Re: Swappiness vs. mmap() and interactive response

Elladan
2009-04-30T04:56:34Z

On Wed, Apr 29, 2009 at 09:43:32PM -0700, Andrew Morton wrote:
> On Wed, 29 Apr 2009 21:14:39 -0700 Elladan <elladan@eskimo.com> wrote:
>
> > > Elladan, have you checked to see whether the Mapped: number in
> > > /proc/meminfo is decreasing?
> >
> > Yes, Mapped decreases while a large file copy is ongoing. It increases again
> > if I use the GUI.
>
> OK. If that's still happening to an appreciable extent after you've
> increased /proc/sys/vm/swappiness then I'd wager that we have a
> bug/regression in that area.
>
> Local variable `scan' in shrink_zone() is vulnerable to multiplicative
> overflows on large zones, but I doubt if you have enough memory to
> trigger that bug.

No, I only have 4GB.

This appears to happen with swappiness set to 0 or 60.

-Elladan