Re: [PATCH 1/2] mm: Disable zone_reclaim_mode by default

[Johannes Weiner]

On Mon, Apr 07, 2014 at 11:34:27PM +0100, Mel Gorman wrote:
> zone_reclaim_mode causes processes to prefer reclaiming memory from local
> node instead of spilling over to other nodes. This made sense initially when
> NUMA machines were almost exclusively HPC and the workload was partitioned
> into nodes. The NUMA penalties were sufficiently high to justify reclaiming
> the memory. On current machines and workloads it is often the case that
> zone_reclaim_mode destroys performance but not all users know how to detect
> this. Favour the common case and disable it by default. Users that are
> sophisticated enough to know they need zone_reclaim_mode will detect it.
> 
> Signed-off-by: Mel Gorman <mgorman@xxxxxxx>

Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>
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