mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Rik van Riel <riel@redhat.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: "Luck, Tony" <tony.luck@intel.com>,
	Linux kernel Mailing List <linux-kernel@vger.kernel.org>,
	shak <dshaks@redhat.com>
Subject: Re: [PATCH -mm] change anon_vma linking to fix multi-process server scalability issue
Date: Thu, 11 Feb 2010 16:49:35 -0500	[thread overview]
Message-ID: <4B747B6F.1090209@redhat.com> (raw)
In-Reply-To: <20100211130422.f262be71.akpm@linux-foundation.org>

On 02/11/2010 04:04 PM, Andrew Morton wrote:
> On Thu, 28 Jan 2010 00:20:00 -0500
> Rik van Riel<riel@redhat.com>  wrote:
>
>> The old anon_vma code can lead to scalability issues with heavily
>> forking workloads.  Specifically, each anon_vma will be shared
>> between the parent process and all its child processes.

Some test results:

Without the anon_vma changes, when AIM7 hits around 9.7k
users (on a test box with 16GB RAM and not quite enough IO),
the system ends up running >99% in system time, with every
CPU on the same anon_vma lock in the pageout code.

With these changes, AIM7 hits the cross-over point around
29.7k users.  This happens with ~99% IO wait time, there
never seems to be any spike in system time.  The anon_vma
lock contention appears to be resolved.

-- 
All rights reversed.

      parent reply	other threads:[~2010-02-11 21:49 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-01-28  5:20 Rik van Riel
2010-01-28  6:43 ` [PATCH -mm] rmap: remove obsolete check from __page_check_anon_rmap Rik van Riel
2010-02-01 15:26   ` Minchan Kim
2010-01-28  6:43 ` [PATCH -mm] rmap: move exclusively owned pages to own anon_vma in do_wp_page Rik van Riel
2010-02-01 15:25   ` Minchan Kim
2010-02-01 16:33     ` Rik van Riel
2010-01-28 16:37 ` [PATCH -mm] change anon_vma linking to fix multi-process server scalability issue Minchan Kim
2010-01-28 17:24   ` Rik van Riel
2010-01-29  0:55     ` Minchan Kim
2010-01-29  1:18       ` Rik van Riel
2010-01-29 23:14 ` Andrew Morton
2010-01-29 23:57   ` Rik van Riel
2010-01-30  0:22   ` [PATCH -mm] further cleanups to " Rik van Riel
2010-01-30  0:34   ` [PATCH -mm] remove VM_LOCK_RMAP code Rik van Riel
2010-02-01  6:15     ` Nick Piggin
2010-02-01 15:55       ` Rik van Riel
2010-02-02  6:44         ` Nick Piggin
     [not found] ` <20100211130422.f262be71.akpm@linux-foundation.org>
2010-02-11 21:49   ` Rik van Riel [this message]

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=4B747B6F.1090209@redhat.com \
    --to=riel@redhat.com \
    --cc=akpm@linux-foundation.org \
    --cc=dshaks@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=tony.luck@intel.com \
    /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

Powered by JetHome