From: Mika Westerberg <mika.westerberg@linux.intel.com>
To: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Miklos Szeredi <mszeredi@suse.cz>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>
Subject: Re: fs/dcache.c - BUG: soft lockup - CPU#5 stuck for 22s! [systemd-udevd:1667]
Date: Thu, 29 May 2014 14:04:39 +0300 [thread overview]
Message-ID: <20140529110439.GA2006@lahna.fi.intel.com> (raw)
In-Reply-To: <20140529105107.GB1938@lahna.fi.intel.com>
On Thu, May 29, 2014 at 01:51:07PM +0300, Mika Westerberg wrote:
> On Thu, May 29, 2014 at 06:34:44AM +0100, Al Viro wrote:
> > On Thu, May 29, 2014 at 04:52:33AM +0100, Al Viro wrote:
> > > On Thu, May 29, 2014 at 04:11:49AM +0100, Al Viro wrote:
> > > > On Wed, May 28, 2014 at 07:39:54PM +0100, Al Viro wrote:
> > > >
> > > > > OK, the warnings about averting your eyes very much apply; the thing below
> > > > > definitely needs more massage before it becomes acceptable (and no, it's
> > > > > not a single commit; I'm not that insane), but it changes behaviour in the
> > > > > way described above. Could you check if the livelock persists with it?
> > > > > No trace-generating code in there, so the logs should be compact enough...
> > > >
> > > > Here's an updated patch, hopefully slightly less vomit-inducing. Should
> > > > give the same behaviour as the previous one... Again, it's a cumulative
> > > > diff - I'm still massaging the splitup here.
> > >
> > > BTW, it still leaves the "proceed to parent" case in shrink_dentry_list();
> > > in theory, it's also vulnerable to the same livelock. Can be dealt pretty
> > > much the same way; I'd rather leave that one for right after -final, though,
> > > if the already posted variant turns out to be sufficient...
> >
> > ... which is (presumably) dealt with the incremental I'd just sent to Linus;
> > seeing what kind of dumb mistakes I'm making, I'd better call it quits for
> > tonight - it's 1:30am here and I didn't have anywhere near enough sleep
> > yesterday. I'd appeciate if you could test the patch immediately
> > upthread (from Message-ID: <20140529031149.GE18016@ZenIV.linux.org.uk>)
> > and see if it helps. There's an incremental on top of it (from
> > Message-ID: <20140529052621.GH18016@ZenIV.linux.org.uk>) that might or
> > might not be a good idea.
>
> Thanks for the patch.
>
> I tested patch <20140529031149.GE18016@ZenIV.linux.org.uk> and it seems
> to improve things. After first plug/unplug I can see similar behaviour
> but after a while it recovered. I did several iterations of plug/unplug
> afterwards and didn't see the livelock to trigger.
>
> dmesg is attached.
>
> I'm going to try your incremental patch now.
With your both patches applied the problem is gone :-)
I did 20 plug/unplugs, rebooted the machine and another 20 plug/unplugs
and didn't see the livelock at once.
Thanks a lot!
next prev parent reply other threads:[~2014-05-29 11:04 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-26 9:37 fs/dcache.c - BUG: soft lockup - CPU#5 stuck for 22s! [systemd-udevd:1667] Mika Westerberg
2014-05-26 13:57 ` Al Viro
2014-05-26 14:29 ` Mika Westerberg
2014-05-26 15:27 ` Al Viro
2014-05-26 16:42 ` Al Viro
2014-05-26 18:17 ` Linus Torvalds
2014-05-26 18:26 ` Al Viro
2014-05-26 20:24 ` Linus Torvalds
2014-05-27 1:40 ` Al Viro
2014-05-27 3:14 ` Al Viro
2014-05-27 4:00 ` Al Viro
2014-05-27 7:04 ` Mika Westerberg
2014-05-28 3:19 ` Al Viro
2014-05-28 7:37 ` Mika Westerberg
2014-05-28 11:57 ` Al Viro
2014-05-28 13:11 ` Mika Westerberg
2014-05-28 14:19 ` Al Viro
2014-05-28 18:39 ` Al Viro
2014-05-28 19:43 ` Linus Torvalds
2014-05-28 20:02 ` Linus Torvalds
2014-05-28 20:25 ` Al Viro
2014-05-29 10:42 ` Mika Westerberg
2014-05-28 20:14 ` Al Viro
2014-05-28 21:11 ` Linus Torvalds
2014-05-28 21:28 ` Al Viro
2014-05-29 3:11 ` Al Viro
2014-05-29 3:52 ` Al Viro
2014-05-29 5:34 ` Al Viro
2014-05-29 10:51 ` Mika Westerberg
2014-05-29 11:04 ` Mika Westerberg [this message]
2014-05-29 13:30 ` Al Viro
2014-05-29 14:56 ` Mika Westerberg
2014-05-29 15:10 ` Linus Torvalds
2014-05-29 15:44 ` Al Viro
2014-05-29 16:23 ` Al Viro
2014-05-29 16:29 ` Linus Torvalds
2014-05-29 16:53 ` Al Viro
2014-05-29 18:52 ` Al Viro
2014-05-29 19:14 ` Linus Torvalds
2014-05-30 4:50 ` Al Viro
2014-05-30 5:00 ` Linus Torvalds
2014-05-30 6:49 ` Al Viro
2014-05-30 8:12 ` Mika Westerberg
2014-05-30 15:21 ` Al Viro
2014-05-30 15:31 ` Linus Torvalds
2014-05-30 16:48 ` [git pull] " Al Viro
2014-05-30 17:14 ` Al Viro
2014-05-31 14:18 ` Josh Boyer
2014-05-31 14:48 ` Linus Torvalds
2014-05-31 14:58 ` Josh Boyer
2014-05-31 16:12 ` Josh Boyer
2014-05-30 17:15 ` Sedat Dilek
2014-05-29 4:21 ` Linus Torvalds
2014-05-29 5:16 ` Al Viro
2014-05-29 5:26 ` Al Viro
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