Re: Limiting program swap

William Lee Irwin III
2004-12-08T19:38:28Z

On Wed, Dec 08, 2004 at 02:07:36PM -0500, Bill Davidsen wrote:
> I have several machine of various memory sizes which suffer from really
> poor performance when doing backups. This appears to be because all the
> programs other than the backup quickly get swapped to make room for i/o
> buffers.
> Is there some standard portable way to prevent this, either by reserving
> some memory for programs which will not get swapped regardless of i/o
> pressure, or alternatively limiting the total memory used for i/o
> buffers, dcache, and similar things?
> I did a crude hack for 2.4.17, but if I'm missing some obvious trick I'd
> rather not do something which can't go in the mainline kernel. Anyone
> care to show me what I missed, or is this just a characteristic of Linux?

This appears at least superficially related to
/proc/sys/vm/vfs_cache_pressure in 2.6.x-mm (possibly also mainline)

-- wli