• Kirill Tkhai's avatar
    mm: add SHRINK_EMPTY shrinker methods return value · 9b996468
    Kirill Tkhai authored
    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.localdomainSigned-off-by: default avatarKirill Tkhai <ktkhai@virtuozzo.com>
    Acked-by: Vladimir Davydov's avatarVladimir Davydov <vdavydov.dev@gmail.com>
    Tested-by: default avatarShakeel Butt <shakeelb@google.com>
    Cc: Al Viro <viro@zeniv.linux.org.uk>
    Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
    Cc: Chris Wilson <chris@chris-wilson.co.uk>
    Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    Cc: Guenter Roeck <linux@roeck-us.net>
    Cc: "Huang, Ying" <ying.huang@intel.com>
    Cc: Johannes Weiner <hannes@cmpxchg.org>
    Cc: Josef Bacik <jbacik@fb.com>
    Cc: Li RongQing <lirongqing@baidu.com>
    Cc: Matthew Wilcox <willy@infradead.org>
    Cc: Matthias Kaehlcke <mka@chromium.org>
    Cc: Mel Gorman <mgorman@techsingularity.net>
    Cc: Michal Hocko <mhocko@kernel.org>
    Cc: Minchan Kim <minchan@kernel.org>
    Cc: Philippe Ombredanne <pombredanne@nexb.com>
    Cc: Roman Gushchin <guro@fb.com>
    Cc: Sahitya Tummala <stummala@codeaurora.org>
    Cc: Stephen Rothwell <sfr@canb.auug.org.au>
    Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Cc: Waiman Long <longman@redhat.com>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    9b996468
super.c 40.8 KB