Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758136Ab0FORYU (ORCPT ); Tue, 15 Jun 2010 13:24:20 -0400 Received: from ist.d-labs.de ([213.239.218.44]:39613 "EHLO mx01.d-labs.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753832Ab0FORYS (ORCPT ); Tue, 15 Jun 2010 13:24:18 -0400 Date: Tue, 15 Jun 2010 19:23:47 +0200 From: Florian Mickler To: James Bottomley Cc: Frederic Weisbecker , Jonathan Corbet , markgross@thegnar.org, linville@tuxdriver.com, linux-kernel@vger.kernel.org, pm list , Thomas Gleixner Subject: Re: [PATCH 3/3] pm_qos: only schedule work when in interrupt context Message-ID: <20100615192347.761f427a@schatten.dmk.lab> In-Reply-To: <1276526800-12362-3-git-send-email-florian@mickler.org> References: <1276266352.2862.70.camel@mulgrave.site> <1276526800-12362-3-git-send-email-florian@mickler.org> X-Mailer: Claws Mail 3.7.5 (GTK+ 2.18.9; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2234 Lines: 64 Hi James! On Mon, 14 Jun 2010 16:46:40 +0200 florian@mickler.org wrote: > With this patch we only schedule the work when in interrupt context. > > Before update_request was callable from interrupt-context there was a > 1:1 relation between a change in the request-value and a notification. > This patch restores that behaviour for all constraints that have update_request > never called from interrupt context. > > The notifier mutex serializes calls to blocking_notifier_call_chain, so > that we are serialized against any pending or currently executing notification. > > Signed-off-by: Florian Mickler > --- > kernel/pm_qos_params.c | 10 +++++++--- > 1 files changed, 7 insertions(+), 3 deletions(-) > > diff --git a/kernel/pm_qos_params.c b/kernel/pm_qos_params.c > index 9346906..c06cae9 100644 > --- a/kernel/pm_qos_params.c > +++ b/kernel/pm_qos_params.c > @@ -152,11 +152,15 @@ static s32 min_compare(s32 v1, s32 v2) > static void pm_qos_call_notifiers(struct pm_qos_object *o, > unsigned long curr_value) > { > - schedule_work(&o->notify); > - > if (o->atomic_notifiers) > atomic_notifier_call_chain(o->atomic_notifiers, > - curr_value, NULL); > + (unsigned long) curr_value, NULL); > + > + if (in_interrupt()) > + schedule_work(&o->notify); > + else > + blocking_notifier_call_chain(o->blocking_notifiers, > + (unsigned long) curr_value, NULL); > } > > static void update_notify(struct work_struct *work) What about this? Is this ok? I don't know if it is benign to use in_interrupt() here. I took this idea from the execute_in_process_context() implementation. If this is ok, should I rebase them on your two pm_qos patches (plists and the kzalloc removal)? Did you already thought about some debugging stuff that would suffice the android needs? I kind of thought about either registerieng some notifier callback or using the perf/tracing infrastructure. But I have not looked into it yet. Cheers, Flo -- 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/