Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753699Ab0FAHHu (ORCPT ); Tue, 1 Jun 2010 03:07:50 -0400 Received: from ist.d-labs.de ([213.239.218.44]:34398 "EHLO mx01.d-labs.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752291Ab0FAHHs convert rfc822-to-8bit (ORCPT ); Tue, 1 Jun 2010 03:07:48 -0400 Date: Tue, 1 Jun 2010 09:07:37 +0200 From: Florian Mickler To: markgross@thegnar.org Cc: 640e9920@gmail.com, "Rafael J. Wysocki" , Arve =?ISO-8859-15?Q?Hj=F8nnev=E5g?= , Alan Stern , Peter Zijlstra , Linux PM , Brian Swetland , Alan Cox , Matthew Garrett , Thomas Gleixner , LKML , Ingo Molnar Subject: Re: [linux-pm] [PATCH 0/8] Suspend block api (version 8) Message-ID: <20100601090737.4bc243d9@schatten.dmk.lab> In-Reply-To: <20100531232617.GF31155@gvim.org> References: <201005312338.55109.rjw@sisk.pl> <20100531232617.GF31155@gvim.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=ISO-8859-15 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4264 Lines: 124 On Mon, 31 May 2010 16:26:17 -0700 mark gross <640e9920@gmail.com> wrote: > On Mon, May 31, 2010 at 11:38:55PM +0200, Rafael J. Wysocki wrote: > > On Monday 31 May 2010, Arve Hj?nnev?g wrote: > > > 2010/5/29 Alan Stern : > > > > On Sat, 29 May 2010, Arve Hj?nnev?g wrote: > > > > > > > >> > In place of in-kernel suspend blockers, there will be a new type of QoS > > > >> > constraint -- call it QOS_EVENTUALLY. It's a very weak constraint, > > > >> > compatible with all cpuidle modes in which runnable threads are allowed > > > >> > to run (which is all of them), but not compatible with suspend. > > > >> > > > > >> This sound just like another API rename. It will work, but given that > > > >> suspend blockers was the name least objectionable last time around, > > > >> I'm not sure what this would solve. > > > > > > > > It's not just a rename. By changing this into a QoS constraint, we > > > > make it more generally useful. Instead of standing on its own, it > > > > becomes part of the PM-QOS framework. > > > > > > > > > > We cannot use the existing pm-qos framework. It is not safe to call > > > from atomic context. > > > > We've just merged a patch that fixed that if I'm not mistaken. Mark, did your > > PM QoS update fix that? > > > > I'm pretty sure it can be called in atomic context, and if its not I'm > sure we can fix that. It can be called in atomic context. I don't > think it was ever a problem to call it in atomic context. The problem it > had was that crappy list of string compares. Thats been fixed. > > --mgross > Well, the register call uses kzalloc. Apart from that I think we're good. The outstanding list traversals can be fixed also. (see below) Cheers, Flo >From 66fdd76f8cc4be722dba3859ddadfe07e7a4b755 Mon Sep 17 00:00:00 2001 From: Florian Mickler Date: Tue, 1 Jun 2010 09:04:26 +0200 Subject: [PATCH] pm_qos: remove unnecessary list-traversal The new extreme_value is only depending on the old extreme_value and the changing value. Signed-off-by: Florian Mickler --- kernel/pm_qos_params.c | 20 ++++++++++++++------ 1 files changed, 14 insertions(+), 6 deletions(-) diff --git a/kernel/pm_qos_params.c b/kernel/pm_qos_params.c index f42d3f7..6618e2c 100644 --- a/kernel/pm_qos_params.c +++ b/kernel/pm_qos_params.c @@ -136,6 +136,16 @@ static s32 min_compare(s32 v1, s32 v2) } +static void update_target_val(int pm_qos_class, s32 val) +{ + s32 extreme_value; + s32 new_value; + extreme_value = atomic_read(&pm_qos_array[pm_qos_class]->target_value); + new_value = pm_qos_array[pm_qos_class]->comparitor(val,extreme_value); + if (extreme_value != new_value) + atomic_set(&pm_qos_array[pm_qos_class]->target_value,new_value); +} + static void update_target(int pm_qos_class) { s32 extreme_value; @@ -227,8 +237,8 @@ struct pm_qos_request_list *pm_qos_add_request(int pm_qos_class, s32 value) spin_lock_irqsave(&pm_qos_lock, flags); list_add(&dep->list, &pm_qos_array[pm_qos_class]->requests.list); + update_target_val(pm_qos_class,dep->value); spin_unlock_irqrestore(&pm_qos_lock, flags); - update_target(pm_qos_class); } return dep; @@ -249,23 +259,21 @@ void pm_qos_update_request(struct pm_qos_request_list *pm_qos_req, s32 new_value) { unsigned long flags; - int pending_update = 0; s32 temp; if (pm_qos_req) { /*guard against callers passing in null */ + int target = pm_qos_req->pm_qos_class; spin_lock_irqsave(&pm_qos_lock, flags); if (new_value == PM_QOS_DEFAULT_VALUE) - temp = pm_qos_array[pm_qos_req->pm_qos_class]->default_value; + temp = pm_qos_array[target]->default_value; else temp = new_value; if (temp != pm_qos_req->value) { - pending_update = 1; pm_qos_req->value = temp; + update_target_val(target,temp); } spin_unlock_irqrestore(&pm_qos_lock, flags); - if (pending_update) - update_target(pm_qos_req->pm_qos_class); } } EXPORT_SYMBOL_GPL(pm_qos_update_request); -- 1.7.1 -- 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/