The patch titled
Subject: Revert "mm: slowly shrink slabs with a relatively small number of objects"
has been added to the -mm tree. Its filename is
revert-mm-slowly-shrink-slabs-with-a-relatively-small-number-of-objects.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/revert-mm-slowly-shrink-slabs-with-a-relatively-small-number-of-objects.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/revert-mm-slowly-shrink-slabs-with-a-relatively-small-number-of-objects.patch
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------------------------------------------------------
From: Dave Chinner <dchinner@xxxxxxxxxx>
Subject: Revert "mm: slowly shrink slabs with a relatively small number of objects"
This reverts commit 172b06c32b949759fe6313abec514bc4f15014f4.
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@xxxxxxxxxxxxx
Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx>
Cc: Roman Gushchin <guro@xxxxxx>
Cc: Spock <dairinin@xxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
--- a/mm/vmscan.c~revert-mm-slowly-shrink-slabs-with-a-relatively-small-number-of-objects
+++ a/mm/vmscan.c
@@ -491,16 +491,6 @@ static unsigned long do_shrink_slab(stru
delta = freeable / 2;
}
- /*
- * 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",
_
Patches currently in -mm which might be from dchinner@xxxxxxxxxx are
revert-mm-dont-reclaim-inodes-with-many-attached-pages.patch
revert-mm-slowly-shrink-slabs-with-a-relatively-small-number-of-objects.patch
