workqueue: rename wq->flush_mutex to wq->mutex
Currently pwq->flush_mutex protects many fields of a workqueue
including, especially, the pwqs list. We're going to expand this
mutex to protect most of a workqueue and eventually replace pwq_lock,
which will make locking simpler and easier to understand.
Drop the "flush_" prefix in preparation.
This patch is pure rename.
tj: Rebased on top of the current dev branch. Updated description.
Use WQ: and WR: instead of Q: and QR: for synchronization labels.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 064157e..d448eda 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -118,8 +118,6 @@
* cpu or grabbing pool->lock is enough for read access. If
* POOL_DISASSOCIATED is set, it's identical to L.
*
- * F: wq->flush_mutex protected.
- *
* MG: pool->manager_mutex and pool->lock protected. Writes require both
* locks. Reads can happen under either lock.
*
@@ -129,8 +127,10 @@
*
* PW: pwq_lock protected.
*
- * FR: wq->flush_mutex and pwq_lock protected for writes. Sched-RCU
- * protected for reads.
+ * WQ: wq->mutex protected.
+ *
+ * WR: wq->mutex and pwq_lock protected for writes. Sched-RCU protected
+ * for reads.
*
* MD: wq_mayday_lock protected.
*/
@@ -197,7 +197,7 @@
int nr_active; /* L: nr of active works */
int max_active; /* L: max active works */
struct list_head delayed_works; /* L: delayed works */
- struct list_head pwqs_node; /* FR: node on wq->pwqs */
+ struct list_head pwqs_node; /* WR: node on wq->pwqs */
struct list_head mayday_node; /* MD: node on wq->maydays */
/*
@@ -214,8 +214,8 @@
* Structure used to wait for workqueue flush.
*/
struct wq_flusher {
- struct list_head list; /* F: list of flushers */
- int flush_color; /* F: flush color waiting for */
+ struct list_head list; /* WQ: list of flushers */
+ int flush_color; /* WQ: flush color waiting for */
struct completion done; /* flush completion */
};
@@ -228,16 +228,16 @@
struct workqueue_struct {
unsigned int flags; /* PL: WQ_* flags */
struct pool_workqueue __percpu *cpu_pwqs; /* I: per-cpu pwq's */
- struct list_head pwqs; /* FR: all pwqs of this wq */
+ struct list_head pwqs; /* WR: all pwqs of this wq */
struct list_head list; /* PL: list of all workqueues */
- struct mutex flush_mutex; /* protects wq flushing */
- int work_color; /* F: current work color */
- int flush_color; /* F: current flush color */
+ struct mutex mutex; /* protects this wq */
+ int work_color; /* WQ: current work color */
+ int flush_color; /* WQ: current flush color */
atomic_t nr_pwqs_to_flush; /* flush in progress */
- struct wq_flusher *first_flusher; /* F: first flusher */
- struct list_head flusher_queue; /* F: flush waiters */
- struct list_head flusher_overflow; /* F: flush overflow list */
+ struct wq_flusher *first_flusher; /* WQ: first flusher */
+ struct list_head flusher_queue; /* WQ: flush waiters */
+ struct list_head flusher_overflow; /* WQ: flush overflow list */
struct list_head maydays; /* MD: pwqs requesting rescue */
struct worker *rescuer; /* I: rescue worker */
@@ -2460,7 +2460,7 @@
* advanced to @work_color.
*
* CONTEXT:
- * mutex_lock(wq->flush_mutex).
+ * mutex_lock(wq->mutex).
*
* RETURNS:
* %true if @flush_color >= 0 and there's something to flush. %false
@@ -2529,7 +2529,7 @@
lock_map_acquire(&wq->lockdep_map);
lock_map_release(&wq->lockdep_map);
- mutex_lock(&wq->flush_mutex);
+ mutex_lock(&wq->mutex);
/*
* Start-to-wait phase
@@ -2574,7 +2574,7 @@
list_add_tail(&this_flusher.list, &wq->flusher_overflow);
}
- mutex_unlock(&wq->flush_mutex);
+ mutex_unlock(&wq->mutex);
wait_for_completion(&this_flusher.done);
@@ -2587,7 +2587,7 @@
if (wq->first_flusher != &this_flusher)
return;
- mutex_lock(&wq->flush_mutex);
+ mutex_lock(&wq->mutex);
/* we might have raced, check again with mutex held */
if (wq->first_flusher != &this_flusher)
@@ -2659,7 +2659,7 @@
}
out_unlock:
- mutex_unlock(&wq->flush_mutex);
+ mutex_unlock(&wq->mutex);
}
EXPORT_SYMBOL_GPL(flush_workqueue);
@@ -3550,15 +3550,15 @@
return;
/*
- * Unlink @pwq. Synchronization against flush_mutex isn't strictly
+ * Unlink @pwq. Synchronization against wq->mutex isn't strictly
* necessary on release but do it anyway. It's easier to verify
* and consistent with the linking path.
*/
- mutex_lock(&wq->flush_mutex);
+ mutex_lock(&wq->mutex);
spin_lock_irq(&pwq_lock);
list_del_rcu(&pwq->pwqs_node);
spin_unlock_irq(&pwq_lock);
- mutex_unlock(&wq->flush_mutex);
+ mutex_unlock(&wq->mutex);
put_unbound_pool(pool);
call_rcu_sched(&pwq->rcu, rcu_free_pwq);
@@ -3627,12 +3627,12 @@
INIT_LIST_HEAD(&pwq->mayday_node);
INIT_WORK(&pwq->unbound_release_work, pwq_unbound_release_workfn);
- mutex_lock(&wq->flush_mutex);
+ mutex_lock(&wq->mutex);
spin_lock_irq(&pwq_lock);
/*
* Set the matching work_color. This is synchronized with
- * flush_mutex to avoid confusing flush_workqueue().
+ * wq->mutex to avoid confusing flush_workqueue().
*/
if (p_last_pwq)
*p_last_pwq = first_pwq(wq);
@@ -3645,7 +3645,7 @@
list_add_rcu(&pwq->pwqs_node, &wq->pwqs);
spin_unlock_irq(&pwq_lock);
- mutex_unlock(&wq->flush_mutex);
+ mutex_unlock(&wq->mutex);
}
/**
@@ -3762,7 +3762,7 @@
/* init wq */
wq->flags = flags;
wq->saved_max_active = max_active;
- mutex_init(&wq->flush_mutex);
+ mutex_init(&wq->mutex);
atomic_set(&wq->nr_pwqs_to_flush, 0);
INIT_LIST_HEAD(&wq->pwqs);
INIT_LIST_HEAD(&wq->flusher_queue);