Re: Setting oom_adj on linux?

Stephen Frost <sfrost@snowman.net>

From: Stephen Frost <sfrost@snowman.net>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Alex Hunsaker <badalex@gmail.com>, Magnus Hagander <magnus@hagander.net>, Alvaro Herrera <alvherre@commandprompt.com>, Andrew Dunstan <andrew@dunslane.net>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2010-01-08T22:24:06Z
Lists: pgsql-hackers
* Tom Lane (tgl@sss.pgh.pa.us) wrote:
> Alex Hunsaker <badalex@gmail.com> writes:
> > Sure this was openssh? I just looked through the entire cvs history
> > for opensshp and found 0 references to 'oom' let alone 'oom_adj'.
> > Maybe something distro specific?
> 
> FWIW, I see no evidence that sshd on Fedora does anything to change its
> oom score --- the oom_adj file reads as zero for both the parent daemon
> and its children.  Kinda scary to realize the OOM killer could easily
> lock me out of boxes I run headless.

There were a few issues, as it turns out, the particularly annoying one
was in the init script which caused upgrades to fail due to sshd not
being restarted, bug report here:

http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=473573

The other issue was with a Debian-specific patch which was applied to
OpenSSH which basically just created noise in the log file, bug report
here:

http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=487325

In the end, the problem was with errors being returned from attempts to
modify oom_adj.  As long as we can just ignore those hopefully there
won't be any issues.

	Thanks,

		Stephen