Re: Memory management in Kernel 2.4.x

[Andrea Arcangeli]

On Mon, May 27, 2002 at 03:45:55PM +0200, Peter Wächtler wrote:
> Andreas Hartmann wrote:
> >Zwane Mwaikambo wrote:
> >
> >
> >>On Mon, 27 May 2002, Andreas Hartmann wrote:
> >>
> >>
> >>>rsync allocates all of the memory the machine has (256 MB RAM, 128 MB
> >>>swap). When this occures, processes get killed like described in the
> >>>posting before. The machine doesn't respond as long as the rsync -
> >>>process isn't killed, because it fetches all the memory which gets free
> >>>after a process has been killed.
> >>>
> >>And the rsync process never gets singled out? nice!
> >>
> >
> >Until it's killed by the kernel (if overcommitment isn't deactivated). If 
> >overcommitment is deactivated, the services of the machine are dead 
> >forever. There will be nothing, which kills such a process. Or am I wrong?
> >
> 
> There is still the oom killer (Out Of Memory).
> But it doesn't trigger and the machine pages "forever".
> Usually kswapd eats the CPU then, discarding and reloading pages,
> searching lists for pages to evict and so on.

can you reproduce with 2.4.19pre9aa2? I expect at least the deadlock
(if it's a deadlock and not a livelock) should go away.

Also I read in another email that somebody grown the per-socket buffer
to hundred mbytes, if you do that on a 32bit arch with highmem you'll
run into troubles, too much ZONE_NORMAL ram will be constantly pinned
for the tcp pipeline and the machine can enter livelocks.

Andrea