From cbbce82209490df8b68da9aec0d642451fe0a668 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Thu, 25 Sep 2014 13:55:19 +1000 Subject: SCHED: add some "wait..on_bit...timeout()" interfaces. In commit c1221321b7c25b53204447cff9949a6d5a7ddddc sched: Allow wait_on_bit_action() functions to support a timeout I suggested that a "wait_on_bit_timeout()" interface would not meet my need. This isn't true - I was just over-engineering. Including a 'private' field in wait_bit_key instead of a focused "timeout" field was just premature generalization. If some other use is ever found, it can be generalized or added later. So this patch renames "private" to "timeout" with a meaning "stop waiting when "jiffies" reaches or passes "timeout", and adds two of the many possible wait..bit..timeout() interfaces: wait_on_page_bit_killable_timeout(), which is the one I want to use, and out_of_line_wait_on_bit_timeout() which is a reasonably general example. Others can be added as needed. Acked-by: Peter Zijlstra (Intel) Signed-off-by: NeilBrown Acked-by: Ingo Molnar Signed-off-by: Trond Myklebust --- kernel/sched/wait.c | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) (limited to 'kernel/sched') diff --git a/kernel/sched/wait.c b/kernel/sched/wait.c index 15cab1a4f84e..5a62915f47a8 100644 --- a/kernel/sched/wait.c +++ b/kernel/sched/wait.c @@ -343,6 +343,18 @@ int __sched out_of_line_wait_on_bit(void *word, int bit, } EXPORT_SYMBOL(out_of_line_wait_on_bit); +int __sched out_of_line_wait_on_bit_timeout( + void *word, int bit, wait_bit_action_f *action, + unsigned mode, unsigned long timeout) +{ + wait_queue_head_t *wq = bit_waitqueue(word, bit); + DEFINE_WAIT_BIT(wait, word, bit); + + wait.key.timeout = jiffies + timeout; + return __wait_on_bit(wq, &wait, action, mode); +} +EXPORT_SYMBOL_GPL(out_of_line_wait_on_bit_timeout); + int __sched __wait_on_bit_lock(wait_queue_head_t *wq, struct wait_bit_queue *q, wait_bit_action_f *action, unsigned mode) @@ -520,3 +532,27 @@ __sched int bit_wait_io(struct wait_bit_key *word) return 0; } EXPORT_SYMBOL(bit_wait_io); + +__sched int bit_wait_timeout(struct wait_bit_key *word) +{ + unsigned long now = ACCESS_ONCE(jiffies); + if (signal_pending_state(current->state, current)) + return 1; + if (time_after_eq(now, word->timeout)) + return -EAGAIN; + schedule_timeout(word->timeout - now); + return 0; +} +EXPORT_SYMBOL_GPL(bit_wait_timeout); + +__sched int bit_wait_io_timeout(struct wait_bit_key *word) +{ + unsigned long now = ACCESS_ONCE(jiffies); + if (signal_pending_state(current->state, current)) + return 1; + if (time_after_eq(now, word->timeout)) + return -EAGAIN; + io_schedule_timeout(word->timeout - now); + return 0; +} +EXPORT_SYMBOL_GPL(bit_wait_io_timeout); -- cgit v1.2.3