From: Dave Hansen <dave.hansen@intel.com>
To: Johannes Weiner <hannes@cmpxchg.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Linux-MM <linux-mm@kvack.org>, Mel Gorman <mgorman@suse.de>,
Rik van Riel <riel@redhat.com>, Kevin Hilman <khilman@linaro.org>,
Andrea Arcangeli <aarcange@redhat.com>,
Paul Bolle <paul.bollee@gmail.com>,
Zlatko Calusic <zcalusic@bitsync.net>,
Andrew Morton <akpm@linux-foundation.org>,
Tim Chen <tim.c.chen@linux.intel.com>,
Andi Kleen <ak@linux.intel.com>
Subject: Re: NUMA? bisected performance regression 3.11->3.12
Date: Fri, 22 Nov 2013 08:57:06 -0800 [thread overview]
Message-ID: <528F8CE2.1000001@intel.com> (raw)
In-Reply-To: <20131122063845.GM3556@cmpxchg.org>
On 11/21/2013 10:38 PM, Johannes Weiner wrote:
> On Thu, Nov 21, 2013 at 10:18:44PM -0800, Dave Hansen wrote:
>> For what it's worth, I'm pretty convinced that the numbers folks put in
>> the SLIT tables are, at best, horribly inconsistent from system to
>> system. At worst, they're utter fabrications not linked at all to the
>> reality of the actual latencies.
>
> You mean the reported distances should probably be bigger on this
> particular machine?
Yeah, or smaller on the others that made us switch zone_reclaim_mode at
the place where we do.
> But even when correct, zone_reclaim_mode might not be the best
> predictor. Just because it's not worth yet to invest direct reclaim
> efforts to stay local does not mean that remote references are free.
>
> I'm currently running some tests with the below draft to see if this
> would still leave us with enough fairness. Does the patch restore
> performance even with zone_reclaim_mode disabled?
Yeah, that at least works for the one test where it's been causing the
most trouble.
--
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:[~2013-11-22 16:58 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-21 22:57 NUMA? bisected performance regression 3.11->3.12 Dave Hansen
2013-11-22 5:22 ` Johannes Weiner
2013-11-22 6:18 ` Dave Hansen
2013-11-22 6:38 ` Johannes Weiner
2013-11-22 16:57 ` Dave Hansen [this message]
2013-11-26 10:32 ` Mel Gorman
2013-12-06 17:43 ` Dave Hansen
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=528F8CE2.1000001@intel.com \
--to=dave.hansen@intel.com \
--cc=aarcange@redhat.com \
--cc=ak@linux.intel.com \
--cc=akpm@linux-foundation.org \
--cc=hannes@cmpxchg.org \
--cc=khilman@linaro.org \
--cc=linux-mm@kvack.org \
--cc=mgorman@suse.de \
--cc=paul.bollee@gmail.com \
--cc=riel@redhat.com \
--cc=tim.c.chen@linux.intel.com \
--cc=torvalds@linux-foundation.org \
--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 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).