page allocator: do not call get_pageblock_migratetype() more than necessary
get_pageblock_migratetype() is potentially called twice for every page free. Once, when being freed to the pcp lists and once when being freed back to buddy. When freeing from the pcp lists, it is known what the pageblock type was at the time of free so use it rather than rechecking. In low memory situations under memory pressure, this might skew anti-fragmentation slightly but the interference is minimal and decisions that are fragmenting memory are being made anyway. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Reviewed-by: Christoph Lameter <cl@linux-foundation.org> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Dave Hansen <dave@linux.vnet.ibm.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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