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| author | Mel Gorman | 2016-05-20 02:13:30 +0200 |
|---|---|---|
| committer | Linus Torvalds | 2016-05-20 04:12:14 +0200 |
| commit | 682a3385e7734fa3abbd504cbeb5fe91793f1827 (patch) | |
| tree | 1371b57acda5bb81e15bed95d82d155dae00bf65 /include/linux/mmzone.h | |
| parent | mm, page_alloc: inline zone_statistics (diff) | |
| download | kernel-qcow2-linux-682a3385e7734fa3abbd504cbeb5fe91793f1827.tar.gz kernel-qcow2-linux-682a3385e7734fa3abbd504cbeb5fe91793f1827.tar.xz kernel-qcow2-linux-682a3385e7734fa3abbd504cbeb5fe91793f1827.zip | |
mm, page_alloc: inline the fast path of the zonelist iterator
The page allocator iterates through a zonelist for zones that match the
addressing limitations and nodemask of the caller but many allocations
will not be restricted. Despite this, there is always functional call
overhead which builds up.
This patch inlines the optimistic basic case and only calls the iterator
function for the complex case. A hindrance was the fact that
cpuset_current_mems_allowed is used in the fastpath as the allowed
nodemask even though all nodes are allowed on most systems. The patch
handles this by only considering cpuset_current_mems_allowed if a cpuset
exists. As well as being faster in the fast-path, this removes some
junk in the slowpath.
The performance difference on a page allocator microbenchmark is;
4.6.0-rc2 4.6.0-rc2
statinline-v1r20 optiter-v1r20
Min alloc-odr0-1 412.00 ( 0.00%) 382.00 ( 7.28%)
Min alloc-odr0-2 301.00 ( 0.00%) 282.00 ( 6.31%)
Min alloc-odr0-4 247.00 ( 0.00%) 233.00 ( 5.67%)
Min alloc-odr0-8 215.00 ( 0.00%) 203.00 ( 5.58%)
Min alloc-odr0-16 199.00 ( 0.00%) 188.00 ( 5.53%)
Min alloc-odr0-32 191.00 ( 0.00%) 182.00 ( 4.71%)
Min alloc-odr0-64 187.00 ( 0.00%) 177.00 ( 5.35%)
Min alloc-odr0-128 185.00 ( 0.00%) 175.00 ( 5.41%)
Min alloc-odr0-256 193.00 ( 0.00%) 184.00 ( 4.66%)
Min alloc-odr0-512 207.00 ( 0.00%) 197.00 ( 4.83%)
Min alloc-odr0-1024 213.00 ( 0.00%) 203.00 ( 4.69%)
Min alloc-odr0-2048 220.00 ( 0.00%) 209.00 ( 5.00%)
Min alloc-odr0-4096 226.00 ( 0.00%) 214.00 ( 5.31%)
Min alloc-odr0-8192 229.00 ( 0.00%) 218.00 ( 4.80%)
Min alloc-odr0-16384 229.00 ( 0.00%) 219.00 ( 4.37%)
perf indicated that next_zones_zonelist disappeared in the profile and
__next_zones_zonelist did not appear. This is expected as the
micro-benchmark would hit the inlined fast-path every time.
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/mmzone.h')
| -rw-r--r-- | include/linux/mmzone.h | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 150c6049f961..cfcd7723edb6 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -919,6 +919,10 @@ static inline int zonelist_node_idx(struct zoneref *zoneref) #endif /* CONFIG_NUMA */ } +struct zoneref *__next_zones_zonelist(struct zoneref *z, + enum zone_type highest_zoneidx, + nodemask_t *nodes); + /** * next_zones_zonelist - Returns the next zone at or below highest_zoneidx within the allowed nodemask using a cursor within a zonelist as a starting point * @z - The cursor used as a starting point for the search @@ -931,9 +935,14 @@ static inline int zonelist_node_idx(struct zoneref *zoneref) * being examined. It should be advanced by one before calling * next_zones_zonelist again. */ -struct zoneref *next_zones_zonelist(struct zoneref *z, +static __always_inline struct zoneref *next_zones_zonelist(struct zoneref *z, enum zone_type highest_zoneidx, - nodemask_t *nodes); + nodemask_t *nodes) +{ + if (likely(!nodes && zonelist_zone_idx(z) <= highest_zoneidx)) + return z; + return __next_zones_zonelist(z, highest_zoneidx, nodes); +} /** * first_zones_zonelist - Returns the first zone at or below highest_zoneidx within the allowed nodemask in a zonelist |