From: Andrew Morton <akpm@linux-foundation.org>
To: Sasha Levin <levinsasha928@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>,
Hugh Dickins <hughd@google.com>,
Thomas Gleixner <tglx@linutronix.de>,
linux-mm@kvack.org,
"linux-kernel@vger.kernel.org List"
<linux-kernel@vger.kernel.org>, Dave Jones <davej@redhat.com>
Subject: Re: mm: migrate_pages hang
Date: Fri, 30 Mar 2012 15:35:19 -0700 [thread overview]
Message-ID: <20120330153519.1e80735b.akpm@linux-foundation.org> (raw)
In-Reply-To: <CA+1xoqfxZ8cji9SZFg0NZN-riFO7c8tKjtH7W1H9q-ES=J+ybw@mail.gmail.com>
On Sat, 31 Mar 2012 00:23:30 +0200
Sasha Levin <levinsasha928@gmail.com> wrote:
> Hi all,
>
> I saw the following inside a KVM guest, this is the first time I
> observed this hang and it seems to have started with today's
> (20120330) -next.
>
> [ 3122.093136] INFO: task trinity:17328 blocked for more than 120 seconds.
> [ 3122.093807] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
> disables this message.
> [ 3122.095237] trinity D ffff8800703284d8 5648 17328 3101 0x00000004
> [ 3122.096543] ffff8800064cfb08 0000000000000082 ffff8800064cfab8
> ffffffff8107d346
> [ 3122.098087] ffff8800064cffd8 00000000001d4580 ffff8800064ce010
> 00000000001d4580
> [ 3122.099447] 00000000001d4580 00000000001d4580 ffff8800064cffd8
> 00000000001d4580
> [ 3122.100607] Call Trace:
> [ 3122.100983] [<ffffffff8107d346>] ? kvm_clock_read+0x46/0x80
> [ 3122.101950] [<ffffffff81176260>] ? __lock_page+0x70/0x70
> [ 3122.102761] [<ffffffff827063d4>] schedule+0x24/0x70
> [ 3122.103576] [<ffffffff827064a7>] io_schedule+0x87/0xd0
> [ 3122.104371] [<ffffffff81176269>] sleep_on_page+0x9/0x10
> [ 3122.105179] [<ffffffff82704152>] __wait_on_bit_lock+0x52/0xb0
> [ 3122.106042] [<ffffffff81176252>] __lock_page+0x62/0x70
> [ 3122.106811] [<ffffffff810d78f0>] ? autoremove_wake_function+0x40/0x40
> [ 3122.107450] [<ffffffff811cc2f9>] lock_page+0x39/0x40
> [ 3122.107976] [<ffffffff811cd294>] __unmap_and_move+0x274/0x280
> [ 3122.108848] [<ffffffff81899061>] ? list_del+0x11/0x40
> [ 3122.109385] [<ffffffff811cd32d>] unmap_and_move+0x8d/0x130
> [ 3122.109957] [<ffffffff811cd47b>] migrate_pages+0xab/0x150
> [ 3122.110788] [<ffffffff811bc440>] ? isolate_freepages+0x390/0x390
> [ 3122.111399] [<ffffffff811bcc51>] compact_zone+0x1e1/0x2a0
> [ 3122.111935] [<ffffffff82707e15>] ? _raw_spin_unlock_irqrestore+0x75/0xa0
> [ 3122.112579] [<ffffffff811bcec3>] __compact_pgdat+0x1b3/0x200
> [ 3122.113199] [<ffffffff811bcf47>] compact_node+0x37/0x40
> [ 3122.113631] [<ffffffff81185080>] ? lru_add_drain_all+0x10/0x20
> [ 3122.114266] [<ffffffff811bcf98>] sysfs_compact_node+0x48/0x60
> [ 3122.114768] [<ffffffff8125c3d2>] ? sysfs_write_file+0x82/0xf0
> [ 3122.115368] [<ffffffff81b0dc3b>] dev_attr_store+0x1b/0x20
> [ 3122.115877] [<ffffffff8125c3ee>] sysfs_write_file+0x9e/0xf0
> [ 3122.116423] [<ffffffff811e3258>] vfs_write+0xc8/0x190
> [ 3122.116934] [<ffffffff811e340f>] sys_write+0x4f/0x90
> [ 3122.117697] [<ffffffff82708cf9>] system_call_fastpath+0x16/0x1b
> [ 3122.118354] 2 locks held by trinity/17328:
> [ 3122.118694] #0: (&buffer->mutex){+.+.+.}, at:
> [<ffffffff8125c394>] sysfs_write_file+0x44/0xf0
> [ 3122.119498] #1: (s_active#57){.+.+.+}, at: [<ffffffff8125c3d2>]
> sysfs_write_file+0x82/0xf0
You reported what I suppose is the same bug a week ago ("mm: hung task
(handle_pte_fault)"): the kernel is waiting for a page to come
unlocked, thinking that there is I/O outstanding against it.
And my ugh still applies: "There are quite a lot of things which could
cause this, alas. VM, readahead, scheduler, core wait/wakeup code, IO
system, interrupt system (if it happens outside KVM, I guess). So....
ugh. Hopefully someone will hit this in a situation where it can be
narrowed down or bisected."
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next prev parent reply other threads:[~2012-03-30 22:35 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-30 22:23 Sasha Levin
2012-03-30 22:35 ` Andrew Morton [this message]
2012-03-30 22:36 ` Sasha Levin
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