updatedb.mlocate reserves large amount of low memory

[Philip Hardegen]

DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=10.04
DISTRIB_CODENAME=lucid
DISTRIB_DESCRIPTION="Ubuntu 10.04.2 LTS"

2.6.32-34-generic-pae #77-Ubuntu SMP Tue Sep 13 21:16:18 UTC 2011 i686 GNU/Linux

32 GB RAM

mlocate:
  Installed: 0.22.2-1ubuntu1
  Candidate: 0.22.2-1ubuntu1
  Version table:
 *** 0.22.2-1ubuntu1 0
        500 http://archive.ubuntu.com/ubuntu/ lucid/main Packages
        100 /var/lib/dpkg/status

I noticed this after OOMKiller was being invoked. There were other causes attributed to this, but as I monitored low memory usage, I noticed a sharp drop in available low memory during cron.daily running. After some experimentation I found out that the culprit was updatedb.mlocate itself. None of the additional configuration by cron was causing the large low memory usage.

I can consistently have 180/458 MB free in low memory, and after running updatedb.mlocate it drops to 40/458 MB free.

I've read a bunch of reports about this causing IO and performance issues, but nothing about memory usage. Is it expected for it to reserve so much low memory?