lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID:  <slrngjt7b4.d62.davidf+nntp@dog.thdo.woaf.net>
Date:	Tue, 9 Dec 2008 16:31:32 +0000 (UTC)
From:	David Flynn <davidf+nntp@...f.net>
To:	linux-kernel@...r.kernel.org
Subject:  Re: 2.6.26.3 kernel - progressive slowdown over NFS

On 2008-09-10, Priyank Patel <pkpatel.lists@...il.com> wrote:
> We have a simple python program which keeps running a C loop to lstat
> NFS mounted directories.  We are seeing some weird behavior w.r.t. the
> run-time of this program on 2.6.26.3 kernel vs 2.6.24 kernel.
>
> The run-time of the following code increases over time on the 2.6.26.3
> kernel, whereas remains flat (as expected) on the 2.6.24 kernel.

I'm seeing a similar effect, and ran a benchmark pre and post reboot:

 $ strace -T /usr/sbin/bonnie++ -d . -s 0 -f -n 1 >/tmp/bonnie-r44237-netslow 2>&1
 ...reboot...
 $ strace -T /usr/sbin/bonnie++ -d . -s 0 -f -n 1 >/tmp/bonnie-r44237-netfast 2>&1

Graphs of the operations are avaliable:
  http://davidf.woaf.net/nfsfail-2.6.26/

In particular http://davidf.woaf.net/nfsfail-2.6.26/r44237-stat.pdf

r44237-* was a machine with a 28 day uptime and
r44088-* is an identical machine with 14 day uptime.

The graphs show times as recorded by strace for each syscall (points), a
cumulative frequency plot is also drawn on the same graph (lines).
yellow-orange points/lines are before the reboot, purple afterwards.

The machines are part of a cluster with a r/o nfsroot and common debian
stock kernel:
 Linux r44088 2.6.26-1-amd64 #1 SMP Sat Aug 2 11:15:08 GMT 2008 x86_64 GNU/Linux

Other nfs filesystems are also mounted; all nfs mounts are nfsv3 over udp.

Has this issue been identified or resolved in 2.6.27?

Extra logs can be provided if required.

..david

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ