Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754894AbYHTHYy (ORCPT ); Wed, 20 Aug 2008 03:24:54 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752452AbYHTHYo (ORCPT ); Wed, 20 Aug 2008 03:24:44 -0400 Received: from bombadil.infradead.org ([18.85.46.34]:49548 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752222AbYHTHYn (ORCPT ); Wed, 20 Aug 2008 03:24:43 -0400 Subject: Re: [PATCH] sched: disable hrtick implementation From: Peter Zijlstra To: Justin Madru Cc: Greg KH , Ingo Molnar , lkml , Michal Januszewski , Antonino Daplas , Rafael Wysocki , Romano Giannetti , Adrian Bunk , Jeremy Nickurak In-Reply-To: <48AB4F2B.9070405@gawab.com> References: <48A9BDC0.9070800@gawab.com> <20080819003110.GH9914@elte.hu> <1219127296.10800.357.camel@twins> <20080819092543.GD28713@elte.hu> <1219138380.10800.376.camel@twins> <20080819182222.GA25576@suse.de> <48AB1F49.6040207@gawab.com> <20080819194428.GA9997@suse.de> <48AB4F2B.9070405@gawab.com> Content-Type: text/plain Date: Wed, 20 Aug 2008 09:24:51 +0200 Message-Id: <1219217091.10800.395.camel@twins> Mime-Version: 1.0 X-Mailer: Evolution 2.22.3.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1515 Lines: 43 On Tue, 2008-08-19 at 15:54 -0700, Justin Madru wrote: > The hrtick implementation in 2.6.25 and .26 has been known to cause boot > problems with at least Intel GMA cards. see: > > https://bugs.freedesktop.org/show_bug.cgi?id=15602 > http://bugzilla.kernel.org/show_bug.cgi?id=10892 > > A full fix to hrtick went into 2.6.27 > (31656519e132f6612584815f128c83976a9aaaef), > but that fix is too intrusive to backport. Henceforth, we default to > disable hrtick. Thing is, I'm still not understanding how, or if, the old code is wrong. That said, this will paper over the problem just fine, and as its old kernels we're talking about I don't particularly care. Just occured to me that a Kconfig change that always makes CONFIG_SCHED_HRTICK not set will also do. > Signed-off-by: Justin Madru > Tested-by: Justin Madru > Cc: Peter Zijlstra > Cc: Ingo Molnar > > --- a/kernel/sched_features.h > +++ b/kernel/sched_features.h > @@ -4,7 +4,7 @@ > SCHED_FEAT(AFFINE_WAKEUPS, 1) > SCHED_FEAT(CACHE_HOT_BUDDY, 1) > SCHED_FEAT(SYNC_WAKEUPS, 1) > -SCHED_FEAT(HRTICK, 1) > +SCHED_FEAT(HRTICK, 0) > SCHED_FEAT(DOUBLE_TICK, 0) > SCHED_FEAT(NORMALIZED_SLEEPER, 1) > SCHED_FEAT(DEADLINE, 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/