mm: microoptimize zonelist operations
next_zones_zonelist() returns a zoneref pointer, as well as a zone pointer
via extra parameter. Since the latter can be trivially obtained by
dereferencing the former, the overhead of the extra parameter is
unjustified.
This patch thus removes the zone parameter from next_zones_zonelist().
Both callers happen to be in the same header file, so it's simple to add
the zoneref dereference inline. We save some bytes of code size.
add/remove: 0/0 grow/shrink: 0/3 up/down: 0/-105 (-105)
function old new delta
nr_free_zone_pages 129 115 -14
__alloc_pages_nodemask 2300 2285 -15
get_page_from_freelist 2652 2576 -76
add/remove: 0/0 grow/shrink: 1/0 up/down: 10/0 (10)
function old new delta
try_to_compact_pages 569 579 +10
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index b418297..f279d9c 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -970,7 +970,6 @@
* @z - The cursor used as a starting point for the search
* @highest_zoneidx - The zone index of the highest zone to return
* @nodes - An optional nodemask to filter the zonelist with
- * @zone - The first suitable zone found is returned via this parameter
*
* This function returns the next zone at or below a given zone index that is
* within the allowed nodemask using a cursor as the starting point for the
@@ -980,8 +979,7 @@
*/
struct zoneref *next_zones_zonelist(struct zoneref *z,
enum zone_type highest_zoneidx,
- nodemask_t *nodes,
- struct zone **zone);
+ nodemask_t *nodes);
/**
* first_zones_zonelist - Returns the first zone at or below highest_zoneidx within the allowed nodemask in a zonelist
@@ -1000,8 +998,10 @@
nodemask_t *nodes,
struct zone **zone)
{
- return next_zones_zonelist(zonelist->_zonerefs, highest_zoneidx, nodes,
- zone);
+ struct zoneref *z = next_zones_zonelist(zonelist->_zonerefs,
+ highest_zoneidx, nodes);
+ *zone = zonelist_zone(z);
+ return z;
}
/**
@@ -1018,7 +1018,8 @@
#define for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, nodemask) \
for (z = first_zones_zonelist(zlist, highidx, nodemask, &zone); \
zone; \
- z = next_zones_zonelist(++z, highidx, nodemask, &zone)) \
+ z = next_zones_zonelist(++z, highidx, nodemask), \
+ zone = zonelist_zone(z)) \
/**
* for_each_zone_zonelist - helper macro to iterate over valid zones in a zonelist at or below a given zone index
diff --git a/mm/mmzone.c b/mm/mmzone.c
index bf34fb8..7d87ebb 100644
--- a/mm/mmzone.c
+++ b/mm/mmzone.c
@@ -54,8 +54,7 @@
/* Returns the next zone at or below highest_zoneidx in a zonelist */
struct zoneref *next_zones_zonelist(struct zoneref *z,
enum zone_type highest_zoneidx,
- nodemask_t *nodes,
- struct zone **zone)
+ nodemask_t *nodes)
{
/*
* Find the next suitable zone to use for the allocation.
@@ -69,7 +68,6 @@
(z->zone && !zref_in_nodemask(z, nodes)))
z++;
- *zone = zonelist_zone(z);
return z;
}
