From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: Re: [linux-pm] [PATCH 0/8] Suspend block api (version 8) Date: Fri, 28 May 2010 09:43:43 +0200 Message-ID: <1275032623.32462.30.camel@laptop> References: <20100527181433.GG3543@srcf.ucam.org> <20100527200313.5c532f2f@lxorguk.ukuu.org.uk> <201005280110.17075.rjw@sisk.pl> <20100528005045.6ea5feba@lxorguk.ukuu.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Arve =?ISO-8859-1?Q?Hj=F8nnev=E5g?= Cc: Alan Cox , "Rafael J. Wysocki" , Matthew Garrett , Alan Stern , Thomas Gleixner , Paul@smtp1.linux-foundation.org, LKML , Florian Mickler , Linux OMAP Mailing List , Linux PM List-Id: linux-omap@vger.kernel.org On Thu, 2010-05-27 at 17:45 -0700, Arve Hj=C3=B8nnev=C3=A5g wrote: > What happens if the user presses the button right before you set QoS > of 'user apps' to QS_NONE? > To me it looks like this solution would result in this sequence which > may ignore the button press: > Button pushed > Button driver sets QoS of app it wakes to QS_ABOVESUSPEND > Set QoS of 'user apps' to QS_NONE=20 I don't think we should change app QoS parameters, but change service provider parameters. =46or instance, suppose the filesystem-IO QoS has 3 levels:=20 High, Normal and Idle. Then if we assign Idle to updatedb, we'll service it as long as the filesystem-server QoS has a higher level (High and Normal). When we change the filesystem-serves' QoS to idle, it finds there is nothing to keep it servicing stuff and it'll block pending requests, updatedb stop= s being runnable and we're good.