Date: Mon, 13 Feb 2006 13:16:00 -0800 (PST)
From: Christoph Lameter <clameter@xxxxxxxxxxxx>
To: David Lang <dlang@xxxxxxxxxxxxxxxxxx>
Cc: Con Kolivas <kernel@xxxxxxxxxxx>,
linux kernel mailing list <linux-kernel@xxxxxxxxxxxxxxx>,
Andrew Morton <akpm@xxxxxxxx>, ck list <ck@xxxxxxxxxxxxxxx>
Subject: Re: [PATCH] mm: Implement Swap Prefetching v25
On Mon, 13 Feb 2006, David Lang wrote:
On Mon, 13 Feb 2006, Christoph Lameter wrote:spare ram when swapping??? We are already under memory pressure. Why makewhen a program exits it's memory is now free, rather then just waiting until
it worse by getting rid of the few bits of available memory? If a system
swaps then we are per definition in the bad performance range. Add more
memory.
something uses this memory up normally, this patch attempts to fill that
memory with things that are expected to be useful (things that were swapped
out)
Then trigger this action when a program exits and when you know there was
enough freed up to justify such an action. However, this is still a
heuristic. No one knows if the pages read from swap will be of any use at
all. For all I know a process may want to allocate some memory and fail
because the memory was needlessly spend to read in pages that no one
needs.