Messages in this thread | | | Date | Fri, 28 Jun 2013 11:36:25 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH 7/8] sched: Split accounting of NUMA hinting faults that pass two-stage filter |
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On Fri, Jun 28, 2013 at 12:30:27PM +0530, Srikar Dronamraju wrote: > * Mel Gorman <mgorman@suse.de> [2013-06-26 15:38:06]: > > > Ideally it would be possible to distinguish between NUMA hinting faults > > that are private to a task and those that are shared. This would require > > that the last task that accessed a page for a hinting fault would be > > recorded which would increase the size of struct page. Instead this patch > > approximates private pages by assuming that faults that pass the two-stage > > filter are private pages and all others are shared. The preferred NUMA > > node is then selected based on where the maximum number of approximately > > private faults were measured. > > Should we consider only private faults for preferred node?
I don't think so; its optimal for the task to be nearest most of its pages; irrespective of whether they be private or shared.
> I would think if tasks have shared pages then moving all tasks that share > the same pages to a node where the share pages are around would be > preferred. No?
Well no; not if there's only 5 shared pages but 1024 private pages.
> If yes, how does the preferred node logic help to achieve > the above?
There's no packing logic yet...
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