From 38c5d72f3ebe5ddd57d2f08dc035070fc6c9a287 Mon Sep 17 00:00:00 2001 From: KAMEZAWA Hiroyuki Date: Thu, 12 Jan 2012 17:19:01 -0800 Subject: memcg: simplify LRU handling by new rule Now, at LRU handling, memory cgroup needs to do complicated works to see valid pc->mem_cgroup, which may be overwritten. This patch is for relaxing the protocol. This patch guarantees - when pc->mem_cgroup is overwritten, page must not be on LRU. By this, LRU routine can believe pc->mem_cgroup and don't need to check bits on pc->flags. This new rule may adds small overheads to swapin. But in most case, lru handling gets faster. After this patch, PCG_ACCT_LRU bit is obsolete and removed. [akpm@linux-foundation.org: remove unneeded VM_BUG_ON(), restore hannes's christmas tree] [akpm@linux-foundation.org: clean up code comment] [hughd@google.com: fix NULL mem_cgroup_try_charge] Signed-off-by: KAMEZAWA Hiroyuki Cc: Miklos Szeredi Acked-by: Michal Hocko Acked-by: Johannes Weiner Cc: Ying Han Signed-off-by: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/page_cgroup.h | 8 -------- 1 file changed, 8 deletions(-) (limited to 'include') diff --git a/include/linux/page_cgroup.h b/include/linux/page_cgroup.h index 1153095ee457..a2d11771c84b 100644 --- a/include/linux/page_cgroup.h +++ b/include/linux/page_cgroup.h @@ -10,8 +10,6 @@ enum { /* flags for mem_cgroup and file and I/O status */ PCG_MOVE_LOCK, /* For race between move_account v.s. following bits */ PCG_FILE_MAPPED, /* page is accounted as "mapped" */ - /* No lock in page_cgroup */ - PCG_ACCT_LRU, /* page has been accounted for (under lru_lock) */ __NR_PCG_FLAGS, }; @@ -75,12 +73,6 @@ TESTPCGFLAG(Used, USED) CLEARPCGFLAG(Used, USED) SETPCGFLAG(Used, USED) -SETPCGFLAG(AcctLRU, ACCT_LRU) -CLEARPCGFLAG(AcctLRU, ACCT_LRU) -TESTPCGFLAG(AcctLRU, ACCT_LRU) -TESTCLEARPCGFLAG(AcctLRU, ACCT_LRU) - - SETPCGFLAG(FileMapped, FILE_MAPPED) CLEARPCGFLAG(FileMapped, FILE_MAPPED) TESTPCGFLAG(FileMapped, FILE_MAPPED) -- cgit v1.2.3