memcg: change page_cgroup_zoneinfo signature
Instead of passing a whole struct page_cgroup to this function, let it
take only what it really needs from it: the struct mem_cgroup and the
page.
This has the advantage that reading pc->mem_cgroup is now done at the same
place where the ordering rules for this pointer are enforced and
explained.
It is also in preparation for removing the pc->page backpointer.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 5f7b0e1..2881c9e 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -364,11 +364,10 @@
}
static struct mem_cgroup_per_zone *
-page_cgroup_zoneinfo(struct page_cgroup *pc)
+page_cgroup_zoneinfo(struct mem_cgroup *mem, struct page *page)
{
- struct mem_cgroup *mem = pc->mem_cgroup;
- int nid = page_cgroup_nid(pc);
- int zid = page_cgroup_zid(pc);
+ int nid = page_to_nid(page);
+ int zid = page_zonenum(page);
return mem_cgroup_zoneinfo(mem, nid, zid);
}
@@ -800,7 +799,7 @@
* We don't check PCG_USED bit. It's cleared when the "page" is finally
* removed from global LRU.
*/
- mz = page_cgroup_zoneinfo(pc);
+ mz = page_cgroup_zoneinfo(pc->mem_cgroup, page);
/* huge page split is done under lru_lock. so, we have no races. */
MEM_CGROUP_ZSTAT(mz, lru) -= 1 << compound_order(page);
if (mem_cgroup_is_root(pc->mem_cgroup))
@@ -836,7 +835,7 @@
smp_rmb();
if (mem_cgroup_is_root(pc->mem_cgroup))
return;
- mz = page_cgroup_zoneinfo(pc);
+ mz = page_cgroup_zoneinfo(pc->mem_cgroup, page);
list_move_tail(&pc->lru, &mz->lists[lru]);
}
@@ -856,7 +855,7 @@
smp_rmb();
if (mem_cgroup_is_root(pc->mem_cgroup))
return;
- mz = page_cgroup_zoneinfo(pc);
+ mz = page_cgroup_zoneinfo(pc->mem_cgroup, page);
list_move(&pc->lru, &mz->lists[lru]);
}
@@ -873,7 +872,7 @@
return;
/* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
smp_rmb();
- mz = page_cgroup_zoneinfo(pc);
+ mz = page_cgroup_zoneinfo(pc->mem_cgroup, page);
/* huge page split is done under lru_lock. so, we have no races. */
MEM_CGROUP_ZSTAT(mz, lru) += 1 << compound_order(page);
SetPageCgroupAcctLRU(pc);
@@ -1043,7 +1042,7 @@
return NULL;
/* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
smp_rmb();
- mz = page_cgroup_zoneinfo(pc);
+ mz = page_cgroup_zoneinfo(pc->mem_cgroup, page);
if (!mz)
return NULL;
@@ -2192,7 +2191,7 @@
* We hold lru_lock, then, reduce counter directly.
*/
lru = page_lru(head);
- mz = page_cgroup_zoneinfo(head_pc);
+ mz = page_cgroup_zoneinfo(head_pc->mem_cgroup, head);
MEM_CGROUP_ZSTAT(mz, lru) -= 1;
}
tail_pc->flags = head_pc->flags & ~PCGF_NOCOPY_AT_SPLIT;