workqueue.c
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@ -154,8 +154,13 @@ struct worker_pool {
unsigned long watchdog_ts; /* L: watchdog timestamp */ unsigned long watchdog_ts; /* L: watchdog timestamp */
/* The current concurrency level. */ /*
atomic_t nr_running; * The counter is incremented in a process context on the associated CPU
* w/ preemption disabled, and decremented or reset in the same context
* but w/ pool->lock held. The readers grab pool->lock and are
* guaranteed to see if the counter reached zero.
*/
int nr_running;
struct list_head worklist; /* L: list of pending works */ struct list_head worklist; /* L: list of pending works */
@ -777,7 +782,7 @@ static bool work_is_canceling(struct work_struct *work)
static bool __need_more_worker(struct worker_pool *pool) static bool __need_more_worker(struct worker_pool *pool)
{ {
return !atomic_read(&pool->nr_running); return !pool->nr_running;
} }
/* /*
@ -802,8 +807,7 @@ static bool may_start_working(struct worker_pool *pool)
/* Do I need to keep working? Called from currently running workers. */ /* Do I need to keep working? Called from currently running workers. */
static bool keep_working(struct worker_pool *pool) static bool keep_working(struct worker_pool *pool)
{ {
return !list_empty(&pool->worklist) && return !list_empty(&pool->worklist) && (pool->nr_running <= 1);
atomic_read(&pool->nr_running) <= 1;
} }
/* Do we need a new worker? Called from manager. */ /* Do we need a new worker? Called from manager. */
@ -873,7 +877,7 @@ void wq_worker_running(struct task_struct *task)
*/ */
preempt_disable(); preempt_disable();
if (!(worker->flags & WORKER_NOT_RUNNING)) if (!(worker->flags & WORKER_NOT_RUNNING))
atomic_inc(&worker->pool->nr_running); worker->pool->nr_running++;
preempt_enable(); preempt_enable();
worker->sleeping = 0; worker->sleeping = 0;
} }
@ -917,8 +921,8 @@ void wq_worker_sleeping(struct task_struct *task)
return; return;
} }
if (atomic_dec_and_test(&pool->nr_running) && pool->nr_running--;
!list_empty(&pool->worklist)) if (need_more_worker(pool))
wake_up_worker(pool); wake_up_worker(pool);
raw_spin_unlock_irq(&pool->lock); raw_spin_unlock_irq(&pool->lock);
} }
@ -973,7 +977,7 @@ static inline void worker_set_flags(struct worker *worker, unsigned int flags)
/* If transitioning into NOT_RUNNING, adjust nr_running. */ /* If transitioning into NOT_RUNNING, adjust nr_running. */
if ((flags & WORKER_NOT_RUNNING) && if ((flags & WORKER_NOT_RUNNING) &&
!(worker->flags & WORKER_NOT_RUNNING)) { !(worker->flags & WORKER_NOT_RUNNING)) {
atomic_dec(&pool->nr_running); pool->nr_running--;
} }
worker->flags |= flags; worker->flags |= flags;
@ -1005,7 +1009,7 @@ static inline void worker_clr_flags(struct worker *worker, unsigned int flags)
*/ */
if ((flags & WORKER_NOT_RUNNING) && (oflags & WORKER_NOT_RUNNING)) if ((flags & WORKER_NOT_RUNNING) && (oflags & WORKER_NOT_RUNNING))
if (!(worker->flags & WORKER_NOT_RUNNING)) if (!(worker->flags & WORKER_NOT_RUNNING))
atomic_inc(&pool->nr_running); pool->nr_running++;
} }
/** /**
@ -1806,8 +1810,7 @@ static void worker_enter_idle(struct worker *worker)
mod_timer(&pool->idle_timer, jiffies + IDLE_WORKER_TIMEOUT); mod_timer(&pool->idle_timer, jiffies + IDLE_WORKER_TIMEOUT);
/* Sanity check nr_running. */ /* Sanity check nr_running. */
WARN_ON_ONCE(pool->nr_workers == pool->nr_idle && WARN_ON_ONCE(pool->nr_workers == pool->nr_idle && pool->nr_running);
atomic_read(&pool->nr_running));
} }
/** /**
@ -4985,7 +4988,7 @@ static void unbind_workers(int cpu)
* an unbound (in terms of concurrency management) pool which * an unbound (in terms of concurrency management) pool which
* are served by workers tied to the pool. * are served by workers tied to the pool.
*/ */
atomic_set(&pool->nr_running, 0); pool->nr_running = 0;
/* /*
* With concurrency management just turned off, a busy * With concurrency management just turned off, a busy