[PATCH 14/22] mm, page_alloc: Simplify last cpupid reset

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From	Mel Gorman <mgorman@techsingularity.net>
Newsgroups	linux.kernel
Subject	[PATCH 14/22] mm, page_alloc: Simplify last cpupid reset
Date	Mon, 11 Apr 2016 10:20:03 +0200
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Show key headers only | View raw

The current reset unnecessarily clears flags and makes pointless calculations.

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
---
 include/linux/mm.h | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index ed6407d1b7b5..8f409818401c 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -837,10 +837,7 @@ extern int page_cpupid_xchg_last(struct page *page, int cpupid);
 
 static inline void page_cpupid_reset_last(struct page *page)
 {
-	int cpupid = (1 << LAST_CPUPID_SHIFT) - 1;
-
-	page->flags &= ~(LAST_CPUPID_MASK << LAST_CPUPID_PGSHIFT);
-	page->flags |= (cpupid & LAST_CPUPID_MASK) << LAST_CPUPID_PGSHIFT;
+	page->flags |= LAST_CPUPID_MASK << LAST_CPUPID_PGSHIFT;
 }
 #endif /* LAST_CPUPID_NOT_IN_PAGE_FLAGS */
 #else /* !CONFIG_NUMA_BALANCING */
-- 
2.6.4

Thread

[PATCH 00/21] Optimise page alloc/free fast paths Mel Gorman <mgorman@techsingularity.net> - 2016-04-11 10:20 +0200
  [PATCH 08/22] mm, page_alloc: Convert alloc_flags to unsigned Mel Gorman <mgorman@techsingularity.net> - 2016-04-11 10:20 +0200
  [PATCH 04/22] mm, page_alloc: Inline zone_statistics Mel Gorman <mgorman@techsingularity.net> - 2016-04-11 10:20 +0200
  [PATCH 21/22] cpuset: use static key better and convert to new API Mel Gorman <mgorman@techsingularity.net> - 2016-04-11 10:20 +0200
  [PATCH 11/22] mm, page_alloc: Remove unnecessary initialisation in get_page_from_freelist Mel Gorman <mgorman@techsingularity.net> - 2016-04-11 10:20 +0200
  [PATCH 14/22] mm, page_alloc: Simplify last cpupid reset Mel Gorman <mgorman@techsingularity.net> - 2016-04-11 10:20 +0200
  [PATCH 13/22] mm, page_alloc: Remove redundant check for empty zonelist Mel Gorman <mgorman@techsingularity.net> - 2016-04-11 10:20 +0200
  [PATCH 09/22] mm, page_alloc: Convert nr_fair_skipped to bool Mel Gorman <mgorman@techsingularity.net> - 2016-04-11 10:20 +0200
  [PATCH 15/22] mm, page_alloc: Move might_sleep_if check to the allocator slowpath Mel Gorman <mgorman@techsingularity.net> - 2016-04-11 10:20 +0200
  [PATCH 20/22] mm, page_alloc: Check multiple page fields with a single branch Mel Gorman <mgorman@techsingularity.net> - 2016-04-11 10:20 +0200
  [PATCH 12/22] mm, page_alloc: Remove unnecessary initialisation from __alloc_pages_nodemask() Mel Gorman <mgorman@techsingularity.net> - 2016-04-11 10:20 +0200
  [PATCH 19/22] mm, page_alloc: Avoid looking up the first zone in a zonelist twice Mel Gorman <mgorman@techsingularity.net> - 2016-04-11 10:20 +0200
  [PATCH 05/22] mm, page_alloc: Inline the fast path of the zonelist iterator Mel Gorman <mgorman@techsingularity.net> - 2016-04-11 10:20 +0200
  [PATCH 02/22] mm, page_alloc: Use new PageAnonHead helper in the free page fast path Mel Gorman <mgorman@techsingularity.net> - 2016-04-11 10:20 +0200
  [PATCH 16/22] mm, page_alloc: Move __GFP_HARDWALL modifications out of the fastpath Mel Gorman <mgorman@techsingularity.net> - 2016-04-11 10:20 +0200
  [PATCH 17/22] mm, page_alloc: Reduce cost of fair zone allocation policy retry Mel Gorman <mgorman@techsingularity.net> - 2016-04-11 10:20 +0200
  [PATCH 18/22] mm, page_alloc: Shortcut watermark checks for order-0 pages Mel Gorman <mgorman@techsingularity.net> - 2016-04-11 10:30 +0200
  Re: [PATCH 00/21] Optimise page alloc/free fast paths Mel Gorman <mgorman@techsingularity.net> - 2016-04-11 10:30 +0200
  [PATCH 06/22] mm, page_alloc: Use __dec_zone_state for order-0 page allocation Mel Gorman <mgorman@techsingularity.net> - 2016-04-11 10:30 +0200
  [PATCH 10/22] mm, page_alloc: Remove unnecessary local variable in get_page_from_freelist Mel Gorman <mgorman@techsingularity.net> - 2016-04-11 10:30 +0200
  [PATCH 07/22] mm, page_alloc: Avoid unnecessary zone lookups during pageblock operations Mel Gorman <mgorman@techsingularity.net> - 2016-04-11 10:30 +0200
  [PATCH 01/22] mm, page_alloc: Only check PageCompound for high-order pages Mel Gorman <mgorman@techsingularity.net> - 2016-04-11 10:40 +0200
  [PATCH 03/22] mm, page_alloc: Reduce branches in zone_statistics Mel Gorman <mgorman@techsingularity.net> - 2016-04-11 10:40 +0200

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