From: Rik van Riel <riel@redhat.com>
To: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>,
Andrew Morton <akpm@linux-foundation.org>,
Dave Hansen <dave.hansen@intel.com>,
Linux-MM <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 1/7] mm: page_alloc: exclude unreclaimable allocations from zone fairness policy
Date: Fri, 13 Dec 2013 10:45:49 -0500 [thread overview]
Message-ID: <52AB2BAD.4080003@redhat.com> (raw)
In-Reply-To: <1386943807-29601-2-git-send-email-mgorman@suse.de>
On 12/13/2013 09:10 AM, Mel Gorman wrote:
> From: Johannes Weiner <hannes@cmpxchg.org>
>
> Dave Hansen noted a regression in a microbenchmark that loops around
> open() and close() on an 8-node NUMA machine and bisected it down to
> 81c0a2bb515f ("mm: page_alloc: fair zone allocator policy"). That
> change forces the slab allocations of the file descriptor to spread
> out to all 8 nodes, causing remote references in the page allocator
> and slab.
>
> The round-robin policy is only there to provide fairness among memory
> allocations that are reclaimed involuntarily based on pressure in each
> zone. It does not make sense to apply it to unreclaimable kernel
> allocations that are freed manually, in this case instantly after the
> allocation, and incur the remote reference costs twice for no reason.
>
> Only round-robin allocations that are usually freed through page
> reclaim or slab shrinking.
>
> Cc: <stable@kernel.org>
> Bisected-by: Dave Hansen <dave.hansen@intel.com>
> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
> Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
--
All rights reversed
--
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:[~2013-12-13 15:45 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-12-13 14:10 [RFC PATCH 0/7] Configurable fair allocation zone policy v2r6 Mel Gorman
2013-12-13 14:10 ` [PATCH 1/7] mm: page_alloc: exclude unreclaimable allocations from zone fairness policy Mel Gorman
2013-12-13 15:45 ` Rik van Riel [this message]
2013-12-13 14:10 ` [PATCH 2/7] mm: page_alloc: Break out zone page aging distribution into its own helper Mel Gorman
2013-12-13 15:46 ` Rik van Riel
2013-12-16 20:16 ` Johannes Weiner
2013-12-13 14:10 ` [PATCH 3/7] mm: page_alloc: Use zone node IDs to approximate locality Mel Gorman
2013-12-16 13:20 ` Rik van Riel
2013-12-16 20:25 ` Johannes Weiner
2013-12-17 11:13 ` Mel Gorman
2013-12-17 15:38 ` Johannes Weiner
2013-12-17 16:08 ` Mel Gorman
2013-12-17 20:11 ` Johannes Weiner
2013-12-17 21:03 ` Mel Gorman
2013-12-17 22:31 ` Johannes Weiner
2013-12-13 14:10 ` [PATCH 4/7] mm: Annotate page cache allocations Mel Gorman
2013-12-16 15:20 ` Rik van Riel
2013-12-13 14:10 ` [PATCH 5/7] mm: page_alloc: Make zone distribution page aging policy configurable Mel Gorman
2013-12-16 19:25 ` Rik van Riel
2013-12-16 20:42 ` Johannes Weiner
2013-12-17 15:29 ` Mel Gorman
2013-12-17 15:54 ` Johannes Weiner
2013-12-17 16:14 ` Mel Gorman
2013-12-17 17:43 ` Johannes Weiner
2013-12-17 21:22 ` Mel Gorman
2013-12-17 22:57 ` Johannes Weiner
2013-12-17 23:24 ` Mel Gorman
2013-12-13 14:10 ` [PATCH 6/7] mm: page_alloc: Only account batch allocations requests that are eligible Mel Gorman
2013-12-16 20:52 ` Johannes Weiner
2013-12-17 11:20 ` Mel Gorman
2013-12-17 15:43 ` Johannes Weiner
2013-12-17 16:06 ` Mel Gorman
2013-12-13 14:10 ` [PATCH 7/7] mm: page_alloc: Default allow file pages to use remote nodes for fair allocation policy Mel Gorman
2013-12-13 17:04 ` Johannes Weiner
2013-12-13 19:20 ` Mel Gorman
2013-12-13 22:15 ` Johannes Weiner
2013-12-17 16:04 ` Mel Gorman
2013-12-16 19:26 ` Rik van Riel
2013-12-17 15:07 ` [RFC PATCH 0/7] Configurable fair allocation zone policy v2r6 Zlatko Calusic
2013-12-17 21:23 ` Mel Gorman
2013-12-21 16:03 ` Zlatko Calusic
2013-12-23 10:26 ` 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=52AB2BAD.4080003@redhat.com \
--to=riel@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=dave.hansen@intel.com \
--cc=hannes@cmpxchg.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mgorman@suse.de \
/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).