From: Vlastimil Babka <vbabka@suse.cz>
To: Mel Gorman <mgorman@techsingularity.net>,
Andrew Morton <akpm@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>,
Andrea Arcangeli <aarcange@redhat.com>,
Zi Yan <zi.yan@cs.rutgers.edu>, Michal Hocko <mhocko@kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Linux-MM <linux-mm@kvack.org>
Subject: Re: [PATCH 1/5] mm, page_alloc: Spread allocations across zones before introducing fragmentation
Date: Mon, 26 Nov 2018 13:36:57 +0100 [thread overview]
Message-ID: <7a3b2706-8d8c-9233-d6fc-26ace52641e7@suse.cz> (raw)
In-Reply-To: <20181123114528.28802-2-mgorman@techsingularity.net>
On 11/23/18 12:45 PM, Mel Gorman wrote:
...
> Fault latencies are slightly reduced while allocation success rates remain
> at zero as this configuration does not make any special effort to allocate
> THP and fio is heavily active at the time and either filling memory or
> keeping pages resident. However, a 49% reduction of serious fragmentation
> events reduces the changes of external fragmentation being a problem in
> the future.
>
> Vlastimil asked during review for a breakdown of the allocation types
> that are falling back.
>
> vanilla
> 3816 MIGRATE_UNMOVABLE
> 800845 MIGRATE_MOVABLE
> 33 MIGRATE_UNRECLAIMABLE
>
> patch
> 735 MIGRATE_UNMOVABLE
> 408135 MIGRATE_MOVABLE
> 42 MIGRATE_UNRECLAIMABLE
Nit: it's MIGRATE_RECLAIMABLE :)
> The majority of the fallbacks are due to movable allocations and this is
> consistent for the workload throughout the series so will not be presented
> again as the primary source of fallbacks are movable allocations.
Note that I was more interested in the *reduction* of different kinds of
fallbacks, not their ratios - that the majority is caused by movable
allocations is fully expected.
And the results above actually show that while the reduction for MOVABLE
is ~50%, the reduction for UNMOVABLE is actually 80%! IMHO that's great
(better than I would expect, in fact), and good to know.
...
> Overall, the patch reduces the number of external fragmentation causing
> events so the success of THP over long periods of time would be improved
> for this adverse workload.
>
> Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
next prev parent reply other threads:[~2018-11-26 12:37 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-23 11:45 [PATCH 0/5] Fragmentation avoidance improvements v5 Mel Gorman
2018-11-23 11:45 ` [PATCH 1/5] mm, page_alloc: Spread allocations across zones before introducing fragmentation Mel Gorman
2018-11-26 12:36 ` Vlastimil Babka [this message]
2018-11-23 11:45 ` [PATCH 2/5] mm: Move zone watermark accesses behind an accessor Mel Gorman
2018-11-23 11:45 ` [PATCH 3/5] mm: Use alloc_flags to record if kswapd can wake Mel Gorman
2018-11-26 13:38 ` Vlastimil Babka
2018-11-26 14:35 ` [PATCH] mm: Use alloc_flags to record if kswapd can wake -fix Mel Gorman
2018-11-23 11:45 ` [PATCH 4/5] mm: Reclaim small amounts of memory when an external fragmentation event occurs Mel Gorman
2018-11-27 9:23 ` Vlastimil Babka
2018-11-23 11:45 ` [PATCH 5/5] mm: Stall movable allocations until kswapd progresses during serious external fragmentation event Mel Gorman
2018-11-27 13:20 ` Vlastimil Babka
2018-11-27 17:51 ` Mel Gorman
2018-12-05 8:06 ` Mel Gorman
-- strict thread matches above, loose matches on Subject: below --
2018-11-07 18:38 [PATCH 0/5] Fragmentation avoidance improvements v2 Mel Gorman
2018-11-07 18:38 ` [PATCH 1/5] mm, page_alloc: Spread allocations across zones before introducing fragmentation Mel Gorman
2018-10-31 16:06 [PATCH 0/5] Fragmentation avoidance improvements Mel Gorman
2018-10-31 16:06 ` [PATCH 1/5] mm, page_alloc: Spread allocations across zones before introducing fragmentation 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=7a3b2706-8d8c-9233-d6fc-26ace52641e7@suse.cz \
--to=vbabka@suse.cz \
--cc=aarcange@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mgorman@techsingularity.net \
--cc=mhocko@kernel.org \
--cc=rientjes@google.com \
--cc=zi.yan@cs.rutgers.edu \
/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).