From: Dietmar Maurer <dietmar@proxmox.com>
To: Sergio Lopez <slp@redhat.com>
Cc: kwolf@redhat.com, "jsnow@redhat.com" <jsnow@redhat.com>,
"qemu-devel@nongnu.org" <qemu-devel@nongnu.org>,
Stefan Hajnoczi <stefanha@redhat.com>,
Max Reitz <mreitz@redhat.com>
Subject: Re: backup transaction with io-thread core dumps
Date: Thu, 26 Mar 2020 10:23:54 +0100 (CET) [thread overview]
Message-ID: <279529502.21.1585214634195@webmail.proxmox.com> (raw)
In-Reply-To: <914048944.11.1585210462162@webmail.proxmox.com>
> > > As mentioned earlier, even a totally simple/normal backup job fails when
> > > using io-threads and the VM is under load. It results in a total
> > > VM freeze!
> > >
> >
> > This is definitely a different issue. I'll take a look at it today.
>
> Thanks. Stefan found a way to avoid that bug with:
>
> https://lists.gnu.org/archive/html/qemu-devel/2020-03/msg07749.html
>
> But there are doubts that this is the correct way to fix it ...
And I just run into another freeze (with Stefans path applied). This time
when I cancel a running backup:
#0 0x00007ffff5cb3916 in __GI_ppoll (fds=0x7fff63d35c40, nfds=2, timeout=<optimized out>, timeout@entry=0x0, sigmask=sigmask@entry=0x0) at ../sysdeps/unix/sysv/linux/ppoll.c:39
#1 0x0000555555c5fcd9 in ppoll (__ss=0x0, __timeout=0x0, __nfds=<optimized out>, __fds=<optimized out>) at /usr/include/x86_64-linux-gnu/bits/poll2.h:77
#2 0x0000555555c5fcd9 in qemu_poll_ns (fds=<optimized out>, nfds=<optimized out>, timeout=timeout@entry=-1) at util/qemu-timer.c:335
#3 0x0000555555c624c1 in fdmon_poll_wait (ctx=0x7fffe8905e80, ready_list=0x7fffffffd2a8, timeout=-1) at util/fdmon-poll.c:79
#4 0x0000555555c61aa7 in aio_poll (ctx=0x7fffe8905e80, blocking=blocking@entry=true) at util/aio-posix.c:589
#5 0x0000555555bc2c83 in bdrv_do_drained_begin (poll=<optimized out>, ignore_bds_parents=false, parent=0x0, recursive=false, bs=0x7fffe8954bc0) at block/io.c:429
#6 0x0000555555bc2c83 in bdrv_do_drained_begin (bs=0x7fffe8954bc0, recursive=<optimized out>, parent=0x0, ignore_bds_parents=<optimized out>, poll=<optimized out>) at block/io.c:395
#7 0x0000555555bb3c37 in blk_drain (blk=0x7fffe8ebcf80) at block/block-backend.c:1617
#8 0x0000555555bb481d in blk_unref (blk=0x7fffe8ebcf80) at block/block-backend.c:473
#9 0x0000555555b6c835 in block_job_free (job=0x7fff64505000) at blockjob.c:89
#10 0x0000555555b6dd19 in job_unref (job=0x7fff64505000) at job.c:360
#11 0x0000555555b6dd19 in job_unref (job=0x7fff64505000) at job.c:352
#12 0x0000555555b6e69a in job_finish_sync (job=job@entry=0x7fff64505000, finish=finish@entry=0x555555b6ec80 <job_cancel_err>, errp=errp@entry=0x0) at job.c:988
#13 0x0000555555b6ec9e in job_cancel_sync (job=job@entry=0x7fff64505000) at job.c:931
...
Any ideas?
prev parent reply other threads:[~2020-03-26 9:24 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-24 11:13 backup transaction with io-thread core dumps Dietmar Maurer
2020-03-24 13:30 ` Dietmar Maurer
2020-03-24 13:33 ` Dietmar Maurer
2020-03-24 13:44 ` John Snow
2020-03-24 14:00 ` Dietmar Maurer
2020-03-24 13:47 ` Max Reitz
2020-03-24 14:02 ` Dietmar Maurer
2020-03-24 16:49 ` Dietmar Maurer
2020-03-25 11:40 ` Stefan Reiter
2020-03-25 12:23 ` Vladimir Sementsov-Ogievskiy
2020-03-25 15:50 ` [PATCH] backup: don't acquire aio_context in backup_clean Stefan Reiter
2020-03-26 5:54 ` Vladimir Sementsov-Ogievskiy
2020-03-26 9:43 ` Stefan Reiter
2020-03-26 12:46 ` Vladimir Sementsov-Ogievskiy
2020-03-26 11:53 ` Sergio Lopez
2020-03-25 8:13 ` backup transaction with io-thread core dumps Sergio Lopez
2020-03-25 11:46 ` Sergio Lopez
2020-03-25 12:29 ` Dietmar Maurer
2020-03-25 12:39 ` Sergio Lopez
2020-03-25 15:40 ` Dietmar Maurer
2020-03-26 7:50 ` Sergio Lopez
2020-03-26 8:14 ` Dietmar Maurer
2020-03-26 9:23 ` Dietmar Maurer [this message]
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