[failures] mm-zswap-mark-the-zswap-shrinker-shrinker_nonslab.patch removed from -mm tree

[failures] mm-zswap-mark-the-zswap-shrinker-shrinker_nonslab.patch removed from -mm tree

[Andrew Morton]

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The quilt patch titled
     Subject: mm: zswap: mark the zswap shrinker SHRINKER_NONSLAB
has been removed from the -mm tree.  Its filename was
     mm-zswap-mark-the-zswap-shrinker-shrinker_nonslab.patch

This patch was dropped because it had testing failures

------------------------------------------------------
From: Qinyun Tan <qinyuntan@linux.alibaba.com>
Subject: mm: zswap: mark the zswap shrinker SHRINKER_NONSLAB
Date: Thu, 10 Sep 2026 16:07:22 +0800

With kmem accounting disabled (cgroup.memory=nokmem), memcg reclaim never
invokes the zswap shrinker: a cgroup under memory pressure does not write
back its own zswapped pages to make room; they are only written back by
global reclaim or once the global pool limit kicks in.

The zswap shrinker is registered memcg-aware but without SHRINKER_NONSLAB,
so under nokmem it is treated as a slab shrinker: before commit
03375203e1da ("mm: do not allocate shrinker info with
cgroup.memory=nokmem") it was skipped by the !memcg_kmem_online() check in
shrink_slab_memcg(); since that commit it is demoted to non-memcg-aware at
registration.  But the zswap shrinker is not a slab shrinker: it tracks
zswap entries and resolves the owning memcg from the folio's objcg,
independent of kmem accounting.

This was noticed by Michal during review of the patch "mm/list_lru: don't
copy stale shrinker id from non-memcg-aware shrinkers" [1].

Mark it SHRINKER_NONSLAB so it keeps its memcg awareness and runs under
memcg reclaim with nokmem.

Link: https://lore.kernel.org/20260910080722.3961351-5-qinyuntan@linux.alibaba.com
Link: https://lore.kernel.org/lkml/697713c4-0857-485b-aba7-c74f37a3c8b4@linux.alibaba.com/ [1]
Fixes: b5ba474f3f51 ("zswap: shrink zswap pool based on memory pressure")
Signed-off-by: Qinyun Tan <qinyuntan@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Suggested-by: Michal Koutný <mkoutny@suse.com>
Acked-by: Usama Arif <usama.arif@linux.dev>
Acked-by: Nhat Pham <nphamcs@gmail.com>
Acked-by: Yosry Ahmed <yosry@kernel.org>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: David Hildenbrand <david@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Qi Zheng <qi.zheng@linux.dev>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Xunlei Pang <xlpang@linux.alibaba.com>
Cc: Kairui Song <ryncsn@gmail.com>
---

 mm/zswap.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/mm/zswap.c~mm-zswap-mark-the-zswap-shrinker-shrinker_nonslab
+++ a/mm/zswap.c
@@ -1297,8 +1297,8 @@ static struct shrinker *zswap_alloc_shri
 {
 	struct shrinker *shrinker;
 
-	shrinker =
-		shrinker_alloc(SHRINKER_NUMA_AWARE | SHRINKER_MEMCG_AWARE, "mm-zswap");
+	shrinker = shrinker_alloc(SHRINKER_NUMA_AWARE | SHRINKER_MEMCG_AWARE |
+				  SHRINKER_NONSLAB, "mm-zswap");
 	if (!shrinker)
 		return NULL;
 
_

Patches currently in -mm which might be from qinyuntan@linux.alibaba.com are

mm-list_lru-disable-memcg-awareness-under-cgroup_disable=memory.patch
mm-list_lru-dont-copy-stale-shrinker-id-from-non-memcg-aware-shrinkers.patch