From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8AC1D3F6C30 for ; Fri, 9 Oct 2026 05:56:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791525416; cv=none; b=Zg7x+qI2uShoGboPb+4tn7xIPRfCh3pNqMxUPeYSkhs2qXKzL0tE3liQImG9FzLyEXz6xxVMZytI2n3i0rQxIUXps08k0xwoYTVJs+e5gvldjjNEoMSVBV+JL895jFmkYgW9lerxkXP+F29GQFAKWnLiTefRaKT9YNQbADMRyJ0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791525416; c=relaxed/simple; bh=l/Nw/0dazvflnUn14y36lmtzUoOm4/IMrUOTrvq60bY=; h=Date:To:From:Subject:Message-Id; b=lBSVwacUQ46mo97x6ZVyq5D7u4YUFMVzGxLueItfJG9zdpbwwnSbkYfAkHWQ83ZxYHSaGFUGQnDsODXET4AHaR7XON61F7XdhKVAsR4szhM0M4nBFwkEaVGcoZn3mB4tIJ8jjOU6GKCzhanZCTkOMtiIqmKW3VkNboD+0ymgzpg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=TUHpiyG6; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="TUHpiyG6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 619AB1F000FF; Fri, 9 Oct 2026 05:56:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1791525415; bh=1TQ91HML4jgC6U3mmdb25xuj66pfA2dXe90cGmbNJjY=; h=Date:To:From:Subject; b=TUHpiyG6+frgFR0ev7+zE5rSe9O6jJzvjz7uZDzxE6yL1Ias5sXjFMZ+UYJg6n3nt leruGMoWOyoD0zdDbxuyLlnpL4kAKlcC8FYaW6g00KbBRGzzZ9QfRJZzl1W9EVDqEy 9gWqVUBrQdg4A22swJlkUExHd3PTUzpWr5HXFT3s= Date: Thu, 08 Oct 2026 22:56:55 -0700 To: mm-commits@vger.kernel.org,roman.gushchin@linux.dev,muchun.song@linux.dev,mhocko@kernel.org,hannes@cmpxchg.org,shakeel.butt@linux.dev,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] memcg-group-the-read-mostly-fields-of-struct-mem_cgroup.patch removed from -mm tree Message-Id: <20261009055655.619AB1F000FF@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: memcg: group the read-mostly fields of struct mem_cgroup has been removed from the -mm tree. Its filename was memcg-group-the-read-mostly-fields-of-struct-mem_cgroup.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: Shakeel Butt Subject: memcg: group the read-mostly fields of struct mem_cgroup Date: Fri, 4 Sep 2026 20:05:21 -0700 These fields are set when the memcg is created and only read after that: vmstats_percpu read on every stat update vmstats zswap_max, zswap_writeback private_id read on every eviction and refault kmemcg_id read on every list_lru lookup oom_group Put them in one cache line group at the end of the struct, right before nodeinfo[]. nodeinfo[] is read-mostly too but it is a flexible array, so it cannot sit inside a group. The group ends without padding so the two share a line. This also drops the ____cacheline_aligned_in_smp on vmstats_percpu added by commit c1afbd5de131 ("mm/memcontrol: avoid false sharing between vmstats and events"). That only aligned the start of the field. cgwb_domain followed it on the same line and is written on every writeout completion. A group boundary covers both sides. No functional change. Link: https://lore.kernel.org/20260905030522.1887837-6-shakeel.butt@linux.dev Signed-off-by: Shakeel Butt Signed-off-by: Andrew Morton Cc: Johannes Weiner Cc: Michal Hocko Cc: Muchun Song Cc: Roman Gushchin --- include/linux/memcontrol.h | 62 +++++++++++++++++++---------------- mm/memcontrol.c | 17 +++++++++ 2 files changed, 52 insertions(+), 27 deletions(-) --- a/include/linux/memcontrol.h~memcg-group-the-read-mostly-fields-of-struct-mem_cgroup +++ a/include/linux/memcontrol.h @@ -183,9 +183,6 @@ struct obj_cgroup { struct mem_cgroup { struct cgroup_subsys_state css; - /* Private memcg ID. Used to ID objects that outlive the cgroup */ - int private_id; - /* Accounted resources */ struct page_counter memory; /* Both v1 & v2 */ @@ -259,30 +256,6 @@ struct mem_cgroup { #endif __cacheline_group_end_aligned(memcg_cold); -#ifdef CONFIG_ZSWAP - unsigned long zswap_max; - - /* - * Prevent pages from this memcg from being written back from zswap to - * swap, and from being swapped out on zswap store failures. - */ - bool zswap_writeback; -#endif - - /* - * Should the OOM killer kill all belonging tasks, had it kill one? - */ - bool oom_group; - - /* memory.stat */ - struct memcg_vmstats *vmstats; - - int kmemcg_id; - - /* Keep the hot per-CPU stats pointer away from memory event counters. */ - struct memcg_vmstats_percpu __percpu *vmstats_percpu - ____cacheline_aligned_in_smp; - #ifdef CONFIG_MEMCG_V1 /* v1 only. Not grouped: v1 is legacy, sorting it is not worth it. */ @@ -322,6 +295,41 @@ struct mem_cgroup { int swappiness; #endif /* CONFIG_MEMCG_V1 */ + /* + * Set when the memcg is created and cleared when it is offlined. + * Never written on a hot path. + */ + __cacheline_group_begin_aligned(memcg_read_mostly); + /* Read on every stat update */ + struct memcg_vmstats_percpu __percpu *vmstats_percpu; + + /* memory.stat */ + struct memcg_vmstats *vmstats; + +#ifdef CONFIG_ZSWAP + unsigned long zswap_max; +#endif + + /* Private memcg ID. Used to ID objects that outlive the cgroup */ + int private_id; + + int kmemcg_id; + + /* + * Should the OOM killer kill all belonging tasks, had it kill one? + */ + bool oom_group; + +#ifdef CONFIG_ZSWAP + /* + * Prevent pages from this memcg from being written back from zswap to + * swap, and from being swapped out on zswap store failures. + */ + bool zswap_writeback; +#endif + /* Not padded: nodeinfo[] is read-mostly too, let it share the line. */ + __cacheline_group_end(memcg_read_mostly); + struct mem_cgroup_per_node *nodeinfo[]; }; --- a/mm/memcontrol.c~memcg-group-the-read-mostly-fields-of-struct-mem_cgroup +++ a/mm/memcontrol.c @@ -5753,6 +5753,23 @@ static void __init memcg_struct_check(vo CACHELINE_ASSERT_GROUP_MEMBER(struct mem_cgroup, memcg_cold, mm_list); #endif + + CACHELINE_ASSERT_GROUP_MEMBER(struct mem_cgroup, memcg_read_mostly, + vmstats_percpu); + CACHELINE_ASSERT_GROUP_MEMBER(struct mem_cgroup, memcg_read_mostly, + vmstats); +#ifdef CONFIG_ZSWAP + CACHELINE_ASSERT_GROUP_MEMBER(struct mem_cgroup, memcg_read_mostly, + zswap_max); + CACHELINE_ASSERT_GROUP_MEMBER(struct mem_cgroup, memcg_read_mostly, + zswap_writeback); +#endif + CACHELINE_ASSERT_GROUP_MEMBER(struct mem_cgroup, memcg_read_mostly, + private_id); + CACHELINE_ASSERT_GROUP_MEMBER(struct mem_cgroup, memcg_read_mostly, + kmemcg_id); + CACHELINE_ASSERT_GROUP_MEMBER(struct mem_cgroup, memcg_read_mostly, + oom_group); } int __init mem_cgroup_init(void) _ Patches currently in -mm which might be from shakeel.butt@linux.dev are