Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756327Ab2BUXhB (ORCPT ); Tue, 21 Feb 2012 18:37:01 -0500 Received: from ogre.sisk.pl ([217.79.144.158]:35775 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751462Ab2BUXfX (ORCPT ); Tue, 21 Feb 2012 18:35:23 -0500 From: "Rafael J. Wysocki" To: Linux PM list Subject: [RFC][PATCH 2/7] PM / Sleep: Use wait queue to signal "no wakeup events in progress" Date: Wed, 22 Feb 2012 00:33:25 +0100 User-Agent: KMail/1.13.6 (Linux/3.3.0-rc4+; KDE/4.6.0; x86_64; ; ) Cc: LKML , Magnus Damm , markgross@thegnar.org, Matthew Garrett , Greg KH , Arve =?utf-8?q?Hj=C3=B8nnev=C3=A5g?= , John Stultz , Brian Swetland , Neil Brown , Alan Stern , Dmitry Torokhov References: <201202070200.55505.rjw@sisk.pl> <201202220031.46219.rjw@sisk.pl> In-Reply-To: <201202220031.46219.rjw@sisk.pl> MIME-Version: 1.0 Content-Type: Text/Plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <201202220033.25523.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2708 Lines: 84 From: Rafael J. Wysocki The current wakeup source deactivation code doesn't do anything when the counter of wakeup events in progress goes down to zero, which requires pm_get_wakeup_count() to poll that counter periodically. Although this reduces the average time it takes to deactivate a wakeup source, it also may lead to a substantial amount of unnecessary polling if there are extended periods of wakeup activity. Thus it seems reasonable to use a wait queue for signaling the "no wakeup events in progress" condition and remove the polling. Signed-off-by: Rafael J. Wysocki --- drivers/base/power/wakeup.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) Index: linux/drivers/base/power/wakeup.c =================================================================== --- linux.orig/drivers/base/power/wakeup.c +++ linux/drivers/base/power/wakeup.c @@ -17,8 +17,6 @@ #include "power.h" -#define TIMEOUT 100 - /* * If set, the suspend/hibernate code will abort transitions to a sleep state * if wakeup events are registered during or immediately before the transition. @@ -52,6 +50,8 @@ static void pm_wakeup_timer_fn(unsigned static LIST_HEAD(wakeup_sources); +static DECLARE_WAIT_QUEUE_HEAD(wakeup_count_wait_queue); + /** * wakeup_source_prepare - Prepare a new wakeup source for initialization. * @ws: Wakeup source to prepare. @@ -442,6 +442,7 @@ EXPORT_SYMBOL_GPL(pm_stay_awake); */ static void wakeup_source_deactivate(struct wakeup_source *ws) { + unsigned int cnt, inpr; ktime_t duration; ktime_t now; @@ -476,6 +477,10 @@ static void wakeup_source_deactivate(str * couter of wakeup events in progress simultaneously. */ atomic_add(MAX_IN_PROGRESS, &combined_event_count); + + split_counters(&cnt, &inpr); + if (!inpr && waitqueue_active(&wakeup_count_wait_queue)) + wake_up(&wakeup_count_wait_queue); } /** @@ -667,14 +672,19 @@ bool pm_wakeup_pending(void) bool pm_get_wakeup_count(unsigned int *count) { unsigned int cnt, inpr; + DEFINE_WAIT(wait); for (;;) { + prepare_to_wait(&wakeup_count_wait_queue, &wait, + TASK_INTERRUPTIBLE); split_counters(&cnt, &inpr); if (inpr == 0 || signal_pending(current)) break; pm_wakeup_update_hit_counts(); - schedule_timeout_interruptible(msecs_to_jiffies(TIMEOUT)); + + schedule(); } + finish_wait(&wakeup_count_wait_queue, &wait); split_counters(&cnt, &inpr); *count = cnt; -- 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/