LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Linus Torvalds <torvalds@linux-foundation.org>
To: Dave Chinner <david@fromorbit.com>
Cc: Mel Gorman <mgorman@suse.de>,
	Andrew Morton <akpm@linux-foundation.org>,
	Ingo Molnar <mingo@kernel.org>, Matt B <jackdachef@gmail.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	linux-mm <linux-mm@kvack.org>,
	xfs@oss.sgi.com
Subject: Re: [regression v4.0-rc1] mm: IPIs from TLB flushes causing significant performance degradation.
Date: Mon, 2 Mar 2015 22:56:14 -0800	[thread overview]
Message-ID: <CA+55aFyczb5asoTwhzaJr1JdRi1epg1A6cFJgnzMMZj6U0gFWA@mail.gmail.com> (raw)
In-Reply-To: <20150303052004.GM18360@dastard>

On Mon, Mar 2, 2015 at 9:20 PM, Dave Chinner <david@fromorbit.com> wrote:
>>
>> But are those migrate-page calls really common enough to make these
>> things happen often enough on the same pages for this all to matter?
>
> It's looking like that's a possibility.

Hmm. Looking closer, commit 10c1045f28e8 already should have
re-introduced the "pte was already NUMA" case.

So that's not it either, afaik. Plus your numbers seem to say that
it's really "migrate_pages()" that is done more. So it feels like the
numa balancing isn't working right.

But I'm not seeing what would cause that in that commit. It really all
looks the same to me. The few special-cases it drops get re-introduced
later (although in a different form).

Mel, do you see what I'm missing?

                     Linus

  reply	other threads:[~2015-03-03  6:56 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-03-02  1:04 Dave Chinner
2015-03-02 19:47 ` Linus Torvalds
2015-03-03  1:47   ` Dave Chinner
2015-03-03  2:22     ` Linus Torvalds
2015-03-03  2:37       ` Linus Torvalds
2015-03-03  5:20         ` Dave Chinner
2015-03-03  6:56           ` Linus Torvalds [this message]
2015-03-03 11:34             ` Dave Chinner
2015-03-03 13:43               ` Mel Gorman
2015-03-03 21:33                 ` Dave Chinner
2015-03-04 20:00                   ` Mel Gorman
2015-03-04 23:00                     ` Dave Chinner
2015-03-04 23:35                       ` Ingo Molnar
2015-03-04 23:51                         ` Dave Chinner
2015-03-02 19:17 Matt
2015-03-02 19:25 ` Dave Hansen
2015-03-02 19:45   ` Matt

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=CA+55aFyczb5asoTwhzaJr1JdRi1epg1A6cFJgnzMMZj6U0gFWA@mail.gmail.com \
    --to=torvalds@linux-foundation.org \
    --cc=akpm@linux-foundation.org \
    --cc=david@fromorbit.com \
    --cc=jackdachef@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mgorman@suse.de \
    --cc=mingo@kernel.org \
    --cc=xfs@oss.sgi.com \
    --subject='Re: [regression v4.0-rc1] mm: IPIs from TLB flushes causing significant performance degradation.' \
    /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

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).