archive mirror
 help / color / mirror / Atom feed
From: "George Bonser" <>
To: "Rik van Riel" <>, <>
Cc: <>
Subject: RE: [PATCH] 2.4.6-pre2 page_launder() improvements
Date: Sun, 10 Jun 2001 01:38:01 -0700	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <Pine.LNX.4.33.0106100128100.4239-100000@duckman.distro.conectiva>

> This patch has given excellent results on my laptop and my
> workstation here and seems to improve kernel behaviour in tests
> quite a bit. I can play mp3's unbuffered during moderate write
> loads or moderately heavy IO ;)
> YMMV, please test it. If it works great for everybody I'd like
> to get this improvement merged into the next -pre kernel.

For the test I ran it through, it was about the same as 2.4.6-pre2 vanilla.

The test I did can be simulated easilly enough. Apache with keepalives off.
about 50 connections/second pulling a 10K file. Have half a gig of swap.
Told the machine on boot that it had 64MB of RAM. Prestarted 250 apache
children. Once everything settles down, I was about 10meg into swap and
everything is running smoothly. So far so good. Now I figured I would push
it a little more into swap so this being a production server, I can't really
tell the world to make more connections so I do the next best thing and turn
keepalives on with a timeout of 2 seconds figuring this would increase the
number of apache children alive and push me deeper into swap. Restarted
apache and within about 5 seconds the machine stopped responding to console
input. top would not update the screen but the machine would respond to

I took it out of the load balancer and regained control in seconds. The 15
minute load average showed somewhere over 150 with a bazillion apache
processes. Even top -q would not update when I put it back into the
balancer. The load average and number of processes started to increase until
I got to some point where it would just stop providing output. Again,
control returned within seconds after taking it out of the balancer. As far
as I could tell, I never at any time got more than 100MB into swap.

Your patch did seem to keep the machine alive a little longer but that is
subjective and I have no data to back that statement up. Vanilla 2.4.6-pre2
seemed to die off a little faster. Again, with both kernels, pings were
fine, just no interactive at all. I was logged in over the net with no
console so I could not see what was hogging the CPU bot it did not appear to
be a user process. That top -q would not update tells me it was likely in
the kernel because that runs as the highest priority user process. I just
could not get any CPU in user space.

  reply	other threads:[~2001-06-10  8:38 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2001-06-10  4:40 Rik van Riel
2001-06-10  8:38 ` George Bonser [this message]
2001-06-10  8:43   ` Rik van Riel
2001-06-10  8:52     ` George Bonser
2001-06-10  9:06     ` George Bonser
2001-06-10  9:08     ` George Bonser
2001-06-10 19:30     ` George Bonser
2001-06-11  3:03 ` Daniel Stone
2001-06-11 16:18   ` George Bonser
2001-06-13  4:42 ` Alok K. Dhir
2001-06-13 13:49   ` Rik van Riel
2001-06-13 18:46   ` Marcelo Tosatti

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:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \ \ \ \ \ \
    --subject='RE: [PATCH] 2.4.6-pre2 page_launder() improvements' \

* 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).