From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([209.51.188.92]:58784)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <peter.maydell@linaro.org>) id 1gybt5-0004ro-U7
	for qemu-devel@nongnu.org; Tue, 26 Feb 2019 07:31:08 -0500
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <peter.maydell@linaro.org>) id 1gybt4-00025o-0Z
	for qemu-devel@nongnu.org; Tue, 26 Feb 2019 07:31:07 -0500
Received: from mail-oi1-x22d.google.com ([2607:f8b0:4864:20::22d]:44319)
	by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16)
	(Exim 4.71) (envelope-from <peter.maydell@linaro.org>)
	id 1gybt3-00020f-Nc
	for qemu-devel@nongnu.org; Tue, 26 Feb 2019 07:31:05 -0500
Received: by mail-oi1-x22d.google.com with SMTP id a81so10118308oii.11
	for <qemu-devel@nongnu.org>; Tue, 26 Feb 2019 04:31:01 -0800 (PST)
MIME-Version: 1.0
References: <CAFEAcA-GYE98ceYOHQ5hGwb-Dh8qv=Jvr=EEp_Dk9YLCmQdA4g@mail.gmail.com>
	<CAFEAcA9295VBXHWzraE_ykcD+-1cLOMS158Lyf+gQxzumxV=xA@mail.gmail.com>
	<20190226121700.GF2721@work-vm>
In-Reply-To: <20190226121700.GF2721@work-vm>
From: Peter Maydell <peter.maydell@linaro.org>
Date: Tue, 26 Feb 2019 12:30:49 +0000
Message-ID: <CAFEAcA8fc74k5XKQhmDgv10bk2vyvqZuon395gT0YGhONOF_QA@mail.gmail.com>
Content-Type: text/plain; charset="UTF-8"
Subject: Re: [Qemu-devel] can we disable the migration-test for TCG targets ?
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel/>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: QEMU Developers <qemu-devel@nongnu.org>, Paolo Bonzini <pbonzini@redhat.com>

On Tue, 26 Feb 2019 at 12:17, Dr. David Alan Gilbert
<dgilbert@redhat.com> wrote:
>
> * Peter Maydell (peter.maydell@linaro.org) wrote:
> > Backtrace of process 125450:
> > Thread 6 (Thread 0xfff800012de0b900 (LWP 127434)):
> > #0  0xfff80001034c5cdc in futex_abstimed_wait_cancelable (private=0,
> > abstime=0xfff800012de09f88, expected=0, futex_word=0x10001236574)
> >     at ../sysdeps/unix/sysv/linux/futex-internal.h:205
> > #1  0xfff80001034c5cdc in do_futex_wait (sem=0x3c,
> > abstime=0xfff800012de09f88) at sem_waitcommon.c:111
> > #2  0xfff80001034c5e00 in __new_sem_wait_slow (sem=0x10001236570,
> > abstime=0xfff800012de09f88) at sem_waitcommon.c:181
> > #3  0x000001000091dacc in qemu_sem_timedwait (sem=0x10001236570,
> > ms=<optimized out>) at /home/pm215/qemu/util/qemu-thread-posix.c:289
> > #4  0x000001000078ae28 in migration_thread (opaque=0x100012364a0) at
> > /home/pm215/qemu/migration/migration.c:3125
>
> So migration is still apparently running, it's rate-limiting
> using a timedwait; but 'ms' has been unhelpfully optimised out; could
> it be stuck in here for some reason?

I looked at this from frame 4, and ms is 64. On the other
hand if I tell gdb to 'fin' it doesn't ever leave
futex_abstimed_wait_cancelable(), so I wonder if we're
managing to get the conversion of the relative time into
an absolute deadline wrong somehow ??

thanks
-- PMM