From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Garrett Subject: Re: [Bug #12152] Huge wakeups number from i1915 Date: Mon, 8 Dec 2008 12:59:38 +0000 Message-ID: <20081208125938.GB31976@srcf.ucam.org> References: <6VnlupFpCsN.A.2rE.MsEPJB@chimera> <20081207151203.46c01a0d@infradead.org> <1228717448.9677.3.camel@hidalgo> <200812080828.07683.rjw@sisk.pl> Mime-Version: 1.0 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Content-Disposition: inline In-Reply-To: <200812080828.07683.rjw-KKrjLPT3xs0@public.gmane.org> Sender: kernel-testers-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="utf-8" To: "Rafael J. Wysocki" Cc: Yves-Alexis Perez , Arjan van de Ven , Linux Kernel Mailing List , Kernel Testers List On Mon, Dec 08, 2008 at 08:28:07AM +0100, Rafael J. Wysocki wrote: > On Monday, 8 of December 2008, Yves-Alexis Perez wrote: > > On dim, 2008-12-07 at 15:12 -0800, Arjan van de Ven wrote: > > >=20 > > > > > at least in some of the cases where this has been seen the ca= use > > > is > > > > > the following: > > > > > The i915 DRM driver used to do polling for completion, busy > > > > > waiting. It moved to be interrupt driven, which is usually be= tter > > > > > for power, but it will show up as more wakeups in powertop...= =2E > > > >=20 > > > > IOW, this is not a regression? > > >=20 > > > I don't know about this specifc case (not enough information) but= for > > > the case I described it's not a regression. Going to interrupt dr= iven > > > from busy waiting is an improvement not a regression :) > >=20 > > Well, several thousand or more interrupts really seems like a > > regression :). But it seems that's the same thing as the =E2=80=9CI= RQ > > spinning=E2=80=9D (there was a thread on dri-devel about that). > >=20 > > It seems fixed with a patch from Matthew Garrett applied to > > drm-intel/for-airlied but I don't think this has been applied to Li= nus > > master. >=20 > Any pointers to the patch, please? Doesn't ring any bells for me... --=20 Matthew Garrett | mjg59-1xO5oi07KQx4cg9Nei1l7Q@public.gmane.org