From: Andrew Morton <akpm@linux-foundation.org>
To: mm-commits@vger.kernel.org,yuanchu@google.com,weixugc@google.com,stable@vger.kernel.org,shikemeng@huaweicloud.com,shakeel.butt@linux.dev,roman.gushchin@linux.dev,qi.zheng@linux.dev,nphamcs@gmail.com,muchun.song@linux.dev,mhocko@kernel.org,ljs@kernel.org,kasong@tencent.com,husong@kylinos.cn,hannes@cmpxchg.org,david@kernel.org,dave@stgolabs.net,chrisl@kernel.org,baoquan.he@linux.dev,baohua@kernel.org,axelrasmussen@google.com,chenridong@xiaomi.com,akpm@linux-foundation.org
Subject: [merged mm-stable] mm-vmscan-fix-node-reclaim-ignoring-swappiness-parameter.patch removed from -mm tree
Date: Mon, 24 Aug 2026 18:45:11 -0700 [thread overview]
Message-ID: <20260825014512.4CF6D1F00A3A@smtp.kernel.org> (raw)
The quilt patch titled
Subject: mm: vmscan: fix node reclaim ignoring swappiness parameter
has been removed from the -mm tree. Its filename was
mm-vmscan-fix-node-reclaim-ignoring-swappiness-parameter.patch
This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: Ridong Chen <chenridong@xiaomi.com>
Subject: mm: vmscan: fix node reclaim ignoring swappiness parameter
Date: Thu, 23 Jul 2026 11:24:34 +0800
sc_swappiness() had two separate definitions depending on CONFIG_MEMCG.
The !CONFIG_MEMCG variant simply returned vm_swappiness, ignoring the
proactive_swappiness value passed through scan_control. This caused the
swappiness parameter written to /sys/devices/system/node/nodeX/reclaim to
have no effect when CONFIG_MEMCG is disabled.
Fix this by consolidating sc_swappiness() into a single definition that
checks sc->proactive_swappiness first, then falls back to
mem_cgroup_swappiness() which already handles both CONFIG_MEMCG and
!CONFIG_MEMCG.
Before fix (swappiness=max ignored, mostly file pages reclaimed):
# cat /proc/sys/vm/swappiness
60
# cat /proc/vmstat | grep pgsteal
pgsteal_kswapd 0
pgsteal_direct 0
pgsteal_khugepaged 0
pgsteal_proactive 1840
pgsteal_anon 25
pgsteal_file 1815
# echo "64M swappiness=max" > /sys/devices/system/node/node0/reclaim
# cat /proc/vmstat | grep pgsteal
pgsteal_kswapd 0
pgsteal_direct 0
pgsteal_khugepaged 0
pgsteal_proactive 18013
pgsteal_anon 337
pgsteal_file 17676
After fix (swappiness=max honored, anon pages reclaimed as expected):
# cat /proc/vmstat | grep pgsteal
pgsteal_kswapd 0
pgsteal_direct 0
pgsteal_khugepaged 0
pgsteal_proactive 0
pgsteal_anon 0
pgsteal_file 0
# echo "64M swappiness=max" > /sys/devices/system/node/node0/reclaim
# cat /proc/vmstat | grep pgsteal
pgsteal_kswapd 0
pgsteal_direct 0
pgsteal_khugepaged 0
pgsteal_proactive 16283
pgsteal_anon 16283
pgsteal_file 0
Link: https://lore.kernel.org/20260723032434.2016749-3-ridong.chen@linux.dev
Fixes: b980077899ea ("mm: introduce per-node proactive reclaim interface")
Signed-off-by: Ridong Chen <chenridong@xiaomi.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Barry Song <baohua@kernel.org>
Acked-by: Qi Zheng <qi.zheng@linux.dev>
Tested-by: Song Hu <husong@kylinos.cn>
Reviewed-by: Song Hu <husong@kylinos.cn>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Chris Li <chrisl@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Wei Xu <weixugc@google.com>
Cc: Yuanchu Xie <yuanchu@google.com>
Cc: <stable@vger.kernel.org> [6.17+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
mm/vmscan.c | 19 +++++++------------
1 file changed, 7 insertions(+), 12 deletions(-)
--- a/mm/vmscan.c~mm-vmscan-fix-node-reclaim-ignoring-swappiness-parameter
+++ a/mm/vmscan.c
@@ -199,6 +199,13 @@ struct scan_control {
*/
int vm_swappiness = 60;
+static int sc_swappiness(struct scan_control *sc, struct mem_cgroup *memcg)
+{
+ if (sc->proactive && sc->proactive_swappiness)
+ return *sc->proactive_swappiness;
+ return mem_cgroup_swappiness(memcg);
+}
+
#ifdef CONFIG_MEMCG
/* Returns true for reclaim through cgroup limits or cgroup interfaces. */
@@ -239,13 +246,6 @@ static bool writeback_throttling_sane(st
#endif
return false;
}
-
-static int sc_swappiness(struct scan_control *sc, struct mem_cgroup *memcg)
-{
- if (sc->proactive && sc->proactive_swappiness)
- return *sc->proactive_swappiness;
- return mem_cgroup_swappiness(memcg);
-}
#else
static bool cgroup_reclaim(struct scan_control *sc)
{
@@ -261,11 +261,6 @@ static bool writeback_throttling_sane(st
{
return true;
}
-
-static int sc_swappiness(struct scan_control *sc, struct mem_cgroup *memcg)
-{
- return READ_ONCE(vm_swappiness);
-}
#endif
static inline bool is_exec_file_folio(const struct folio *folio,
_
Patches currently in -mm which might be from chenridong@xiaomi.com are
reply other threads:[~2026-08-25 1:45 UTC|newest]
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