+ memcg-multi-memcg-percpu-charge-cache-fix.patch added to mm-unstable branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: memcg: multi-memcg percpu charge cache - fix
has been added to the -mm mm-unstable branch.  Its filename is
     memcg-multi-memcg-percpu-charge-cache-fix.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/memcg-multi-memcg-percpu-charge-cache-fix.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Shakeel Butt <shakeel.butt@linux.dev>
Subject: memcg: multi-memcg percpu charge cache - fix
Date: Wed, 23 Apr 2025 15:41:18 -0700

Add BUILD_BUG_ON() for MEMCG_CHARGE_BATCH

Link: https://lkml.kernel.org/r/rlsgeosg3j7v5nihhbxxxbv3xfy4ejvigihj7lkkbt3n6imyne@2apxx2jm2e57
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Eric Dumaze <edumazet@google.com>
Cc: Jakub Kacinski <kuba@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/memcontrol.c |    7 +++++++
 1 file changed, 7 insertions(+)

--- a/mm/memcontrol.c~memcg-multi-memcg-percpu-charge-cache-fix
+++ a/mm/memcontrol.c
@@ -1909,6 +1909,13 @@ static void refill_stock(struct mem_cgro
 	bool evict = true;
 	int i;
 
+	/*
+	 * For now limit MEMCG_CHARGE_BATCH to 127 and less. In future if we
+	 * decide to increase it more than 127 then we will need more careful
+	 * handling of nr_pages[] in struct memcg_stock_pcp.
+	 */
+	BUILD_BUG_ON(MEMCG_CHARGE_BATCH > S8_MAX);
+
 	VM_WARN_ON_ONCE(mem_cgroup_is_root(memcg));
 
 	if (nr_pages > MEMCG_CHARGE_BATCH ||
_

Patches currently in -mm which might be from shakeel.butt@linux.dev are

memcg-vmalloc-simplify-memcg_vmalloc-updates.patch
memcg-vmalloc-simplify-memcg_vmalloc-updates-fix.patch
memcg-remove-root-memcg-check-from-refill_stock.patch
memcg-decouple-drain_obj_stock-from-local-stock.patch
memcg-introduce-memcg_uncharge.patch
memcg-manually-inline-__refill_stock.patch
memcg-no-refilling-stock-from-obj_cgroup_release.patch
memcg-do-obj_cgroup_put-inside-drain_obj_stock.patch
memcg-use-__mod_memcg_state-in-drain_obj_stock.patch
memcg-manually-inline-replace_stock_objcg.patch
memcg-optimize-memcg_rstat_updated.patch
memcg-multi-memcg-percpu-charge-cache.patch
memcg-multi-memcg-percpu-charge-cache-fix.patch
memcg-introduce-non-blocking-limit-setting-option.patch