]> git.kernelconcepts.de Git - karo-tx-linux.git/commit
tmpfs: insert tmpfs cache pages to inactive list at first
authorKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Mon, 24 May 2010 21:31:48 +0000 (14:31 -0700)
committerGreg Kroah-Hartman <gregkh@suse.de>
Mon, 5 Jul 2010 18:22:29 +0000 (11:22 -0700)
commit3bbcbb8c48b2e8e7afa7795161807c1a43b7c02c
treea59f6269b7fd5550373a1dd2b1507d2402fd5931
parent6e9fe9b3f0408bb6b54873c00e7182513f55490b
tmpfs: insert tmpfs cache pages to inactive list at first

commit e9d6c157385e4efa61cb8293e425c9d8beba70d3 upstream.

Shaohua Li reported parallel file copy on tmpfs can lead to OOM killer.
This is regression of caused by commit 9ff473b9a7 ("vmscan: evict
streaming IO first").  Wow, It is 2 years old patch!

Currently, tmpfs file cache is inserted active list at first.  This means
that the insertion doesn't only increase numbers of pages in anon LRU, but
it also reduces anon scanning ratio.  Therefore, vmscan will get totally
confused.  It scans almost only file LRU even though the system has plenty
unused tmpfs pages.

Historically, lru_cache_add_active_anon() was used for two reasons.
1) Intend to priotize shmem page rather than regular file cache.
2) Intend to avoid reclaim priority inversion of used once pages.

But we've lost both motivation because (1) Now we have separate anon and
file LRU list.  then, to insert active list doesn't help such priotize.
(2) In past, one pte access bit will cause page activation.  then to
insert inactive list with pte access bit mean higher priority than to
insert active list.  Its priority inversion may lead to uninteded lru
chun.  but it was already solved by commit 645747462 (vmscan: detect
mapped file pages used only once).  (Thanks Hannes, you are great!)

Thus, now we can use lru_cache_add_anon() instead.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reported-by: Shaohua Li <shaohua.li@intel.com>
Reviewed-by: Wu Fengguang <fengguang.wu@intel.com>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
include/linux/swap.h
mm/filemap.c