Messages in this thread | | | Date | Thu, 09 Jan 2014 14:49:35 -0500 | From | Rik van Riel <> | Subject | Re: [PATCH 3/5] x86: mm: Eliminate redundant page table walk during TLB range flushing |
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On 01/09/2014 09:34 AM, Mel Gorman wrote: > When choosing between doing an address space or ranged flush, the x86 > implementation of flush_tlb_mm_range takes into account whether there are > any large pages in the range. A per-page flush typically requires fewer > entries than would covered by a single large page and the check is redundant. > > There is one potential exception. THP migration flushes single THP entries > and it conceivably would benefit from flushing a single entry instead > of the mm. However, this flush is after a THP allocation, copy and page > table update potentially with any other threads serialised behind it. In > comparison to that, the flush is noise. It makes more sense to optimise > balancing to require fewer flushes than to optimise the flush itself. > > This patch deletes the redundant huge page check. > > Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
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