Re: [PATCH 2/3] mm: Send one IPI per CPU to TLB flush multiple pages that were recently unmapped

From: Rik van Riel
Date: Sun Apr 26 2015 - 22:49:20 EST

On 04/25/2015 01:45 PM, Mel Gorman wrote:
> An IPI is sent to flush remote TLBs when a page is unmapped that was
> recently accessed by other CPUs. There are many circumstances where this
> happens but the obvious one is kswapd reclaiming pages belonging to a
> running process as kswapd and the task are likely running on separate CPUs.

> It's still a noticeable improvement with vmstat showing interrupts went
> from roughly 500K per second to 45K per second.
> The patch will have no impact on workloads with no memory pressure or
> have relatively few mapped pages.
> Signed-off-by: Mel Gorman <mgorman@xxxxxxx>

Reviewed-by: Rik van Riel <riel@xxxxxxxxxx>

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