From mboxrd@z Thu Jan  1 00:00:00 1970
From: NeilBrown <neilb-l3A5Bk7waGM@public.gmane.org>
Subject: Re: [Bug #32982] Kernel locks up a few minutes after boot
Date: Mon, 18 Apr 2011 08:20:52 +1000
Message-ID: <20110418082052.07476d4a@notabene.brown>
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To: Bart Van Assche <bvanassche-HInyCGIudOg@public.gmane.org>
Cc: Linus Torvalds <torvalds-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>, "Rafael J. Wysocki" <rjw-KKrjLPT3xs0@public.gmane.org>, Linux Kernel Mailing List <linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>, Kernel Testers List <kernel-testers-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>, Maciej Rutecki <maciej.rutecki-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>, Florian Mickler <florian-sVu6HhrpSfRAfugRpC6u6w@public.gmane.org>, Jens Axboe <jaxboe-5c4llco8/ftWk0Htik3J/w@public.gmane.org>

On Mon, 18 Apr 2011 07:07:11 +1000 NeilBrown <neilb-l3A5Bk7waGM@public.gmane.org> wrote:

> On Sun, 17 Apr 2011 20:37:39 +0200 Bart Van Assche <bvanassche-y/PYEvSCHaw@public.gmane.org=
g> wrote:
>=20
> > On Sun, Apr 17, 2011 at 7:03 PM, Linus Torvalds
> > <torvalds-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org> wrote:
> > > On Sun, Apr 17, 2011 at 5:57 AM, Rafael J. Wysocki <rjw-KKrjLPT3xs0@public.gmane.org> =
wrote:
> > > > This message has been generated automatically as a part of a su=
mmary report
> > > > of recent regressions.
> > > >
> > > > The following bug entry is on the current list of known regress=
ions
> > > > from 2.6.38. =A0Please verify if it still should be listed and =
let the tracking team
> > > > know (either way).
> > > >
> > > >
> > > > Bug-Entry =A0 =A0 =A0 : http://bugzilla.kernel.org/show_bug.cgi=
?id=3D32982
> > > > Subject =A0 =A0 =A0 =A0 : Kernel locks up a few minutes after b=
oot
> > > > Submitter =A0 =A0 =A0 : Bart Van Assche <bart.vanassche@gmail.c=
om>
> > > > Date =A0 =A0 =A0 =A0 =A0 =A0: 2011-04-10 19:55 (8 days old)
> > >
> > > Is this machine running a RAID5 setup or something like that?
> > >
> > > There is a known interaction with the new block layer plugging co=
de
> > > and MD. The "hung task" report in that bugzilla looks very much l=
ike
> > > that issue. And you do have "root=3D/dev/md0", so clearly there's=
 some
> > > md thing going on.
> > >
> > > And bisecting might not work all that well for it, because I susp=
ect
> > > it ends up being very much a matter of IO patterns how it trigger=
s.
> > >
> > > Neil supposedly has a patch for it, but I haven't seen it yet. Ne=
il, Jens?
> >=20
> > (converted top-posting into bottom-posting)
> >=20
> > Hello Linus,
> >=20
> > On the system on which bug #32982 has been triggered md0, md1 and m=
d2
> > have been configured as two-disk RAID1 (mirroring).
>=20
> If any of those have write-intent bitmaps then I definitely know what=
 the
> problem is and I'll be posting patches later today (probably not much=
 later).
>=20

Actually it won't be today.  The new block device plugging is still unu=
sable
for MD - so I won't be able to fix this until that gets sorted out.

NeilBrown