Messages in this thread | | | Date | Mon, 09 Apr 2012 16:53:25 +0900 | From | KAMEZAWA Hiroyuki <> | Subject | Re: [PATCH 2/2] huge-memory: Use fast mm counters for transparent huge pages |
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(2012/03/31 23:09), Andi Kleen wrote:
> From: Andi Kleen <ak@linux.intel.com> > > We found that the mm struct anon page counter cache line is much hotter > with transparent huge pages compared to small pages. > > Small pages use a special fast counter mechanism in task_struct, but huge pages > didn't. The huge pages are larger than the normal 64 entry threshold for the > fast counter, so it cannot be directly used. Use a new special counter for huge > pages to handle them efficiently. > > Any users just calculate the correct total. > > The only special case is transferring the large page count to small pages > when splitting. I put it somewhat arbitarily into the tricky split > sequence. Some review on this part is appreciated. > > [An alternative would be to not do that, but that could lead to > negative counters. These should still give the correct result] > > Contains a fix for a problem found by Andrea in review. > > Cc: aarcange@redhat.com > Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
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