From 50816c48997af857d4bab3dca1aba90339705e96 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Sun, 5 Mar 2017 10:33:16 +0100 Subject: sched/wait: Standardize internal naming of wait-queue entries So the various wait-queue entry variables in include/linux/wait.h and kernel/sched/wait.c are named in a colorfully inconsistent way: wait_queue_entry_t *wait wait_queue_entry_t *__wait (even in plain C code!) wait_queue_entry_t *q (!) wait_queue_entry_t *new (making anyone who knows C++ cringe) wait_queue_entry_t *old I think part of the reason for the inconsistency is the constant apparent confusion about what a wait queue 'head' versus 'entry' is. ( Some of the documentation talks about a 'wait descriptor', which is the wait-queue entry itself - further adding to the confusion. ) The most common name is 'wait', but that in itself is somewhat ambiguous as well, as it does not really make it clear whether it's a wait-queue entry or head. To improve all this name the wait-queue entry structure parameters and variables consistently and push through this naming into all the wait.h and wait.c code: struct wait_queue_entry *wq_entry The 'wq_' prefix makes it easy to grep for, and we also use the opportunity to move away from the typedef to a plain 'struct' naming: in the kernel we typically reserve typedefs for cases where a C structure is really small and somewhat opaque - such as pte_t. wait-queue entries are neither small nor opaque, so use the more standard 'struct xxx_entry' list management code nomenclature instead. ( We don't touch external users, and we preserve the typedef as well for actual wait-queue users, to reduce unnecessary churn. ) Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar --- kernel/sched/wait.c | 98 ++++++++++++++++++++++++++--------------------------- 1 file changed, 49 insertions(+), 49 deletions(-) (limited to 'kernel/sched') diff --git a/kernel/sched/wait.c b/kernel/sched/wait.c index 301ea02dede0..c37b3140763e 100644 --- a/kernel/sched/wait.c +++ b/kernel/sched/wait.c @@ -21,34 +21,34 @@ void __init_waitqueue_head(wait_queue_head_t *q, const char *name, struct lock_c EXPORT_SYMBOL(__init_waitqueue_head); -void add_wait_queue(wait_queue_head_t *q, wait_queue_entry_t *wait) +void add_wait_queue(wait_queue_head_t *q, struct wait_queue_entry *wq_entry) { unsigned long flags; - wait->flags &= ~WQ_FLAG_EXCLUSIVE; + wq_entry->flags &= ~WQ_FLAG_EXCLUSIVE; spin_lock_irqsave(&q->lock, flags); - __add_wait_queue(q, wait); + __add_wait_queue_entry_tail(q, wq_entry); spin_unlock_irqrestore(&q->lock, flags); } EXPORT_SYMBOL(add_wait_queue); -void add_wait_queue_exclusive(wait_queue_head_t *q, wait_queue_entry_t *wait) +void add_wait_queue_exclusive(wait_queue_head_t *q, struct wait_queue_entry *wq_entry) { unsigned long flags; - wait->flags |= WQ_FLAG_EXCLUSIVE; + wq_entry->flags |= WQ_FLAG_EXCLUSIVE; spin_lock_irqsave(&q->lock, flags); - __add_wait_queue_entry_tail(q, wait); + __add_wait_queue_entry_tail(q, wq_entry); spin_unlock_irqrestore(&q->lock, flags); } EXPORT_SYMBOL(add_wait_queue_exclusive); -void remove_wait_queue(wait_queue_head_t *q, wait_queue_entry_t *wait) +void remove_wait_queue(wait_queue_head_t *q, struct wait_queue_entry *wq_entry) { unsigned long flags; spin_lock_irqsave(&q->lock, flags); - __remove_wait_queue(q, wait); + __remove_wait_queue(q, wq_entry); spin_unlock_irqrestore(&q->lock, flags); } EXPORT_SYMBOL(remove_wait_queue); @@ -170,43 +170,43 @@ EXPORT_SYMBOL_GPL(__wake_up_sync); /* For internal use only */ * loads to move into the critical region). */ void -prepare_to_wait(wait_queue_head_t *q, wait_queue_entry_t *wait, int state) +prepare_to_wait(wait_queue_head_t *q, struct wait_queue_entry *wq_entry, int state) { unsigned long flags; - wait->flags &= ~WQ_FLAG_EXCLUSIVE; + wq_entry->flags &= ~WQ_FLAG_EXCLUSIVE; spin_lock_irqsave(&q->lock, flags); - if (list_empty(&wait->task_list)) - __add_wait_queue(q, wait); + if (list_empty(&wq_entry->task_list)) + __add_wait_queue(q, wq_entry); set_current_state(state); spin_unlock_irqrestore(&q->lock, flags); } EXPORT_SYMBOL(prepare_to_wait); void -prepare_to_wait_exclusive(wait_queue_head_t *q, wait_queue_entry_t *wait, int state) +prepare_to_wait_exclusive(wait_queue_head_t *q, struct wait_queue_entry *wq_entry, int state) { unsigned long flags; - wait->flags |= WQ_FLAG_EXCLUSIVE; + wq_entry->flags |= WQ_FLAG_EXCLUSIVE; spin_lock_irqsave(&q->lock, flags); - if (list_empty(&wait->task_list)) - __add_wait_queue_entry_tail(q, wait); + if (list_empty(&wq_entry->task_list)) + __add_wait_queue_entry_tail(q, wq_entry); set_current_state(state); spin_unlock_irqrestore(&q->lock, flags); } EXPORT_SYMBOL(prepare_to_wait_exclusive); -void init_wait_entry(wait_queue_entry_t *wait, int flags) +void init_wait_entry(struct wait_queue_entry *wq_entry, int flags) { - wait->flags = flags; - wait->private = current; - wait->func = autoremove_wake_function; - INIT_LIST_HEAD(&wait->task_list); + wq_entry->flags = flags; + wq_entry->private = current; + wq_entry->func = autoremove_wake_function; + INIT_LIST_HEAD(&wq_entry->task_list); } EXPORT_SYMBOL(init_wait_entry); -long prepare_to_wait_event(wait_queue_head_t *q, wait_queue_entry_t *wait, int state) +long prepare_to_wait_event(wait_queue_head_t *q, struct wait_queue_entry *wq_entry, int state) { unsigned long flags; long ret = 0; @@ -225,14 +225,14 @@ long prepare_to_wait_event(wait_queue_head_t *q, wait_queue_entry_t *wait, int s * can't see us, it should wake up another exclusive waiter if * we fail. */ - list_del_init(&wait->task_list); + list_del_init(&wq_entry->task_list); ret = -ERESTARTSYS; } else { - if (list_empty(&wait->task_list)) { - if (wait->flags & WQ_FLAG_EXCLUSIVE) - __add_wait_queue_entry_tail(q, wait); + if (list_empty(&wq_entry->task_list)) { + if (wq_entry->flags & WQ_FLAG_EXCLUSIVE) + __add_wait_queue_entry_tail(q, wq_entry); else - __add_wait_queue(q, wait); + __add_wait_queue(q, wq_entry); } set_current_state(state); } @@ -284,13 +284,13 @@ EXPORT_SYMBOL(do_wait_intr_irq); /** * finish_wait - clean up after waiting in a queue * @q: waitqueue waited on - * @wait: wait descriptor + * @wq_entry: wait descriptor * * Sets current thread back to running state and removes * the wait descriptor from the given waitqueue if still * queued. */ -void finish_wait(wait_queue_head_t *q, wait_queue_entry_t *wait) +void finish_wait(wait_queue_head_t *q, struct wait_queue_entry *wq_entry) { unsigned long flags; @@ -308,20 +308,20 @@ void finish_wait(wait_queue_head_t *q, wait_queue_entry_t *wait) * have _one_ other CPU that looks at or modifies * the list). */ - if (!list_empty_careful(&wait->task_list)) { + if (!list_empty_careful(&wq_entry->task_list)) { spin_lock_irqsave(&q->lock, flags); - list_del_init(&wait->task_list); + list_del_init(&wq_entry->task_list); spin_unlock_irqrestore(&q->lock, flags); } } EXPORT_SYMBOL(finish_wait); -int autoremove_wake_function(wait_queue_entry_t *wait, unsigned mode, int sync, void *key) +int autoremove_wake_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync, void *key) { - int ret = default_wake_function(wait, mode, sync, key); + int ret = default_wake_function(wq_entry, mode, sync, key); if (ret) - list_del_init(&wait->task_list); + list_del_init(&wq_entry->task_list); return ret; } EXPORT_SYMBOL(autoremove_wake_function); @@ -341,17 +341,17 @@ static inline bool is_kthread_should_stop(void) * * p->state = mode; condition = true; * smp_mb(); // A smp_wmb(); // C - * if (!wait->flags & WQ_FLAG_WOKEN) wait->flags |= WQ_FLAG_WOKEN; + * if (!wq_entry->flags & WQ_FLAG_WOKEN) wq_entry->flags |= WQ_FLAG_WOKEN; * schedule() try_to_wake_up(); * p->state = TASK_RUNNING; ~~~~~~~~~~~~~~~~~~ - * wait->flags &= ~WQ_FLAG_WOKEN; condition = true; + * wq_entry->flags &= ~WQ_FLAG_WOKEN; condition = true; * smp_mb() // B smp_wmb(); // C - * wait->flags |= WQ_FLAG_WOKEN; + * wq_entry->flags |= WQ_FLAG_WOKEN; * } * remove_wait_queue(&wq, &wait); * */ -long wait_woken(wait_queue_entry_t *wait, unsigned mode, long timeout) +long wait_woken(struct wait_queue_entry *wq_entry, unsigned mode, long timeout) { set_current_state(mode); /* A */ /* @@ -359,7 +359,7 @@ long wait_woken(wait_queue_entry_t *wait, unsigned mode, long timeout) * woken_wake_function() such that if we observe WQ_FLAG_WOKEN we must * also observe all state before the wakeup. */ - if (!(wait->flags & WQ_FLAG_WOKEN) && !is_kthread_should_stop()) + if (!(wq_entry->flags & WQ_FLAG_WOKEN) && !is_kthread_should_stop()) timeout = schedule_timeout(timeout); __set_current_state(TASK_RUNNING); @@ -369,13 +369,13 @@ long wait_woken(wait_queue_entry_t *wait, unsigned mode, long timeout) * condition being true _OR_ WQ_FLAG_WOKEN such that we will not miss * an event. */ - smp_store_mb(wait->flags, wait->flags & ~WQ_FLAG_WOKEN); /* B */ + smp_store_mb(wq_entry->flags, wq_entry->flags & ~WQ_FLAG_WOKEN); /* B */ return timeout; } EXPORT_SYMBOL(wait_woken); -int woken_wake_function(wait_queue_entry_t *wait, unsigned mode, int sync, void *key) +int woken_wake_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync, void *key) { /* * Although this function is called under waitqueue lock, LOCK @@ -385,24 +385,24 @@ int woken_wake_function(wait_queue_entry_t *wait, unsigned mode, int sync, void * and is paired with smp_store_mb() in wait_woken(). */ smp_wmb(); /* C */ - wait->flags |= WQ_FLAG_WOKEN; + wq_entry->flags |= WQ_FLAG_WOKEN; - return default_wake_function(wait, mode, sync, key); + return default_wake_function(wq_entry, mode, sync, key); } EXPORT_SYMBOL(woken_wake_function); -int wake_bit_function(wait_queue_entry_t *wait, unsigned mode, int sync, void *arg) +int wake_bit_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync, void *arg) { struct wait_bit_key *key = arg; struct wait_bit_queue *wait_bit - = container_of(wait, struct wait_bit_queue, wait); + = container_of(wq_entry, struct wait_bit_queue, wait); if (wait_bit->key.flags != key->flags || wait_bit->key.bit_nr != key->bit_nr || test_bit(key->bit_nr, key->flags)) return 0; else - return autoremove_wake_function(wait, mode, sync, key); + return autoremove_wake_function(wq_entry, mode, sync, key); } EXPORT_SYMBOL(wake_bit_function); @@ -534,19 +534,19 @@ static inline wait_queue_head_t *atomic_t_waitqueue(atomic_t *p) return bit_waitqueue(p, 0); } -static int wake_atomic_t_function(wait_queue_entry_t *wait, unsigned mode, int sync, +static int wake_atomic_t_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync, void *arg) { struct wait_bit_key *key = arg; struct wait_bit_queue *wait_bit - = container_of(wait, struct wait_bit_queue, wait); + = container_of(wq_entry, struct wait_bit_queue, wait); atomic_t *val = key->flags; if (wait_bit->key.flags != key->flags || wait_bit->key.bit_nr != key->bit_nr || atomic_read(val) != 0) return 0; - return autoremove_wake_function(wait, mode, sync, key); + return autoremove_wake_function(wq_entry, mode, sync, key); } /* -- cgit v1.2.1