Re: [PATCH 02/10] mm: system wide ALLOC_NO_WATERMARK

Daniel Phillips
2007-08-06T18:21:50Z

On Monday 06 August 2007 11:11, Christoph Lameter wrote:
> On Mon, 6 Aug 2007, Peter Zijlstra wrote:
> > Change ALLOC_NO_WATERMARK page allocation such that dipping into
> > the reserves becomes a system wide event.
>
> Shudder. That can just be a desaster for NUMA. Both performance wise
> and logic wise. One cpuset being low on memory should not affect
> applications in other cpusets.

Currently your system likely would have died here, so ending up with a
reserve page temporarily on the wrong node is already an improvement.

I agree that the reserve pool should be per-node in the end, but I do
not think that serves the interest of simplifying the initial patch
set. How about a numa performance patch that adds onto the end of
Peter's series?

Regards,

Daniel