The patch titled
Subject: mm, page_alloc: don't check cpuset allowed twice in fast-path
has been removed from the -mm tree. Its filename was
mm-page_alloc-dont-check-cpuset-allowed-twice-in-fast-path.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Vlastimil Babka <vbabka@xxxxxxx>
Subject: mm, page_alloc: don't check cpuset allowed twice in fast-path
Since 682a3385e773 ("mm, page_alloc: inline the fast path of the zonelist
iterator") we replace a NULL nodemask with cpuset_current_mems_allowed in
the fast path, so that get_page_from_freelist() filters nodes allowed by
the cpuset via for_next_zone_zonelist_nodemask(). In that case it's
pointless to additionaly check __cpuset_zone_allowed() in each iteration,
which we can avoid by not adding ALLOC_CPUSET to alloc_flags in that
scenario.
This saves some cycles in the allocator fast path on systems with one or
more non-root cpuset configured. In the slow path, ALLOC_CPUSET is reset
according to __alloc_pages_slowpath(). Without configured cpusets, this
code is disabled by a static key.
Link: http://lkml.kernel.org/r/20170124150511.5710-2-vbabka@xxxxxxx
Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx>
Reviewed-by: Anshuman Khandual <khandual@xxxxxxxxxxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Cc: Anshuman Khandual <khandual@xxxxxxxxxxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/page_alloc.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff -puN mm/page_alloc.c~mm-page_alloc-dont-check-cpuset-allowed-twice-in-fast-path mm/page_alloc.c
--- a/mm/page_alloc.c~mm-page_alloc-dont-check-cpuset-allowed-twice-in-fast-path
+++ a/mm/page_alloc.c
@@ -3903,9 +3903,10 @@ static inline bool prepare_alloc_pages(g
if (cpusets_enabled()) {
*alloc_mask |= __GFP_HARDWALL;
- *alloc_flags |= ALLOC_CPUSET;
if (!ac->nodemask)
ac->nodemask = &cpuset_current_mems_allowed;
+ else
+ *alloc_flags |= ALLOC_CPUSET;
}
lockdep_trace_alloc(gfp_mask);
_
Patches currently in -mm which might be from vbabka@xxxxxxx are
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