From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NSEzz-0003PV-8s for qemu-devel@nongnu.org; Tue, 05 Jan 2010 14:23:23 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1NSEzt-0003Mn-VM for qemu-devel@nongnu.org; Tue, 05 Jan 2010 14:23:22 -0500 Received: from [199.232.76.173] (port=49038 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NSEzt-0003Mh-HC for qemu-devel@nongnu.org; Tue, 05 Jan 2010 14:23:17 -0500 Received: from mx20.gnu.org ([199.232.41.8]:35293) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1NSEzt-0001LG-99 for qemu-devel@nongnu.org; Tue, 05 Jan 2010 14:23:17 -0500 Received: from mx1.redhat.com ([209.132.183.28]) by mx20.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1NSBSH-0001xs-SC for qemu-devel@nongnu.org; Tue, 05 Jan 2010 10:36:22 -0500 Date: Tue, 5 Jan 2010 17:33:08 +0200 From: "Michael S. Tsirkin" Message-ID: <20100105153308.GA29440@redhat.com> References: <1261382970-23251-1-git-send-email-pbonzini@redhat.com> <1261382970-23251-12-git-send-email-pbonzini@redhat.com> <4B424E95.4040806@codemonkey.ws> <20100104200116.GB21311@redhat.com> <4B427FA5.40701@codemonkey.ws> <20100105120744.GE22827@redhat.com> <20100105152346.GA29423@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Subject: [Qemu-devel] Re: [PATCH 11/19] use a bottom half to run timers List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: malc Cc: Paolo Bonzini , qemu-devel@nongnu.org On Tue, Jan 05, 2010 at 06:32:09PM +0300, malc wrote: > On Tue, 5 Jan 2010, Michael S. Tsirkin wrote: > > > On Tue, Jan 05, 2010 at 06:23:34PM +0300, malc wrote: > > > On Tue, 5 Jan 2010, Michael S. Tsirkin wrote: > > > > > > > On Mon, Jan 04, 2010 at 05:54:13PM -0600, Anthony Liguori wrote: > > > > > On 01/04/2010 02:01 PM, Michael S. Tsirkin wrote: > > > > >> On Mon, Jan 04, 2010 at 02:24:53PM -0600, Anthony Liguori wrote: > > > > >> > > > > >>> On 12/21/2009 02:09 AM, Paolo Bonzini wrote: > > > > >>> > > > > >>>> Make the timer subsystem register its own bottom half instead of > > > > >>>> placing the bottom half code in the heart of the main loop. To > > > > >>>> test if an alarm timer is pending, just check if the bottom half is > > > > >>>> scheduled. > > > > >>>> > > > > >>>> Signed-off-by: Paolo Bonzini > > > > >>>> > > > > >>> I'm not a huge fan of this for a couple reasons. The first is that it > > > > >>> introduces a subtle semantic change. Previously, timers always ran > > > > >>> before bottom halves whereas after this change, timers may run after > > > > >>> some bottoms halves but before others. While this should be okay in > > > > >>> principle, in practice, I'm sure it'll introduce regressions. I'd be > > > > >>> very surprised if cris wasn't affected by this. > > > > >>> > > > > >>> But more importantly, I think timer dispatch needs to be part of the > > > > >>> select loop. malc has a git tree that replaces host alarm timers with > > > > >>> select() timeouts. > > > > >>> > > > > >> Where is that tree? > > > > >> > > > > > > > > > > http://repo.or.cz/w/qemu/malc.git mtloop > > > > > > > > Don't seem to see anything there. > > > > malc? > > > > > > Yes? > > > > Do you have a patch to switch from signals to select? If yes could you > > tell me where it is so I can test whether it fixes winxp install > > crashes I see? > > All i have is published at: > http://repo.or.cz/w/qemu/malc.git/shortlog/refs/heads/mtloop > > Specifically: > http://repo.or.cz/w/qemu/malc.git/commit/b99fef4dc2f1ce9d436791b6821cb30e6335ee9b > > A small fix is needed to make it run with KVM though. Hmm, I guess at least iothread needs to be put back for KVM? -- MST