* [PATCH 0/1] sched/wait: Introduce prepare_to_wait_event() @ 2013-10-07 16:17 Oleg Nesterov 2013-10-07 16:18 ` [PATCH 1/1] " Oleg Nesterov 0 siblings, 1 reply; 3+ messages in thread From: Oleg Nesterov @ 2013-10-07 16:17 UTC (permalink / raw) To: Ingo Molnar, Peter Zijlstra Cc: Paul McKenney, Linus Torvalds, Thomas Gleixner, Andrew Morton, linux-kernel On top of recent changes in wait.h from Peter. This is the same patch we already discussed, just "intr" was renamed to "__int". As for __maybe_unused, I think it is not needed. This "__int" is always used, even gcc won't generate the code due to "if (0)" check. Oleg. ^ permalink raw reply [flat|nested] 3+ messages in thread
* [PATCH 1/1] sched/wait: Introduce prepare_to_wait_event() 2013-10-07 16:17 [PATCH 0/1] sched/wait: Introduce prepare_to_wait_event() Oleg Nesterov @ 2013-10-07 16:18 ` Oleg Nesterov 2013-10-17 16:49 ` [tip:sched/core] " tip-bot for Oleg Nesterov 0 siblings, 1 reply; 3+ messages in thread From: Oleg Nesterov @ 2013-10-07 16:18 UTC (permalink / raw) To: Ingo Molnar, Peter Zijlstra Cc: Paul McKenney, Linus Torvalds, Thomas Gleixner, Andrew Morton, linux-kernel Add the new helper, prepare_to_wait_event() which should only be used by ___wait_event(). prepare_to_wait_event() returns -ERESTARTSYS if signal_pending_state() is true, otherwise it does prepare_to_wait/exclusive. This allows to uninline the signal-pending checks in wait_event*() macros. Also, it can initialize wait->private/func. We do not care if they were already initialized, the values are the same. This also shaves a couple of insns from the inlined code. This obviously makes prepare_*() path a little bit slower, but we are likely going to sleep anyway, so I think it makes sense to shrink .text, - 5126092 2959248 10117120 18202460 115bf5c vmlinux + 5124618 2955152 10117120 18196890 115a99a vmlinux on my build. Signed-off-by: Oleg Nesterov <oleg@redhat.com> --- include/linux/wait.h | 24 ++++++++++++++---------- kernel/wait.c | 24 ++++++++++++++++++++++++ 2 files changed, 38 insertions(+), 10 deletions(-) diff --git a/include/linux/wait.h b/include/linux/wait.h index a2726c7..ff9e20f 100644 --- a/include/linux/wait.h +++ b/include/linux/wait.h @@ -187,27 +187,30 @@ wait_queue_head_t *bit_waitqueue(void *, int); __cond || !__ret; \ }) -#define ___wait_signal_pending(state) \ - ((state == TASK_INTERRUPTIBLE && signal_pending(current)) || \ - (state == TASK_KILLABLE && fatal_signal_pending(current))) +#define ___wait_is_interruptible(state) \ + (!__builtin_constant_p(state) || \ + state == TASK_INTERRUPTIBLE || state == TASK_KILLABLE) \ #define ___wait_event(wq, condition, state, exclusive, ret, cmd) \ ({ \ __label__ __out; \ - DEFINE_WAIT(__wait); \ + wait_queue_t __wait; \ long __ret = ret; \ \ + INIT_LIST_HEAD(&__wait.task_list); \ + if (exclusive) \ + __wait.flags = WQ_FLAG_EXCLUSIVE; \ + else \ + __wait.flags = 0; \ + \ for (;;) { \ - if (exclusive) \ - prepare_to_wait_exclusive(&wq, &__wait, state); \ - else \ - prepare_to_wait(&wq, &__wait, state); \ + long __int = prepare_to_wait_event(&wq, &__wait, state);\ \ if (condition) \ break; \ \ - if (___wait_signal_pending(state)) { \ - __ret = -ERESTARTSYS; \ + if (___wait_is_interruptible(state) && __int) { \ + __ret = __int; \ if (exclusive) { \ abort_exclusive_wait(&wq, &__wait, \ state, NULL); \ @@ -791,6 +794,7 @@ extern long interruptible_sleep_on_timeout(wait_queue_head_t *q, signed long tim */ void prepare_to_wait(wait_queue_head_t *q, wait_queue_t *wait, int state); void prepare_to_wait_exclusive(wait_queue_head_t *q, wait_queue_t *wait, int state); +long prepare_to_wait_event(wait_queue_head_t *q, wait_queue_t *wait, int state); void finish_wait(wait_queue_head_t *q, wait_queue_t *wait); void abort_exclusive_wait(wait_queue_head_t *q, wait_queue_t *wait, unsigned int mode, void *key); int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key); diff --git a/kernel/wait.c b/kernel/wait.c index d550920..de21c63 100644 --- a/kernel/wait.c +++ b/kernel/wait.c @@ -92,6 +92,30 @@ prepare_to_wait_exclusive(wait_queue_head_t *q, wait_queue_t *wait, int state) } EXPORT_SYMBOL(prepare_to_wait_exclusive); +long prepare_to_wait_event(wait_queue_head_t *q, wait_queue_t *wait, int state) +{ + unsigned long flags; + + if (signal_pending_state(state, current)) + return -ERESTARTSYS; + + wait->private = current; + wait->func = autoremove_wake_function; + + spin_lock_irqsave(&q->lock, flags); + if (list_empty(&wait->task_list)) { + if (wait->flags & WQ_FLAG_EXCLUSIVE) + __add_wait_queue_tail(q, wait); + else + __add_wait_queue(q, wait); + } + set_current_state(state); + spin_unlock_irqrestore(&q->lock, flags); + + return 0; +} +EXPORT_SYMBOL(prepare_to_wait_event); + /** * finish_wait - clean up after waiting in a queue * @q: waitqueue waited on -- 1.5.5.1 ^ permalink raw reply [flat|nested] 3+ messages in thread
* [tip:sched/core] sched/wait: Introduce prepare_to_wait_event() 2013-10-07 16:18 ` [PATCH 1/1] " Oleg Nesterov @ 2013-10-17 16:49 ` tip-bot for Oleg Nesterov 0 siblings, 0 replies; 3+ messages in thread From: tip-bot for Oleg Nesterov @ 2013-10-17 16:49 UTC (permalink / raw) To: linux-tip-commits; +Cc: linux-kernel, hpa, mingo, peterz, oleg, tglx Commit-ID: c2d816443ef305aba8eaf0bf368f4d3d87494f06 Gitweb: http://git.kernel.org/tip/c2d816443ef305aba8eaf0bf368f4d3d87494f06 Author: Oleg Nesterov <oleg@redhat.com> AuthorDate: Mon, 7 Oct 2013 18:18:24 +0200 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Wed, 16 Oct 2013 14:22:18 +0200 sched/wait: Introduce prepare_to_wait_event() Add the new helper, prepare_to_wait_event() which should only be used by ___wait_event(). prepare_to_wait_event() returns -ERESTARTSYS if signal_pending_state() is true, otherwise it does prepare_to_wait/exclusive. This allows to uninline the signal-pending checks in wait_event*() macros. Also, it can initialize wait->private/func. We do not care if they were already initialized, the values are the same. This also shaves a couple of insns from the inlined code. This obviously makes prepare_*() path a little bit slower, but we are likely going to sleep anyway, so I think it makes sense to shrink .text: text data bss dec hex filename =================================================== before: 5126092 2959248 10117120 18202460 115bf5c vmlinux after: 5124618 2955152 10117120 18196890 115a99a vmlinux on my build. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20131007161824.GA29757@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> --- include/linux/wait.h | 24 ++++++++++++++---------- kernel/wait.c | 24 ++++++++++++++++++++++++ 2 files changed, 38 insertions(+), 10 deletions(-) diff --git a/include/linux/wait.h b/include/linux/wait.h index 04c0260..ec099b0 100644 --- a/include/linux/wait.h +++ b/include/linux/wait.h @@ -187,27 +187,30 @@ wait_queue_head_t *bit_waitqueue(void *, int); __cond || !__ret; \ }) -#define ___wait_signal_pending(state) \ - ((state == TASK_INTERRUPTIBLE && signal_pending(current)) || \ - (state == TASK_KILLABLE && fatal_signal_pending(current))) +#define ___wait_is_interruptible(state) \ + (!__builtin_constant_p(state) || \ + state == TASK_INTERRUPTIBLE || state == TASK_KILLABLE) \ #define ___wait_event(wq, condition, state, exclusive, ret, cmd) \ ({ \ __label__ __out; \ - DEFINE_WAIT(__wait); \ + wait_queue_t __wait; \ long __ret = ret; \ \ + INIT_LIST_HEAD(&__wait.task_list); \ + if (exclusive) \ + __wait.flags = WQ_FLAG_EXCLUSIVE; \ + else \ + __wait.flags = 0; \ + \ for (;;) { \ - if (exclusive) \ - prepare_to_wait_exclusive(&wq, &__wait, state); \ - else \ - prepare_to_wait(&wq, &__wait, state); \ + long __int = prepare_to_wait_event(&wq, &__wait, state);\ \ if (condition) \ break; \ \ - if (___wait_signal_pending(state)) { \ - __ret = -ERESTARTSYS; \ + if (___wait_is_interruptible(state) && __int) { \ + __ret = __int; \ if (exclusive) { \ abort_exclusive_wait(&wq, &__wait, \ state, NULL); \ @@ -791,6 +794,7 @@ extern long interruptible_sleep_on_timeout(wait_queue_head_t *q, signed long tim */ void prepare_to_wait(wait_queue_head_t *q, wait_queue_t *wait, int state); void prepare_to_wait_exclusive(wait_queue_head_t *q, wait_queue_t *wait, int state); +long prepare_to_wait_event(wait_queue_head_t *q, wait_queue_t *wait, int state); void finish_wait(wait_queue_head_t *q, wait_queue_t *wait); void abort_exclusive_wait(wait_queue_head_t *q, wait_queue_t *wait, unsigned int mode, void *key); int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key); diff --git a/kernel/wait.c b/kernel/wait.c index d550920..de21c63 100644 --- a/kernel/wait.c +++ b/kernel/wait.c @@ -92,6 +92,30 @@ prepare_to_wait_exclusive(wait_queue_head_t *q, wait_queue_t *wait, int state) } EXPORT_SYMBOL(prepare_to_wait_exclusive); +long prepare_to_wait_event(wait_queue_head_t *q, wait_queue_t *wait, int state) +{ + unsigned long flags; + + if (signal_pending_state(state, current)) + return -ERESTARTSYS; + + wait->private = current; + wait->func = autoremove_wake_function; + + spin_lock_irqsave(&q->lock, flags); + if (list_empty(&wait->task_list)) { + if (wait->flags & WQ_FLAG_EXCLUSIVE) + __add_wait_queue_tail(q, wait); + else + __add_wait_queue(q, wait); + } + set_current_state(state); + spin_unlock_irqrestore(&q->lock, flags); + + return 0; +} +EXPORT_SYMBOL(prepare_to_wait_event); + /** * finish_wait - clean up after waiting in a queue * @q: waitqueue waited on ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2013-10-17 16:50 UTC | newest] Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2013-10-07 16:17 [PATCH 0/1] sched/wait: Introduce prepare_to_wait_event() Oleg Nesterov 2013-10-07 16:18 ` [PATCH 1/1] " Oleg Nesterov 2013-10-17 16:49 ` [tip:sched/core] " tip-bot for Oleg Nesterov
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