From: Mel Gorman <mgorman@suse.de>
To: Simon Jeons <simon.jeons@gmail.com>
Cc: Linux-MM <linux-mm@kvack.org>, Jiri Slaby <jslaby@suse.cz>,
Valdis Kletnieks <Valdis.Kletnieks@vt.edu>,
Rik van Riel <riel@redhat.com>,
Zlatko Calusic <zcalusic@bitsync.net>,
Johannes Weiner <hannes@cmpxchg.org>,
dormando <dormando@rydia.net>,
Satoru Moriya <satoru.moriya@hds.com>,
Michal Hocko <mhocko@suse.cz>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 01/10] mm: vmscan: Limit the number of pages kswapd reclaims at each priority
Date: Tue, 19 Mar 2013 09:55:15 +0000 [thread overview]
Message-ID: <20130319095514.GA2055@suse.de> (raw)
In-Reply-To: <5147A8EC.5010908@gmail.com>
On Tue, Mar 19, 2013 at 07:53:16AM +0800, Simon Jeons wrote:
> Hi Mel,
> On 03/17/2013 09:04 PM, Mel Gorman wrote:
> >The number of pages kswapd can reclaim is bound by the number of pages it
> >scans which is related to the size of the zone and the scanning priority. In
> >many cases the priority remains low because it's reset every SWAP_CLUSTER_MAX
> >reclaimed pages but in the event kswapd scans a large number of pages it
> >cannot reclaim, it will raise the priority and potentially discard a large
> >percentage of the zone as sc->nr_to_reclaim is ULONG_MAX. The user-visible
> >effect is a reclaim "spike" where a large percentage of memory is suddenly
> >freed. It would be bad enough if this was just unused memory but because
>
> Since there is nr_reclaimed >= nr_to_reclaim check if priority is
> large than DEF_PRIORITY in shrink_lruvec, how can a large percentage
> of memory is suddenly freed happen?
>
Because of the priority checks made in get_scan_count(). Patch 5 has
more detail on why this happens.
--
Mel Gorman
SUSE Labs
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
WARNING: multiple messages have this Message-ID (diff)
From: Mel Gorman <mgorman@suse.de>
To: Simon Jeons <simon.jeons@gmail.com>
Cc: Linux-MM <linux-mm@kvack.org>, Jiri Slaby <jslaby@suse.cz>,
Valdis Kletnieks <Valdis.Kletnieks@vt.edu>,
Rik van Riel <riel@redhat.com>,
Zlatko Calusic <zcalusic@bitsync.net>,
Johannes Weiner <hannes@cmpxchg.org>,
dormando <dormando@rydia.net>,
Satoru Moriya <satoru.moriya@hds.com>,
Michal Hocko <mhocko@suse.cz>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 01/10] mm: vmscan: Limit the number of pages kswapd reclaims at each priority
Date: Tue, 19 Mar 2013 09:55:15 +0000 [thread overview]
Message-ID: <20130319095514.GA2055@suse.de> (raw)
In-Reply-To: <5147A8EC.5010908@gmail.com>
On Tue, Mar 19, 2013 at 07:53:16AM +0800, Simon Jeons wrote:
> Hi Mel,
> On 03/17/2013 09:04 PM, Mel Gorman wrote:
> >The number of pages kswapd can reclaim is bound by the number of pages it
> >scans which is related to the size of the zone and the scanning priority. In
> >many cases the priority remains low because it's reset every SWAP_CLUSTER_MAX
> >reclaimed pages but in the event kswapd scans a large number of pages it
> >cannot reclaim, it will raise the priority and potentially discard a large
> >percentage of the zone as sc->nr_to_reclaim is ULONG_MAX. The user-visible
> >effect is a reclaim "spike" where a large percentage of memory is suddenly
> >freed. It would be bad enough if this was just unused memory but because
>
> Since there is nr_reclaimed >= nr_to_reclaim check if priority is
> large than DEF_PRIORITY in shrink_lruvec, how can a large percentage
> of memory is suddenly freed happen?
>
Because of the priority checks made in get_scan_count(). Patch 5 has
more detail on why this happens.
--
Mel Gorman
SUSE Labs
next prev parent reply other threads:[~2013-03-19 9:55 UTC|newest]
Thread overview: 260+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-17 13:04 [RFC PATCH 0/8] Reduce system disruption due to kswapd Mel Gorman
2013-03-17 13:04 ` Mel Gorman
2013-03-17 13:04 ` [PATCH 01/10] mm: vmscan: Limit the number of pages kswapd reclaims at each priority Mel Gorman
2013-03-17 13:04 ` Mel Gorman
2013-03-18 23:53 ` Simon Jeons
2013-03-18 23:53 ` Simon Jeons
2013-03-19 9:55 ` Mel Gorman [this message]
2013-03-19 9:55 ` Mel Gorman
2013-03-19 10:16 ` Simon Jeons
2013-03-19 10:16 ` Simon Jeons
2013-03-19 10:59 ` Mel Gorman
2013-03-19 10:59 ` Mel Gorman
2013-03-20 16:18 ` Michal Hocko
2013-03-20 16:18 ` Michal Hocko
2013-03-21 0:52 ` Rik van Riel
2013-03-21 0:52 ` Rik van Riel
2013-03-22 0:08 ` Will Huck
2013-03-22 0:08 ` Will Huck
2013-03-21 9:47 ` Mel Gorman
2013-03-21 9:47 ` Mel Gorman
2013-03-21 12:59 ` Michal Hocko
2013-03-21 12:59 ` Michal Hocko
2013-03-21 0:51 ` Rik van Riel
2013-03-21 0:51 ` Rik van Riel
2013-03-21 15:57 ` Johannes Weiner
2013-03-21 15:57 ` Johannes Weiner
2013-03-21 16:47 ` Mel Gorman
2013-03-21 16:47 ` Mel Gorman
2013-03-22 0:05 ` Will Huck
2013-03-22 0:05 ` Will Huck
2013-03-22 3:52 ` Rik van Riel
2013-03-22 3:52 ` Rik van Riel
2013-03-22 3:56 ` Will Huck
2013-03-22 3:56 ` Will Huck
2013-03-22 4:59 ` Will Huck
2013-03-22 4:59 ` Will Huck
2013-03-22 13:01 ` Rik van Riel
2013-03-22 13:01 ` Rik van Riel
2013-04-05 0:05 ` Will Huck
2013-04-05 0:05 ` Will Huck
2013-04-07 7:32 ` Will Huck
2013-04-07 7:32 ` Will Huck
2013-04-07 7:35 ` Will Huck
2013-04-07 7:35 ` Will Huck
2013-04-11 5:54 ` Will Huck
2013-04-11 5:54 ` Will Huck
2013-04-11 5:58 ` Will Huck
2013-04-11 5:58 ` Will Huck
2013-04-12 5:46 ` Ric Mason
2013-04-12 5:46 ` Ric Mason
2013-04-12 9:34 ` Mel Gorman
2013-04-12 9:34 ` Mel Gorman
2013-04-12 13:40 ` Rik van Riel
2013-04-12 13:40 ` Rik van Riel
2013-03-25 9:07 ` Michal Hocko
2013-03-25 9:07 ` Michal Hocko
2013-03-25 9:13 ` Jiri Slaby
2013-03-25 9:13 ` Jiri Slaby
2013-03-28 22:31 ` Jiri Slaby
2013-03-28 22:31 ` Jiri Slaby
2013-03-29 8:22 ` Michal Hocko
2013-03-29 8:22 ` Michal Hocko
2013-03-30 22:07 ` Jiri Slaby
2013-03-30 22:07 ` Jiri Slaby
2013-04-02 11:15 ` Mel Gorman
2013-04-02 11:15 ` Mel Gorman
2013-03-17 13:04 ` [PATCH 02/10] mm: vmscan: Obey proportional scanning requirements for kswapd Mel Gorman
2013-03-17 13:04 ` Mel Gorman
2013-03-17 14:39 ` Andi Kleen
2013-03-17 14:39 ` Andi Kleen
2013-03-17 15:08 ` Mel Gorman
2013-03-17 15:08 ` Mel Gorman
2013-03-21 1:10 ` Rik van Riel
2013-03-21 1:10 ` Rik van Riel
2013-03-21 9:54 ` Mel Gorman
2013-03-21 9:54 ` Mel Gorman
2013-03-21 14:01 ` Michal Hocko
2013-03-21 14:01 ` Michal Hocko
2013-03-21 14:31 ` Mel Gorman
2013-03-21 14:31 ` Mel Gorman
2013-03-21 15:07 ` Michal Hocko
2013-03-21 15:07 ` Michal Hocko
2013-03-21 15:34 ` Mel Gorman
2013-03-21 15:34 ` Mel Gorman
2013-03-22 7:54 ` Michal Hocko
2013-03-22 7:54 ` Michal Hocko
2013-03-22 8:37 ` Mel Gorman
2013-03-22 8:37 ` Mel Gorman
2013-03-22 10:04 ` Michal Hocko
2013-03-22 10:04 ` Michal Hocko
2013-03-22 10:47 ` Michal Hocko
2013-03-22 10:47 ` Michal Hocko
2013-03-21 16:25 ` Johannes Weiner
2013-03-21 16:25 ` Johannes Weiner
2013-03-21 18:02 ` Mel Gorman
2013-03-21 18:02 ` Mel Gorman
2013-03-22 16:53 ` Johannes Weiner
2013-03-22 16:53 ` Johannes Weiner
2013-03-22 18:25 ` Mel Gorman
2013-03-22 18:25 ` Mel Gorman
2013-03-22 19:09 ` Johannes Weiner
2013-03-22 19:09 ` Johannes Weiner
2013-03-22 19:46 ` Mel Gorman
2013-03-22 19:46 ` Mel Gorman
2013-03-17 13:04 ` [PATCH 03/10] mm: vmscan: Flatten kswapd priority loop Mel Gorman
2013-03-17 13:04 ` Mel Gorman
2013-03-17 14:36 ` Andi Kleen
2013-03-17 14:36 ` Andi Kleen
2013-03-17 15:09 ` Mel Gorman
2013-03-17 15:09 ` Mel Gorman
2013-03-18 7:02 ` Hillf Danton
2013-03-19 10:01 ` Mel Gorman
2013-03-18 23:58 ` Simon Jeons
2013-03-18 23:58 ` Simon Jeons
2013-03-19 10:12 ` Mel Gorman
2013-03-19 10:12 ` Mel Gorman
2013-03-19 3:08 ` Simon Jeons
2013-03-19 3:08 ` Simon Jeons
2013-03-19 8:23 ` Michal Hocko
2013-03-19 8:23 ` Michal Hocko
2013-03-19 10:14 ` Mel Gorman
2013-03-19 10:14 ` Mel Gorman
2013-03-19 10:26 ` Simon Jeons
2013-03-19 10:26 ` Simon Jeons
2013-03-19 11:01 ` Mel Gorman
2013-03-19 11:01 ` Mel Gorman
2013-03-21 14:54 ` Michal Hocko
2013-03-21 14:54 ` Michal Hocko
2013-03-21 15:26 ` Mel Gorman
2013-03-21 15:26 ` Mel Gorman
2013-03-21 15:38 ` Michal Hocko
2013-03-21 15:38 ` Michal Hocko
2013-03-17 13:04 ` [PATCH 04/10] mm: vmscan: Decide whether to compact the pgdat based on reclaim progress Mel Gorman
2013-03-17 13:04 ` Mel Gorman
2013-03-18 11:11 ` Wanpeng Li
2013-03-18 11:11 ` Wanpeng Li
2013-03-19 10:19 ` Mel Gorman
2013-03-19 10:19 ` Mel Gorman
2013-03-18 11:35 ` Hillf Danton
2013-03-18 11:35 ` Hillf Danton
2013-03-19 10:27 ` Mel Gorman
2013-03-19 10:27 ` Mel Gorman
2013-03-21 15:32 ` Michal Hocko
2013-03-21 15:32 ` Michal Hocko
2013-03-21 15:47 ` Mel Gorman
2013-03-21 15:47 ` Mel Gorman
2013-03-21 15:50 ` Michal Hocko
2013-03-21 15:50 ` Michal Hocko
2013-03-17 13:04 ` [PATCH 05/10] mm: vmscan: Do not allow kswapd to scan at maximum priority Mel Gorman
2013-03-17 13:04 ` Mel Gorman
2013-03-21 1:20 ` Rik van Riel
2013-03-21 1:20 ` Rik van Riel
2013-03-21 10:12 ` Mel Gorman
2013-03-21 10:12 ` Mel Gorman
2013-03-21 12:30 ` Rik van Riel
2013-03-21 12:30 ` Rik van Riel
2013-03-21 15:48 ` Michal Hocko
2013-03-21 15:48 ` Michal Hocko
2013-03-17 13:04 ` [PATCH 06/10] mm: vmscan: Have kswapd writeback pages based on dirty pages encountered, not priority Mel Gorman
2013-03-17 13:04 ` Mel Gorman
2013-03-17 14:42 ` Andi Kleen
2013-03-17 14:42 ` Andi Kleen
2013-03-17 15:11 ` Mel Gorman
2013-03-17 15:11 ` Mel Gorman
2013-03-21 17:53 ` Rik van Riel
2013-03-21 17:53 ` Rik van Riel
2013-03-21 18:15 ` Mel Gorman
2013-03-21 18:15 ` Mel Gorman
2013-03-21 18:21 ` Rik van Riel
2013-03-21 18:21 ` Rik van Riel
2013-03-18 11:08 ` Wanpeng Li
2013-03-19 10:35 ` Mel Gorman
2013-03-19 10:35 ` Mel Gorman
2013-03-18 11:08 ` Wanpeng Li
2013-03-17 13:04 ` [PATCH 07/10] mm: vmscan: Block kswapd if it is encountering pages under writeback Mel Gorman
2013-03-17 13:04 ` Mel Gorman
2013-03-17 14:49 ` Andi Kleen
2013-03-17 14:49 ` Andi Kleen
2013-03-17 15:19 ` Mel Gorman
2013-03-17 15:19 ` Mel Gorman
2013-03-17 15:40 ` Andi Kleen
2013-03-17 15:40 ` Andi Kleen
2013-03-19 11:06 ` Mel Gorman
2013-03-19 11:06 ` Mel Gorman
2013-03-18 11:37 ` Simon Jeons
2013-03-18 11:37 ` Simon Jeons
2013-03-19 10:57 ` Mel Gorman
2013-03-19 10:57 ` Mel Gorman
2013-03-18 11:58 ` Wanpeng Li
2013-03-18 11:58 ` Wanpeng Li
2013-03-19 10:58 ` Mel Gorman
2013-03-19 10:58 ` Mel Gorman
2013-03-21 16:32 ` [PATCH 07/10 -v2r1] " Michal Hocko
2013-03-21 16:32 ` Michal Hocko
2013-03-21 18:42 ` [PATCH 07/10] " Rik van Riel
2013-03-21 18:42 ` Rik van Riel
2013-03-22 8:27 ` Mel Gorman
2013-03-22 8:27 ` Mel Gorman
2013-03-17 13:04 ` [PATCH 08/10] mm: vmscan: Have kswapd shrink slab only once per priority Mel Gorman
2013-03-17 13:04 ` Mel Gorman
2013-03-17 14:53 ` Andi Kleen
2013-03-17 14:53 ` Andi Kleen
2013-03-21 16:47 ` Michal Hocko
2013-03-21 16:47 ` Michal Hocko
2013-03-21 19:47 ` Rik van Riel
2013-03-21 19:47 ` Rik van Riel
2013-04-09 6:53 ` Joonsoo Kim
2013-04-09 6:53 ` Joonsoo Kim
2013-04-09 8:41 ` Simon Jeons
2013-04-09 8:41 ` Simon Jeons
2013-04-09 11:13 ` Mel Gorman
2013-04-09 11:13 ` Mel Gorman
2013-04-10 1:07 ` Dave Chinner
2013-04-10 1:07 ` Dave Chinner
2013-04-10 5:23 ` Joonsoo Kim
2013-04-10 5:23 ` Joonsoo Kim
2013-04-11 9:53 ` Mel Gorman
2013-04-11 9:53 ` Mel Gorman
2013-04-10 5:21 ` Joonsoo Kim
2013-04-10 5:21 ` Joonsoo Kim
2013-04-11 10:01 ` Mel Gorman
2013-04-11 10:01 ` Mel Gorman
2013-04-11 10:29 ` Ric Mason
2013-04-11 10:29 ` Ric Mason
2013-03-17 13:04 ` [PATCH 09/10] mm: vmscan: Check if kswapd should writepage " Mel Gorman
2013-03-17 13:04 ` Mel Gorman
2013-03-21 16:58 ` Michal Hocko
2013-03-21 16:58 ` Michal Hocko
2013-03-21 18:07 ` Mel Gorman
2013-03-21 18:07 ` Mel Gorman
2013-03-21 19:52 ` Rik van Riel
2013-03-21 19:52 ` Rik van Riel
2013-03-17 13:04 ` [PATCH 10/10] mm: vmscan: Move logic from balance_pgdat() to kswapd_shrink_zone() Mel Gorman
2013-03-17 13:04 ` Mel Gorman
2013-03-17 14:55 ` Andi Kleen
2013-03-17 14:55 ` Andi Kleen
2013-03-17 15:25 ` Mel Gorman
2013-03-17 15:25 ` Mel Gorman
2013-03-21 17:18 ` Michal Hocko
2013-03-21 17:18 ` Michal Hocko
2013-03-21 18:13 ` Mel Gorman
2013-03-21 18:13 ` Mel Gorman
2013-03-21 10:44 ` [RFC PATCH 0/8] Reduce system disruption due to kswapd Damien Wyart
2013-03-21 10:54 ` Zlatko Calusic
2013-03-21 11:48 ` Mel Gorman
2013-03-21 11:20 ` Mel Gorman
2013-03-22 14:37 ` Mel Gorman
2013-03-22 14:37 ` Mel Gorman
2013-03-24 19:00 ` Jiri Slaby
2013-03-24 19:00 ` Jiri Slaby
2013-03-25 8:17 ` Michal Hocko
2013-03-25 8:17 ` Michal Hocko
-- strict thread matches above, loose matches on Subject: below --
2013-04-09 11:06 [PATCH 0/10] Reduce system disruption due to kswapd V2 Mel Gorman
2013-04-09 11:06 ` [PATCH 01/10] mm: vmscan: Limit the number of pages kswapd reclaims at each priority Mel Gorman
2013-04-09 11:06 ` Mel Gorman
2013-04-09 13:27 ` Michal Hocko
2013-04-09 13:27 ` Michal Hocko
2013-04-10 6:47 ` Kamezawa Hiroyuki
2013-04-10 6:47 ` Kamezawa Hiroyuki
2013-04-11 19:57 [PATCH 0/10] Reduce system disruption due to kswapd V3 Mel Gorman
2013-04-11 19:57 ` [PATCH 01/10] mm: vmscan: Limit the number of pages kswapd reclaims at each priority Mel Gorman
2013-04-11 19:57 ` Mel Gorman
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20130319095514.GA2055@suse.de \
--to=mgorman@suse.de \
--cc=Valdis.Kletnieks@vt.edu \
--cc=dormando@rydia.net \
--cc=hannes@cmpxchg.org \
--cc=jslaby@suse.cz \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@suse.cz \
--cc=riel@redhat.com \
--cc=satoru.moriya@hds.com \
--cc=simon.jeons@gmail.com \
--cc=zcalusic@bitsync.net \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.