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
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next prev parent reply other threads:[~2015-03-03 6:56 UTC|newest]
Thread overview: 14+ 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
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