mm: introduce single zone pcplists drain

The functions for draining per-cpu pages back to buddy allocators
currently always operate on all zones.  There are however several cases
where the drain is only needed in the context of a single zone, and
spilling other pcplists is a waste of time both due to the extra
spilling and later refilling.

This patch introduces new zone pointer parameter to drain_all_pages()
and changes the dummy parameter of drain_local_pages() to be also a zone
pointer.  When NULL is passed, the functions operate on all zones as
usual.  Passing a specific zone pointer reduces the work to the single
zone.

All callers are updated to pass the NULL pointer in this patch.
Conversion to single zone (where appropriate) is done in further
patches.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index 41b30fd4d041..07d2699cdb51 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -381,8 +381,8 @@ extern void free_kmem_pages(unsigned long addr, unsigned int order);
 
 void page_alloc_init(void);
 void drain_zone_pages(struct zone *zone, struct per_cpu_pages *pcp);
-void drain_all_pages(void);
-void drain_local_pages(void *dummy);
+void drain_all_pages(struct zone *zone);
+void drain_local_pages(struct zone *zone);
 
 /*
  * gfp_allowed_mask is set to GFP_BOOT_MASK during early boot to restrict what