KernelTrap: Automatically-Shrinking Caches

“Andreas Gruenbacher posted a patch to lkml that would allow for
‘dynamically sized caches that shrink under pressure’ (caches that
shrink when available physical memory is low). This feature seems a
bit controversial, since the traditional approach has always been
to cache as much as possible, and to swapout under pressure. The
rationale is that you want to have as much cache in RAM, to reduce
disk access.

“Members of the other party, however, argue that having too much
cache on disk is counterproductive; and that it is better to free
unused cache under pressure.

“It looks like this patch will make it in, though. Quoth Linus:
‘Yah, it’s a guess. We can test it…'”

Complete
Story