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From: Seth Jennings <sjenning@linux.vnet.ibm.com>
To: Jiri Slaby <jslaby@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>,
	Zdenek Kabelac <zkabelac@redhat.com>,
	Valdis.Kletnieks@vt.edu, Jiri Slaby <jirislaby@gmail.com>,
	linux-mm@kvack.org, LKML <linux-kernel@vger.kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Rik van Riel <riel@redhat.com>,
	Robert Jennings <rcj@linux.vnet.ibm.com>
Subject: Re: kswapd0: excessive CPU usage
Date: Thu, 08 Nov 2012 22:22:05 -0600	[thread overview]
Message-ID: <509C84ED.8090605@linux.vnet.ibm.com> (raw)
In-Reply-To: <509422C3.1000803@suse.cz>

On 11/02/2012 02:45 PM, Jiri Slaby wrote:
> On 11/02/2012 11:53 AM, Jiri Slaby wrote:
>> On 11/02/2012 11:44 AM, Zdenek Kabelac wrote:
>>>>> Yes, applying this instead of the revert fixes the issue as well.
>>>
>>> I've applied this patch on 3.7.0-rc3 kernel - and I still see excessive
>>> CPU usage - mainly  after  suspend/resume
>>>
>>> Here is just simple  kswapd backtrace from running kernel:
>>
>> Yup, this is what we were seeing with the former patch only too. Try to
>> apply the other one too:
>> https://patchwork.kernel.org/patch/1673231/
>>
>> For me I would say, it is fixed by the two patches now. I won't be able
>> to report later, since I'm leaving to a conference tomorrow.
> 
> Damn it. It recurred right now, with both patches applied. After I
> started a java program which consumed some more memory. Though there are
> still 2 gigs free, kswap is spinning:
> [<ffffffff810b00da>] __cond_resched+0x2a/0x40
> [<ffffffff811318a0>] shrink_slab+0x1c0/0x2d0
> [<ffffffff8113478d>] kswapd+0x66d/0xb60
> [<ffffffff810a25d0>] kthread+0xc0/0xd0
> [<ffffffff816aa29c>] ret_from_fork+0x7c/0xb0
> [<ffffffffffffffff>] 0xffffffffffffffff

I'm also hitting this issue in v3.7-rc4.  It appears that the last
release not effected by this issue was v3.3.  Bisecting the changes
included for v3.4-rc1 showed that this commit introduced the issue:

fe2c2a106663130a5ab45cb0e3414b52df2fff0c is the first bad commit
commit fe2c2a106663130a5ab45cb0e3414b52df2fff0c
Author: Rik van Riel <riel@redhat.com>
Date:   Wed Mar 21 16:33:51 2012 -0700

    vmscan: reclaim at order 0 when compaction is enabled
...

This is plausible since the issue seems to be in the kswapd + compaction
realm.  I've yet to figure out exactly what about this commit results in
kswapd spinning.

I would be interested if someone can confirm this finding.

--
Seth

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WARNING: multiple messages have this Message-ID (diff)
From: Seth Jennings <sjenning@linux.vnet.ibm.com>
To: Jiri Slaby <jslaby@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>,
	Zdenek Kabelac <zkabelac@redhat.com>,
	Valdis.Kletnieks@vt.edu, Jiri Slaby <jirislaby@gmail.com>,
	linux-mm@kvack.org, LKML <linux-kernel@vger.kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Rik van Riel <riel@redhat.com>,
	Robert Jennings <rcj@linux.vnet.ibm.com>
Subject: Re: kswapd0: excessive CPU usage
Date: Thu, 08 Nov 2012 22:22:05 -0600	[thread overview]
Message-ID: <509C84ED.8090605@linux.vnet.ibm.com> (raw)
In-Reply-To: <509422C3.1000803@suse.cz>

On 11/02/2012 02:45 PM, Jiri Slaby wrote:
> On 11/02/2012 11:53 AM, Jiri Slaby wrote:
>> On 11/02/2012 11:44 AM, Zdenek Kabelac wrote:
>>>>> Yes, applying this instead of the revert fixes the issue as well.
>>>
>>> I've applied this patch on 3.7.0-rc3 kernel - and I still see excessive
>>> CPU usage - mainly  after  suspend/resume
>>>
>>> Here is just simple  kswapd backtrace from running kernel:
>>
>> Yup, this is what we were seeing with the former patch only too. Try to
>> apply the other one too:
>> https://patchwork.kernel.org/patch/1673231/
>>
>> For me I would say, it is fixed by the two patches now. I won't be able
>> to report later, since I'm leaving to a conference tomorrow.
> 
> Damn it. It recurred right now, with both patches applied. After I
> started a java program which consumed some more memory. Though there are
> still 2 gigs free, kswap is spinning:
> [<ffffffff810b00da>] __cond_resched+0x2a/0x40
> [<ffffffff811318a0>] shrink_slab+0x1c0/0x2d0
> [<ffffffff8113478d>] kswapd+0x66d/0xb60
> [<ffffffff810a25d0>] kthread+0xc0/0xd0
> [<ffffffff816aa29c>] ret_from_fork+0x7c/0xb0
> [<ffffffffffffffff>] 0xffffffffffffffff

I'm also hitting this issue in v3.7-rc4.  It appears that the last
release not effected by this issue was v3.3.  Bisecting the changes
included for v3.4-rc1 showed that this commit introduced the issue:

fe2c2a106663130a5ab45cb0e3414b52df2fff0c is the first bad commit
commit fe2c2a106663130a5ab45cb0e3414b52df2fff0c
Author: Rik van Riel <riel@redhat.com>
Date:   Wed Mar 21 16:33:51 2012 -0700

    vmscan: reclaim at order 0 when compaction is enabled
...

This is plausible since the issue seems to be in the kswapd + compaction
realm.  I've yet to figure out exactly what about this commit results in
kswapd spinning.

I would be interested if someone can confirm this finding.

--
Seth


  parent reply	other threads:[~2012-11-09  4:22 UTC|newest]

Thread overview: 100+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-10-11  8:52 kswapd0: wxcessive CPU usage Jiri Slaby
2012-10-11  8:52 ` Jiri Slaby
2012-10-11 13:44 ` Valdis.Kletnieks
2012-10-11 15:34   ` Jiri Slaby
2012-10-11 15:34     ` Jiri Slaby
2012-10-11 17:56     ` Valdis.Kletnieks
2012-10-11 17:59       ` Jiri Slaby
2012-10-11 17:59         ` Jiri Slaby
2012-10-11 18:19         ` Valdis.Kletnieks
2012-10-11 22:08           ` kswapd0: excessive " Jiri Slaby
2012-10-11 22:08             ` Jiri Slaby
2012-10-12 12:37             ` Jiri Slaby
2012-10-12 12:37               ` Jiri Slaby
2012-10-12 13:57               ` Mel Gorman
2012-10-12 13:57                 ` Mel Gorman
2012-10-15  9:54                 ` Jiri Slaby
2012-10-15  9:54                   ` Jiri Slaby
2012-10-15 11:09                   ` Mel Gorman
2012-10-15 11:09                     ` Mel Gorman
2012-10-29 10:52                     ` Thorsten Leemhuis
2012-10-29 10:52                       ` Thorsten Leemhuis
2012-10-30 19:18                       ` Mel Gorman
2012-10-30 19:18                         ` Mel Gorman
2012-10-31 11:25                         ` Thorsten Leemhuis
2012-10-31 11:25                           ` Thorsten Leemhuis
2012-10-31 15:04                           ` Mel Gorman
2012-10-31 15:04                             ` Mel Gorman
2012-11-04 16:36                         ` Rik van Riel
2012-11-04 16:36                           ` Rik van Riel
2012-11-02 10:44                     ` Zdenek Kabelac
2012-11-02 10:44                       ` Zdenek Kabelac
2012-11-02 10:53                       ` Jiri Slaby
2012-11-02 10:53                         ` Jiri Slaby
2012-11-02 19:45                         ` Jiri Slaby
2012-11-02 19:45                           ` Jiri Slaby
2012-11-04 11:26                           ` Zdenek Kabelac
2012-11-04 11:26                             ` Zdenek Kabelac
2012-11-05 14:24                           ` [PATCH] Revert "mm: vmscan: scale number of pages reclaimed by reclaim/compaction based on failures" Mel Gorman
2012-11-05 14:24                             ` Mel Gorman
2012-11-06 10:15                             ` Johannes Hirte
2012-11-06 10:15                               ` Johannes Hirte
2012-11-09  8:36                               ` Mel Gorman
2012-11-09  8:36                                 ` Mel Gorman
2012-11-14 21:43                                 ` Johannes Hirte
2012-11-14 21:43                                   ` Johannes Hirte
2012-11-09  9:12                             ` Mel Gorman
2012-11-09  9:12                               ` Mel Gorman
2012-11-09  4:22                           ` Seth Jennings [this message]
2012-11-09  4:22                             ` kswapd0: excessive CPU usage Seth Jennings
2012-11-09  8:07                             ` Zdenek Kabelac
2012-11-09  8:07                               ` Zdenek Kabelac
2012-11-09  9:06                               ` Mel Gorman
2012-11-09  9:06                                 ` Mel Gorman
2012-11-11  9:13                                 ` Zdenek Kabelac
2012-11-11  9:13                                   ` Zdenek Kabelac
2012-11-12 11:37                                   ` [PATCH] Revert "mm: remove __GFP_NO_KSWAPD" Mel Gorman
2012-11-12 11:37                                     ` Mel Gorman
2012-11-16 19:14                                     ` Josh Boyer
2012-11-16 19:14                                       ` Josh Boyer
2012-11-16 19:51                                       ` Andrew Morton
2012-11-16 19:51                                         ` Andrew Morton
2012-11-20  1:43                                         ` Valdis.Kletnieks
2012-11-16 20:06                                       ` Mel Gorman
2012-11-16 20:06                                         ` Mel Gorman
2012-11-20 15:38                                         ` Josh Boyer
2012-11-20 15:38                                           ` Josh Boyer
2012-11-20 16:13                                           ` Bruno Wolff III
2012-11-20 16:13                                             ` Bruno Wolff III
2012-11-20 17:43                                           ` Thorsten Leemhuis
2012-11-20 17:43                                             ` Thorsten Leemhuis
2012-11-23 15:20                                             ` Thorsten Leemhuis
2012-11-23 15:20                                               ` Thorsten Leemhuis
2012-11-27 11:12                                               ` Mel Gorman
2012-11-27 11:12                                                 ` Mel Gorman
2012-11-21 15:08                                           ` Mel Gorman
2012-11-21 15:08                                             ` Mel Gorman
2012-11-20  9:18                                     ` Glauber Costa
2012-11-20  9:18                                       ` Glauber Costa
2012-11-20 20:18                                       ` Andrew Morton
2012-11-20 20:18                                         ` Andrew Morton
2012-11-21  8:30                                         ` Glauber Costa
2012-11-21  8:30                                           ` Glauber Costa
2012-11-12 12:19                                   ` kswapd0: excessive CPU usage Mel Gorman
2012-11-12 12:19                                     ` Mel Gorman
2012-11-12 13:13                                     ` Zdenek Kabelac
2012-11-12 13:13                                       ` Zdenek Kabelac
2012-11-12 13:31                                       ` Mel Gorman
2012-11-12 13:31                                         ` Mel Gorman
2012-11-12 14:50                                         ` Zdenek Kabelac
2012-11-12 14:50                                           ` Zdenek Kabelac
2012-11-18 19:00                                         ` Zdenek Kabelac
2012-11-18 19:00                                           ` Zdenek Kabelac
2012-11-18 19:07                                           ` Jiri Slaby
2012-11-18 19:07                                             ` Jiri Slaby
2012-11-09  8:40                             ` Mel Gorman
2012-11-09  8:40                               ` Mel Gorman
2012-10-11 22:14 ` kswapd0: wxcessive " Andrew Morton
2012-10-11 22:14   ` Andrew Morton
2012-10-11 22:26   ` Jiri Slaby
2012-10-11 22:26     ` Jiri Slaby

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