From: Lai Jiangshan Date: Mon, 25 Mar 2013 23:57:17 +0000 (-0700) Subject: workqueue: rename wq->flush_mutex to wq->mutex X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=3c25a55daadc7e7058926f5728fba7721d824ffb;p=openwrt%2Fstaging%2Fblogic.git 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 Signed-off-by: Tejun Heo --- diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 064157eac4c8..d448edae3513 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -118,8 +118,6 @@ enum { * 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 @@ enum { * * 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 @@ struct pool_workqueue { 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 @@ struct pool_workqueue { * 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 wq_device; 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 @@ static void insert_wq_barrier(struct pool_workqueue *pwq, * 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 @@ void flush_workqueue(struct workqueue_struct *wq) 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 @@ void flush_workqueue(struct workqueue_struct *wq) 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 @@ void flush_workqueue(struct workqueue_struct *wq) 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 @@ void flush_workqueue(struct workqueue_struct *wq) } out_unlock: - mutex_unlock(&wq->flush_mutex); + mutex_unlock(&wq->mutex); } EXPORT_SYMBOL_GPL(flush_workqueue); @@ -3550,15 +3550,15 @@ static void pwq_unbound_release_workfn(struct work_struct *work) 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 @@ static void init_and_link_pwq(struct pool_workqueue *pwq, 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 @@ static void init_and_link_pwq(struct pool_workqueue *pwq, 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 @@ struct workqueue_struct *__alloc_workqueue_key(const char *fmt, /* 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);