linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Stephan von Krawczynski <skraw@ithnet.com>
To: Gergely Madarasz <gorgo@thunderchild.debian.net>
Cc: linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: vm problems
Date: Wed, 29 Aug 2001 14:26:39 +0200	[thread overview]
Message-ID: <20010829142639.27385bcf.skraw@ithnet.com> (raw)
In-Reply-To: <20010829131419.Z6202@thunderchild.ikk.sztaki.hu>
In-Reply-To: <20010829131419.Z6202@thunderchild.ikk.sztaki.hu>

On Wed, 29 Aug 2001 13:14:19 +0200
Gergely Madarasz <gorgo@thunderchild.debian.net> wrote:

> Hello,
> 
> I get hundreds of this error message:
> 
> __alloc_pages: 0-order allocation failed.
> 
> The machine is an IBM x250 with 4G ram, the kernel is vanilla 2.4.9 and
> 2.4.9-ac3, no swap, running bonnie++. When the memory fills up with cache,
> I start receiving the error message. 
> 
>              total       used       free     shared    buffers     cached
> Mem:       3863628    3854532       9096          0       5160    3734832
> -/+ buffers/cache:     114540    3749088
> Swap:            0          0          0

Unfortunately I found out this is "normal" behaviour, not only under 2.4.9 but also 2.4.8 and 2.4.7. You could use just about any test that does filesystem load with more data moved than you have physical mem. It basically means that you can easily break the vm management by forcing it in a state where "cleanup" has to be done to find free pages (e.g. page_launder). If you have enough spare time you can try to make page_launder run not only through 1/64 of the list but all through and find out in the end, that it cannot find free pages not matter how often it is run. This looks like a self-produced deadlock situation. On the one hand the basic strategy seems to use as much resources (mem) as possible to gain speed, on the other hand there is no way out, if resources get very low, and this basic strategy fails (which you can see because performance drops down below the cellar).
Try 2.4.10-pre2, possibly you find out, that it doesn't fail that often, but performance stays low.

Regards, Stephan



      parent reply	other threads:[~2001-08-29 12:32 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2001-08-29 11:14 vm problems Gergely Madarasz
2001-08-29 11:47 ` Gergely Madarasz
2001-08-29 22:02   ` Daniel Phillips
2001-08-29 12:26 ` Stephan von Krawczynski [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=20010829142639.27385bcf.skraw@ithnet.com \
    --to=skraw@ithnet.com \
    --cc=gorgo@thunderchild.debian.net \
    --cc=linux-kernel@vger.kernel.org \
    /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).