Re: [PATCH 0/10] Reduce system disruption due to kswapd V2

[Mel Gorman]

On Tue, Apr 09, 2013 at 05:27:18PM +0000, Christoph Lameter wrote:
> One additional measure that may be useful is to make kswapd prefer one
> specific processor on a socket. Two benefits arise from that:
> 
> 1. Better use of cpu caches and therefore higher speed, less
> serialization.
> 

Considering the volume of pages that kswapd can scan when it's active
I would expect that it trashes its cache anyway. The L1 cache would be
flushed after scanning struct pages for just a few MB of memory.

> 2. Reduction of the disturbances to one processor.
> 

I've never checked it but I would have expected kswapd to stay on the
same processor for significant periods of time. Have you experienced
problems where kswapd bounces around on CPUs within a node causing
workload disruption?

-- 
Mel Gorman
SUSE Labs
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