From: "Michael S. Tsirkin" <mst@redhat.com>
To: malc <av1474@comtv.ru>
Cc: Paolo Bonzini <pbonzini@redhat.com>, qemu-devel@nongnu.org
Subject: [Qemu-devel] Re: [PATCH 11/19] use a bottom half to run timers
Date: Tue, 5 Jan 2010 17:23:46 +0200 [thread overview]
Message-ID: <20100105152346.GA29423@redhat.com> (raw)
In-Reply-To: <Pine.LNX.4.64.1001051822580.2183@linmac.oyster.ru>
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<pbonzini@redhat.com>
> > >>>>
> > >>> 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?
> > >> IMO we need that, I am not sure all code is as signal-safe
> > >> as it should be. At least crashes that I saw with winxp install
> > >> seem to be related to signal handling.
> > >>
> > >
> > > Regards,
> > >
> > > Anthony Liguori
> >
>
> --
> mailto:av1474@comtv.ru
next prev parent reply other threads:[~2010-01-05 19:23 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-12-21 8:09 [Qemu-devel] [PATCH 00/19][RFC] Cleanups + split timer handling out of vl.o Paolo Bonzini
2009-12-21 8:09 ` [Qemu-devel] [PATCH 01/19] centralize handling of -icount Paolo Bonzini
2009-12-21 8:09 ` [Qemu-devel] [PATCH 02/19] add qemu_icount_round Paolo Bonzini
2009-12-21 8:09 ` [Qemu-devel] [PATCH 03/19] avoid dubiously clever code in win32_start_timer Paolo Bonzini
2010-01-04 19:34 ` Anthony Liguori
2010-01-04 18:39 ` Paolo Bonzini
2009-12-21 8:09 ` [Qemu-devel] [PATCH 04/19] fix error in win32_rearm_timer Paolo Bonzini
2009-12-21 8:09 ` [Qemu-devel] [PATCH 05/19] only one flag is needed for alarm_timer Paolo Bonzini
2009-12-21 8:09 ` [Qemu-devel] [PATCH 06/19] more alarm timer cleanup Paolo Bonzini
2009-12-21 8:09 ` [Qemu-devel] [PATCH 07/19] add qemu_get_clock_ns Paolo Bonzini
2009-12-21 8:09 ` [Qemu-devel] [PATCH 08/19] move kbd/mouse events to event.c Paolo Bonzini
2010-01-04 20:19 ` Anthony Liguori
2009-12-21 8:09 ` [Qemu-devel] [PATCH 09/19] remove qemu_rearm_alarm_timer from main loop Paolo Bonzini
2009-12-21 8:09 ` [Qemu-devel] [PATCH 10/19] add qemu_bh_scheduled Paolo Bonzini
2009-12-21 8:09 ` [Qemu-devel] [PATCH 11/19] use a bottom half to run timers Paolo Bonzini
2010-01-04 20:24 ` Anthony Liguori
2010-01-04 19:38 ` Jamie Lokier
2010-01-05 8:38 ` Paolo Bonzini
2010-01-04 20:01 ` [Qemu-devel] " Michael S. Tsirkin
2010-01-04 23:54 ` Anthony Liguori
2010-01-05 12:07 ` Michael S. Tsirkin
2010-01-05 15:23 ` malc
2010-01-05 15:23 ` Michael S. Tsirkin [this message]
2010-01-05 15:32 ` malc
2010-01-05 15:33 ` Michael S. Tsirkin
2010-01-05 15:39 ` malc
2010-01-04 20:01 ` Paolo Bonzini
2010-01-04 23:59 ` Anthony Liguori
2010-01-05 12:48 ` Paolo Bonzini
2010-01-05 13:06 ` Anthony Liguori
2010-01-06 1:20 ` Jamie Lokier
2009-12-21 8:09 ` [Qemu-devel] [PATCH 12/19] new function qemu_icount_delta Paolo Bonzini
2009-12-21 8:09 ` [Qemu-devel] [PATCH 13/19] move tcg_has_work to cpu-exec.c and rename it Paolo Bonzini
2009-12-21 8:09 ` [Qemu-devel] [PATCH 14/19] disentangle tcg and deadline calculation Paolo Bonzini
2009-12-21 8:09 ` [Qemu-devel] [PATCH 15/19] do not provide qemu_event_increment if iothread not used Paolo Bonzini
2009-12-21 8:09 ` [Qemu-devel] [PATCH 16/19] tweak qemu_notify_event Paolo Bonzini
2009-12-21 8:09 ` [Qemu-devel] [PATCH 17/19] move vmstate registration of vmstate_timers earlier Paolo Bonzini
2009-12-21 8:09 ` [Qemu-devel] [PATCH 18/19] introduce qemu_clock_enable Paolo Bonzini
2009-12-21 8:09 ` [Qemu-devel] [PATCH 19/19] split out qemu-timer.c Paolo Bonzini
2010-01-04 20:26 ` Anthony Liguori
2010-01-04 19:26 ` [Qemu-devel] [PATCH 00/19][RFC] Cleanups + split timer handling out of vl.o Anthony Liguori
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