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From: Michal Hocko <mhocko@kernel.org>
To: Yang Shi <yang.shi@linux.alibaba.com>
Cc: akpm@linux-foundation.org, linux-mm@kvack.org,
	linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH 1/8] mm: mmap: unmap large mapping by section
Date: Wed, 21 Mar 2018 14:14:49 +0100	[thread overview]
Message-ID: <20180321131449.GN23100@dhcp22.suse.cz> (raw)
In-Reply-To: <1521581486-99134-2-git-send-email-yang.shi@linux.alibaba.com>

On Wed 21-03-18 05:31:19, Yang Shi wrote:
> When running some mmap/munmap scalability tests with large memory (i.e.
> > 300GB), the below hung task issue may happen occasionally.
> 
> INFO: task ps:14018 blocked for more than 120 seconds.
>        Tainted: G            E 4.9.79-009.ali3000.alios7.x86_64 #1
>  "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this
> message.
>  ps              D    0 14018      1 0x00000004
>   ffff885582f84000 ffff885e8682f000 ffff880972943000 ffff885ebf499bc0
>   ffff8828ee120000 ffffc900349bfca8 ffffffff817154d0 0000000000000040
>   00ffffff812f872a ffff885ebf499bc0 024000d000948300 ffff880972943000
>  Call Trace:
>   [<ffffffff817154d0>] ? __schedule+0x250/0x730
>   [<ffffffff817159e6>] schedule+0x36/0x80
>   [<ffffffff81718560>] rwsem_down_read_failed+0xf0/0x150
>   [<ffffffff81390a28>] call_rwsem_down_read_failed+0x18/0x30
>   [<ffffffff81717db0>] down_read+0x20/0x40
>   [<ffffffff812b9439>] proc_pid_cmdline_read+0xd9/0x4e0

Slightly off-topic:
Btw. this sucks as well. Do we really need to take mmap_sem here? Do any
of
	arg_start = mm->arg_start;
	arg_end = mm->arg_end;
	env_start = mm->env_start;
	env_end = mm->env_end;

change after exec or while the pid is already visible in proc? If yes
maybe we can use a dedicated lock.
-- 
Michal Hocko
SUSE Labs

  parent reply	other threads:[~2018-03-21 13:14 UTC|newest]

Thread overview: 41+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-03-20 21:31 [RFC PATCH 0/8] Drop mmap_sem during unmapping large map Yang Shi
2018-03-20 21:31 ` [RFC PATCH 1/8] mm: mmap: unmap large mapping by section Yang Shi
2018-03-21 13:08   ` Michal Hocko
2018-03-21 16:31     ` Yang Shi
2018-03-21 17:29       ` Matthew Wilcox
2018-03-21 21:45         ` Yang Shi
2018-03-21 22:15           ` Matthew Wilcox
2018-03-21 22:40             ` Yang Shi
2018-03-21 22:46           ` Matthew Wilcox
2018-03-22 15:32             ` Laurent Dufour
2018-03-22 15:40               ` Matthew Wilcox
2018-03-22 15:54                 ` Laurent Dufour
2018-03-22 16:05                   ` Matthew Wilcox
2018-03-22 16:18                     ` Laurent Dufour
2018-03-22 16:46                       ` Yang Shi
2018-03-23 13:03                         ` Laurent Dufour
2018-03-22 16:51                       ` Matthew Wilcox
2018-03-22 16:49                     ` Yang Shi
2018-03-22 17:34         ` Yang Shi
2018-03-22 18:48           ` Matthew Wilcox
2018-03-24 18:24         ` Jerome Glisse
2018-03-21 13:14   ` Michal Hocko [this message]
2018-03-21 16:50     ` Yang Shi
2018-03-21 17:16       ` Yang Shi
2018-03-21 21:23         ` Michal Hocko
2018-03-21 22:36           ` Yang Shi
2018-03-22  9:10             ` Michal Hocko
2018-03-22 16:06               ` Yang Shi
2018-03-22 16:12                 ` Michal Hocko
2018-03-22 16:13                 ` Matthew Wilcox
2018-03-22 16:28                   ` Laurent Dufour
2018-03-22 16:36                     ` David Laight
2018-03-20 21:31 ` [RFC PATCH 2/8] mm: mmap: pass atomic parameter to do_munmap() call sites Yang Shi
2018-03-20 21:31 ` [RFC PATCH 3/8] mm: mremap: pass atomic parameter to do_munmap() Yang Shi
2018-03-20 21:31 ` [RFC PATCH 4/8] mm: nommu: add " Yang Shi
2018-03-20 21:31 ` [RFC PATCH 5/8] ipc: shm: pass " Yang Shi
2018-03-20 21:31 ` [RFC PATCH 6/8] fs: proc/vmcore: " Yang Shi
2018-03-20 21:31 ` [RFC PATCH 7/8] x86: mpx: " Yang Shi
2018-03-20 22:35   ` Thomas Gleixner
2018-03-21 16:53     ` Yang Shi
2018-03-20 21:31 ` [RFC PATCH 8/8] x86: vma: " Yang Shi

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