Re: [RFC PATCH 0/6] TLB flush multiple pages with a single IPI v3

From: Mel Gorman
Date: Fri Apr 24 2015 - 11:17:48 EST


On Fri, Apr 24, 2015 at 04:46:22PM +0200, Vlastimil Babka wrote:
> On 04/21/2015 12:41 PM, Mel Gorman wrote:
> >Changelog since V2
> >o Ensure TLBs are flushed before pages are freed (mel)
>
> I admit not reading all the patches thoroughly, but doesn't this
> change of ordering mean that you no longer need the architectural
> guarantee discussed in patch 2?

No. If we unmap a page to write it to disk then we cannot allow a CPU to
write to the physical page being written through a cached entry.

--
Mel Gorman
SUSE Labs
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