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>

diff --git a/include/linux/swap.h b/include/linux/swap.h
index a2602a8207a615ab21abce5f8b0165f90664798d..d8029c2163e4eb9c2582aea630add03fe78e66ba 100644 (file)
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -223,21 +223,11 @@ static inline void lru_cache_add_anon(struct page *page)
        __lru_cache_add(page, LRU_INACTIVE_ANON);
 }
 
-static inline void lru_cache_add_active_anon(struct page *page)
-{
-       __lru_cache_add(page, LRU_ACTIVE_ANON);
-}
-
 static inline void lru_cache_add_file(struct page *page)
 {
        __lru_cache_add(page, LRU_INACTIVE_FILE);
 }
 
-static inline void lru_cache_add_active_file(struct page *page)
-{
-       __lru_cache_add(page, LRU_ACTIVE_FILE);
-}
-
 /* linux/mm/vmscan.c */
 extern unsigned long try_to_free_pages(struct zonelist *zonelist, int order,
                                        gfp_t gfp_mask, nodemask_t *mask);

diff --git a/mm/filemap.c b/mm/filemap.c
index 698ea80f21022bf709dacc1101c614327109d828..3dce0107262f91092ce3baa778cb3031365524f0 100644 (file)
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -441,7 +441,7 @@ int add_to_page_cache_lru(struct page *page, struct address_space *mapping,
        /*
         * Splice_read and readahead add shmem/tmpfs pages into the page cache
         * before shmem_readpage has a chance to mark them as SwapBacked: they
-        * need to go on the active_anon lru below, and mem_cgroup_cache_charge
+        * need to go on the anon lru below, and mem_cgroup_cache_charge
         * (called in add_to_page_cache) needs to know where they're going too.
         */
        if (mapping_cap_swap_backed(mapping))
@@ -452,7 +452,7 @@ int add_to_page_cache_lru(struct page *page, struct address_space *mapping,
                if (page_is_file_cache(page))
                        lru_cache_add_file(page);
                else
-                       lru_cache_add_active_anon(page);
+                       lru_cache_add_anon(page);
        }
        return ret;
 }