Re: buffer leakage in kernel?

[Andreas Dilger]

On Jan 24, 2003  13:49 +0100, Roman Dementiev wrote:
> I've met with following problem (kernel 2.4.20-pre4 ):
> I write and read sequentially from/to 8 files each of 64 Gbytes (not a
> mistake, 64 Gbyte),
> each on different disk. The files are opened with flag O_DIRECT. I have
> 1 Gbyte RAM, no swap.
> While this scanning is running, number of "buffers" reported by ''free"
> and in /proc/meminfo
> is continuously increasing up to ~ 500 MB !! When the program exits
> normally or I break it, number
> of "buffers" does not decrease and even increases if I do operations on
> other files.
> 
> This is not nice at all when I have another applications running
> with memory consumption > 500 MB: when my "scanner" approaches 50G
> border on each disk, I've got numerous  "Out of memory" murders :(.
> Even 'ssh' to this machine is killed :(

There was a bug in vanilla 2.4.18 related to O_DIRECT that is fixed in the
RH kernel, but I don't know when/if it was merged into the main kernel.
As always, testing with the most recent kernel (2.4.21-pre3 currently)
will tell you whether that bug has been fixed already or not.

Cheers, Andreas
--
Andreas Dilger
http://sourceforge.net/projects/ext2resize/
http://www-mddsp.enel.ucalgary.ca/People/adilger/