From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755839Ab2GRTl7 (ORCPT ); Wed, 18 Jul 2012 15:41:59 -0400 Received: from ogre.sisk.pl ([193.178.161.156]:46786 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753290Ab2GRTlz (ORCPT ); Wed, 18 Jul 2012 15:41:55 -0400 From: "Rafael J. Wysocki" To: Todd Poynor Subject: Re: [PATCH] PM / Sleep: Print name of wakeup source that aborts suspend Date: Wed, 18 Jul 2012 21:47:34 +0200 User-Agent: KMail/1.13.6 (Linux/3.5.0-rc5+; KDE/4.6.0; x86_64; ; ) Cc: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, arve@android.com References: <1342637519-22355-1-git-send-email-toddpoynor@google.com> In-Reply-To: <1342637519-22355-1-git-send-email-toddpoynor@google.com> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-2" Content-Transfer-Encoding: 7bit Message-Id: <201207182147.34750.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wednesday, July 18, 2012, Todd Poynor wrote: > Print active wakeup sources, or the most recently active wakeup > source, when a PM transition is aborted due to wakeup source > events. > > Signed-off-by: Todd Poynor > --- > drivers/base/power/wakeup.c | 29 +++++++++++++++++++++++++++++ > 1 files changed, 29 insertions(+), 0 deletions(-) > > A driver or app may repeatedly request a wakeup source while the system > is attempting to enter suspend, which may indicate a bug or at least > point out a highly active system component that is responsible for > decreased battery life on a mobile device. Even when the incidence > of suspend abort is not severe, identifying wakeup sources that > frequently abort suspend can be a useful clue for power management > analysis. > > In some cases the existing stats can point out the offender where there is > an unexpectedly high activation count that stands out from the others, but > in other cases the wakeup source frequently taken just after the rest of > the system thinks its time to suspend might not stand out in the overall > stats. > > It is also often useful to have information about what's been happening > recently, rather than totals of all activity for the system boot. > > It's suggested to (optionally?) dump a line about which wakeup source > aborted suspend to aid analysis of these situations. > > diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c > index cbb463b..c079ffe 100644 > --- a/drivers/base/power/wakeup.c > +++ b/drivers/base/power/wakeup.c > @@ -649,6 +649,31 @@ void pm_wakeup_event(struct device *dev, unsigned int msec) > } > EXPORT_SYMBOL_GPL(pm_wakeup_event); > > +static void print_active_wakeup_sources(void) > +{ > + struct wakeup_source *ws; > + int active = 0; > + struct wakeup_source *last_activity_ws = NULL; > + > + rcu_read_lock(); > + list_for_each_entry_rcu(ws, &wakeup_sources, entry) { > + if (ws->active) { > + pr_info("active wakeup source: %s\n", ws->name); > + active = 1; Can we do a break here? Or do we want to get all of them? > + } else if (!active && > + (!last_activity_ws || > + ws->last_time.tv64 > > + last_activity_ws->last_time.tv64)) { ktime_to_ns() anyone? > + last_activity_ws = ws; > + } > + } > + > + if (!active && last_activity_ws) > + pr_info("last active wakeup source: %s\n", > + last_activity_ws->name); > + rcu_read_unlock(); > +} > + > /** > * pm_wakeup_pending - Check if power transition in progress should be aborted. > * > @@ -671,6 +696,10 @@ bool pm_wakeup_pending(void) > events_check_enabled = !ret; > } > spin_unlock_irqrestore(&events_lock, flags); > + > + if (ret) > + print_active_wakeup_sources(); > + > return ret; > } There is no way this or equivalent can go into v3.6. It may go into v3.7, but there's a plenty of time for that. Thanks, Rafael