From 9b996468cfdba09f688f52dba4287de596194613 Mon Sep 17 00:00:00 2001 From: Kirill Tkhai Date: Fri, 17 Aug 2018 15:48:21 -0700 Subject: mm: add SHRINK_EMPTY shrinker methods return value We need to distinguish the situations when shrinker has very small amount of objects (see vfs_pressure_ratio() called from super_cache_count()), and when it has no objects at all. Currently, in the both of these cases, shrinker::count_objects() returns 0. The patch introduces new SHRINK_EMPTY return value, which will be used for "no objects at all" case. It's is a refactoring mostly, as SHRINK_EMPTY is replaced by 0 by all callers of do_shrink_slab() in this patch, and all the magic will happen in further. Link: http://lkml.kernel.org/r/153063069574.1818.11037751256699341813.stgit@localhost.localdomain Signed-off-by: Kirill Tkhai Acked-by: Vladimir Davydov Tested-by: Shakeel Butt Cc: Al Viro Cc: Andrey Ryabinin Cc: Chris Wilson Cc: Greg Kroah-Hartman Cc: Guenter Roeck Cc: "Huang, Ying" Cc: Johannes Weiner Cc: Josef Bacik Cc: Li RongQing Cc: Matthew Wilcox Cc: Matthias Kaehlcke Cc: Mel Gorman Cc: Michal Hocko Cc: Minchan Kim Cc: Philippe Ombredanne Cc: Roman Gushchin Cc: Sahitya Tummala Cc: Stephen Rothwell Cc: Tetsuo Handa Cc: Thomas Gleixner Cc: Waiman Long Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/super.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'fs') diff --git a/fs/super.c b/fs/super.c index f5f96e52e0cd..7429588d6b49 100644 --- a/fs/super.c +++ b/fs/super.c @@ -144,6 +144,9 @@ static unsigned long super_cache_count(struct shrinker *shrink, total_objects += list_lru_shrink_count(&sb->s_dentry_lru, sc); total_objects += list_lru_shrink_count(&sb->s_inode_lru, sc); + if (!total_objects) + return SHRINK_EMPTY; + total_objects = vfs_pressure_ratio(total_objects); return total_objects; } -- cgit v1.2.3