diff options
| author | Dave Chinner <dchinner@redhat.com> | 2019-02-12 15:35:55 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-02-20 10:25:47 +0100 |
| commit | 657fbf79a88019807202c849561a25773711e84b (patch) | |
| tree | 7c1b0776d127cd7d2a49951196561b71effadd91 /mm | |
| parent | 8d485d3a628bb46a86f232d9960ef64533aaf29d (diff) | |
Revert "mm: slowly shrink slabs with a relatively small number of objects"
commit a9a238e83fbb0df31c3b9b67003f8f9d1d1b6c96 upstream.
This reverts commit 172b06c32b9497 ("mm: slowly shrink slabs with a
relatively small number of objects").
This change changes the agressiveness of shrinker reclaim, causing small
cache and low priority reclaim to greatly increase scanning pressure on
small caches. As a result, light memory pressure has a disproportionate
affect on small caches, and causes large caches to be reclaimed much
faster than previously.
As a result, it greatly perturbs the delicate balance of the VFS caches
(dentry/inode vs file page cache) such that the inode/dentry caches are
reclaimed much, much faster than the page cache and this drives us into
several other caching imbalance related problems.
As such, this is a bad change and needs to be reverted.
[ Needs some massaging to retain the later seekless shrinker
modifications.]
Link: http://lkml.kernel.org/r/20190130041707.27750-3-david@fromorbit.com
Fixes: 172b06c32b9497 ("mm: slowly shrink slabs with a relatively small number of objects")
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Cc: Wolfgang Walter <linux@stwm.de>
Cc: Roman Gushchin <guro@fb.com>
Cc: Spock <dairinin@gmail.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: <stable@vger.kernel.org>
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@linuxfoundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/vmscan.c | 10 |
1 files changed, 0 insertions, 10 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c index 961401c46334..3830066018c1 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -477,16 +477,6 @@ static unsigned long do_shrink_slab(struct shrink_control *shrinkctl, delta *= 4; do_div(delta, shrinker->seeks); - /* - * Make sure we apply some minimal pressure on default priority - * even on small cgroups. Stale objects are not only consuming memory - * by themselves, but can also hold a reference to a dying cgroup, - * preventing it from being reclaimed. A dying cgroup with all - * corresponding structures like per-cpu stats and kmem caches - * can be really big, so it may lead to a significant waste of memory. - */ - delta = max_t(unsigned long long, delta, min(freeable, batch_size)); - total_scan += delta; if (total_scan < 0) { pr_err("shrink_slab: %pF negative objects to delete nr=%ld\n", |