Re: [PATCH] mm: hugetlb: flush dcache before returning zeroed hugepage to userspace

[Will Deacon]

On Thu, Aug 16, 2012 at 06:25:27PM +0100, Michal Hocko wrote:
> On Thu 16-08-12 17:09:54, Will Deacon wrote:
> > On Wed, Aug 08, 2012 at 05:26:07PM +0100, Michal Hocko wrote:
> > > I guess the cleanest way is to hook into dequeue_huge_page_node and add
> > > something like arch_clear_hugepage_flags.
> > 
> > I hooked into enqueue_huge_page instead, but how about something like this?:
> 
> Do you have any specific reason for that? enqueue_huge_page is called on
> pages which potentially never get used so isn't that wasting a bit?
> Not that it would be wrong I was just thinking why shouldn't we do it
> when the page is actualy going to be used for sure.

I just did it that way to match the flag clearing for normal pages. I can
move it into dequeue if you think it's worthwhile but in the worst case it
just adds a clear_bit call, so I doubt it's measurable.

Will
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