From: Rik van Riel <riel@redhat.com>
To: Mel Gorman <mgorman@suse.de>
Cc: Andrea Arcangeli <aarcange@redhat.com>,
linux-mm@kvack.org, Hugh Dickins <hughd@google.com>,
Richard Davies <richard@arachsys.com>,
Shaohua Li <shli@kernel.org>, Rafael Aquini <aquini@redhat.com>
Subject: Re: [PATCH 1/7] mm: remove ZONE_RECLAIM_LOCKED
Date: Thu, 06 Jun 2013 13:37:28 -0400 [thread overview]
Message-ID: <51B0C8D8.7070708@redhat.com> (raw)
In-Reply-To: <20130606090430.GC1936@suse.de>
On 06/06/2013 05:04 AM, Mel Gorman wrote:
> On Wed, Jun 05, 2013 at 05:10:31PM +0200, Andrea Arcangeli wrote:
>> Zone reclaim locked breaks zone_reclaim_mode=1. If more than one
>> thread allocates memory at the same time, it forces a premature
>> allocation into remote NUMA nodes even when there's plenty of clean
>> cache to reclaim in the local nodes.
>>
>> Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
>
> Be aware that after this patch is applied that it is possible to have a
> situation like this
>
> 1. 4 processes running on node 1
> 2. Each process tries to allocate 30% of memory
> 3. Each process reads the full buffer in a loop (stupid, just an example)
>
> In this situation the processes will continually interfere with each
> other until one of them gets migrated to another zone by the scheduler.
This is a very good point.
Andrea, I suspect we will need some kind of safeguard against
this problem.
I can see how ZONE_RECLAIM_LOCKED may not be that safeguard,
but I do not have any good ideas on what it would be.
Should we limit zone reclaim to priority == DEF_PRIORITY, and
fall back if we fail to free enough memory at DEF_PRIORITY?
Does anybody have better ideas?
--
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>
next prev parent reply other threads:[~2013-06-06 17:40 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-05 15:10 [PATCH 0/7] RFC: adding compaction to zone_reclaim_mode > 0 Andrea Arcangeli
2013-06-05 15:10 ` [PATCH 1/7] mm: remove ZONE_RECLAIM_LOCKED Andrea Arcangeli
2013-06-05 19:23 ` Rik van Riel
2013-06-05 20:37 ` KOSAKI Motohiro
2013-06-05 20:51 ` Christoph Lameter
2013-06-05 21:03 ` KOSAKI Motohiro
2013-06-06 14:15 ` Christoph Lameter
2013-06-06 17:17 ` KOSAKI Motohiro
2013-06-06 18:16 ` Christoph Lameter
2013-06-05 21:33 ` Rafael Aquini
2013-06-06 9:04 ` Mel Gorman
2013-06-06 17:37 ` Rik van Riel [this message]
2013-06-14 16:16 ` Rik van Riel
2013-06-17 9:30 ` Mel Gorman
2013-06-17 18:12 ` Rik van Riel
2013-06-26 20:10 ` Andrea Arcangeli
2013-06-05 15:10 ` [PATCH 2/7] mm: compaction: scan all memory with /proc/sys/vm/compact_memory Andrea Arcangeli
2013-06-05 19:34 ` Rik van Riel
2013-06-05 21:39 ` Rafael Aquini
2013-06-06 9:05 ` Mel Gorman
2013-06-05 15:10 ` [PATCH 3/7] mm: compaction: don't depend on kswapd to invoke reset_isolation_suitable Andrea Arcangeli
2013-06-05 19:49 ` Rik van Riel
2013-06-26 20:38 ` Andrea Arcangeli
2013-06-06 9:11 ` Mel Gorman
2013-06-26 20:48 ` Andrea Arcangeli
2013-06-06 12:47 ` Rafael Aquini
2013-06-05 15:10 ` [PATCH 4/7] mm: compaction: reset before initializing the scan cursors Andrea Arcangeli
2013-06-05 20:04 ` Rik van Riel
2013-06-06 9:14 ` Mel Gorman
2013-06-06 12:49 ` Rafael Aquini
2013-06-05 15:10 ` [PATCH 5/7] mm: compaction: increase the high order pages in the watermarks Andrea Arcangeli
2013-06-05 20:18 ` Rik van Riel
2013-06-28 22:14 ` Andrea Arcangeli
2013-06-06 9:19 ` Mel Gorman
2013-06-05 15:10 ` [PATCH 6/7] mm: compaction: export compact_zone_order() Andrea Arcangeli
2013-06-05 20:24 ` Rik van Riel
2013-06-05 15:10 ` [PATCH 7/7] mm: compaction: add compaction to zone_reclaim_mode Andrea Arcangeli
2013-06-05 22:21 ` Rik van Riel
2013-06-06 10:05 ` Mel Gorman
2013-07-11 16:02 ` Andrea Arcangeli
2013-07-12 12:26 ` Hush Bensen
2013-07-12 16:01 ` Andrea Arcangeli
2013-07-12 23:23 ` Hush Bensen
2013-07-15 9:16 ` Andrea Arcangeli
2013-07-12 23:57 ` Hush Bensen
2013-07-15 9:25 ` Andrea Arcangeli
2013-06-06 8:53 ` [PATCH 0/7] RFC: adding compaction to zone_reclaim_mode > 0 Mel Gorman
2013-06-06 10:09 ` 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=51B0C8D8.7070708@redhat.com \
--to=riel@redhat.com \
--cc=aarcange@redhat.com \
--cc=aquini@redhat.com \
--cc=hughd@google.com \
--cc=linux-mm@kvack.org \
--cc=mgorman@suse.de \
--cc=richard@arachsys.com \
--cc=shli@kernel.org \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).