Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754045AbaGYOst (ORCPT ); Fri, 25 Jul 2014 10:48:49 -0400 Received: from smtp.codeaurora.org ([198.145.11.231]:52151 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752325AbaGYOss (ORCPT ); Fri, 25 Jul 2014 10:48:48 -0400 From: Chintan Pandya To: tglx@linutronix.de, john.stultz@linaro.org, peterz@infradead.org, mingo@redhat.com, hughd@google.com, akpm@linux-foundation.org Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Chintan Pandya Subject: [PATCH v2 1/2] timer: provide an api for deferrable timeout Date: Fri, 25 Jul 2014 20:18:17 +0530 Message-Id: <1406299698-6357-1-git-send-email-cpandya@codeaurora.org> X-Mailer: git-send-email 1.8.2.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org schedule_timeout wakes up the CPU from IDLE state. For some use cases it is not desirable, hence introduce a convenient API (schedule_timeout_deferrable_interruptible) on similar pattern which uses a deferrable timer. Signed-off-by: Chintan Pandya --- This patch has been newly introduced in patch v2 include/linux/sched.h | 2 ++ kernel/time/timer.c | 27 ++++++++++++++++++++++++--- 2 files changed, 26 insertions(+), 3 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index 89f531e..10b154e 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -377,6 +377,8 @@ extern int in_sched_functions(unsigned long addr); #define MAX_SCHEDULE_TIMEOUT LONG_MAX extern signed long schedule_timeout(signed long timeout); extern signed long schedule_timeout_interruptible(signed long timeout); +extern signed long +schedule_timeout_deferrable_interruptible(signed long timeout); extern signed long schedule_timeout_killable(signed long timeout); extern signed long schedule_timeout_uninterruptible(signed long timeout); asmlinkage void schedule(void); diff --git a/kernel/time/timer.c b/kernel/time/timer.c index aca5dfe..e81a301 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -1432,7 +1432,7 @@ static void process_timeout(unsigned long __data) } /** - * schedule_timeout - sleep until timeout + * __schedule_timeout - sleep until timeout * @timeout: timeout value in jiffies * * Make the current task sleep until @timeout jiffies have @@ -1457,7 +1457,8 @@ static void process_timeout(unsigned long __data) * * In all cases the return value is guaranteed to be non-negative. */ -signed long __sched schedule_timeout(signed long timeout) +static signed long +__sched __schedule_timeout(signed long timeout, unsigned long flag) { struct timer_list timer; unsigned long expire; @@ -1493,7 +1494,13 @@ signed long __sched schedule_timeout(signed long timeout) expire = timeout + jiffies; - setup_timer_on_stack(&timer, process_timeout, (unsigned long)current); + if (flag & TIMER_DEFERRABLE) + setup_deferrable_timer_on_stack(&timer, process_timeout, + (unsigned long)current); + else + setup_timer_on_stack(&timer, process_timeout, + (unsigned long)current); + __mod_timer(&timer, expire, false, TIMER_NOT_PINNED); schedule(); del_singleshot_timer_sync(&timer); @@ -1506,12 +1513,26 @@ signed long __sched schedule_timeout(signed long timeout) out: return timeout < 0 ? 0 : timeout; } + +signed long __sched schedule_timeout(signed long timeout) +{ + return __schedule_timeout(timeout, 0); +} EXPORT_SYMBOL(schedule_timeout); /* * We can use __set_current_state() here because schedule_timeout() calls * schedule() unconditionally. */ + +signed long +__sched schedule_timeout_deferrable_interruptible(signed long timeout) +{ + __set_current_state(TASK_INTERRUPTIBLE); + return __schedule_timeout(timeout, TIMER_DEFERRABLE); +} +EXPORT_SYMBOL(schedule_timeout_deferrable_interruptible); + signed long __sched schedule_timeout_interruptible(signed long timeout) { __set_current_state(TASK_INTERRUPTIBLE); -- Chintan Pandya QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, hosted by The Linux Foundation -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/