From nobody Sun Dec 14 12:32:36 2025 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) (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 CE31E1DE8A4; Wed, 10 Dec 2025 07:26:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.51 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765351605; cv=none; b=fNCvcHiH1ZfN1lTVoTYp5gg6fkR6KbeIHlSuqupCVaTX86ZbwF0oUGMDak7QyY5E7UojvZ57ByRg9OZ3lekndoUOP2Ycu/yZcNIL1nBw+v8majbhuT+4fiKplbBrTNpDtHDdjWnaU33/T3xHthVRfjFTR0p/FBFKWwMbuTxQg0Y= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765351605; c=relaxed/simple; bh=TWYu5jX7iyHbZtMjImPfNCsO2jUPL7vZzN5I3Pk6hfg=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=TDtpa87KnNDyfkWfHl+0Hi+3mqmIeyQ2DkqiHl1W+RP+Lq2Z3SZDPDEWRM8BJILfePXeMPWJv3ZAhza/eXEfeXrsfYzD0uUuPGPn1iOhQ83mXFldN/Nhq3h7jmIuTPGScEFCOzk3YM0IlPMdaoT5gqFrtZh+xF0jmg02EmXsr8w= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=45.249.212.51 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.93.142]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTPS id 4dR6hw756LzYQtqb; Wed, 10 Dec 2025 15:26:24 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.128]) by mail.maildlp.com (Postfix) with ESMTP id B7B8B1A0359; Wed, 10 Dec 2025 15:26:39 +0800 (CST) Received: from hulk-vt.huawei.com (unknown [10.67.174.121]) by APP4 (Coremail) with SMTP id gCh0CgC33pujIDlpfef4BA--.9918S4; Wed, 10 Dec 2025 15:26:39 +0800 (CST) From: Chen Ridong To: hannes@cmpxchg.org, mhocko@kernel.org, roman.gushchin@linux.dev, shakeel.butt@linux.dev, muchun.song@linux.dev, akpm@linux-foundation.org, axelrasmussen@google.com, yuanchu@google.com, weixugc@google.com, david@kernel.org, zhengqi.arch@bytedance.com, lorenzo.stoakes@oracle.com Cc: cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, lujialin4@huawei.com, chenridong@huaweicloud.com Subject: [PATCH -next v2 2/2] memcg: remove mem_cgroup_size() Date: Wed, 10 Dec 2025 07:11:42 +0000 Message-Id: <20251210071142.2043478-3-chenridong@huaweicloud.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20251210071142.2043478-1-chenridong@huaweicloud.com> References: <20251210071142.2043478-1-chenridong@huaweicloud.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: gCh0CgC33pujIDlpfef4BA--.9918S4 X-Coremail-Antispam: 1UD129KBjvJXoWxur1kur4rXF4kAr47AFWkWFg_yoW5KF4kpF nFk3y3Jw45trW5Gr4aka4UZa4fAa18ta43Jry7Gw18Z3Zxtw1YqF9Fyw18XrWUCF93XF17 Za909r48C3y2y3JanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUmY14x267AKxVWrJVCq3wAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_Jryl82xGYIkIc2 x26xkF7I0E14v26ryj6s0DM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2z4x0 Y4vE2Ix0cI8IcVAFwI0_tr0E3s1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr1j6F4UJw A2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0oVCq3wAS 0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7IYx2 IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4UM4x0 Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwACI402YVCY1x02628vn2kIc2 xKxwCY1x0262kKe7AKxVW8ZVWrXwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWU JVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67 kF1VAFwI0_GFv_WrylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY 6xIIjxv20xvEc7CjxVAFwI0_Cr0_Gr1UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42 IY6I8E87Iv67AKxVWUJVW8JwCI42IY6I8E87Iv6xkF7I0E14v26r4j6r4UJbIYCTnIWIev Ja73UjIFyTuYvjTRNiSHDUUUU X-CM-SenderInfo: hfkh02xlgr0w46kxt4xhlfz01xgou0bp/ Content-Type: text/plain; charset="utf-8" From: Chen Ridong The mem_cgroup_size helper is used only in apply_proportional_protection to read the current memory usage. Its semantics are unclear and inconsistent with other sites, which directly call page_counter_read for the same purpose. Remove this helper and replace its usage with page_counter_read for clarity. Additionally, rename the local variable 'cgroup_size' to 'usage' to better reflect its meaning. This change is safe because page_counter_read() is only called when memcg is enabled in the apply_proportional_protection. No functional changes intended. Signed-off-by: Chen Ridong --- include/linux/memcontrol.h | 7 ------- mm/memcontrol.c | 5 ----- mm/vmscan.c | 8 +++++--- 3 files changed, 5 insertions(+), 15 deletions(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 6a48398a1f4e..bedeb606c691 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -919,8 +919,6 @@ static inline void mem_cgroup_handle_over_high(gfp_t gf= p_mask) =20 unsigned long mem_cgroup_get_max(struct mem_cgroup *memcg); =20 -unsigned long mem_cgroup_size(struct mem_cgroup *memcg); - void mem_cgroup_print_oom_context(struct mem_cgroup *memcg, struct task_struct *p); =20 @@ -1328,11 +1326,6 @@ static inline unsigned long mem_cgroup_get_max(struc= t mem_cgroup *memcg) return 0; } =20 -static inline unsigned long mem_cgroup_size(struct mem_cgroup *memcg) -{ - return 0; -} - static inline void mem_cgroup_print_oom_context(struct mem_cgroup *memcg, struct task_struct = *p) { diff --git a/mm/memcontrol.c b/mm/memcontrol.c index dbe7d8f93072..659ce171b1b3 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1621,11 +1621,6 @@ unsigned long mem_cgroup_get_max(struct mem_cgroup *= memcg) return max; } =20 -unsigned long mem_cgroup_size(struct mem_cgroup *memcg) -{ - return page_counter_read(&memcg->memory); -} - void __memcg_memory_event(struct mem_cgroup *memcg, enum memcg_memory_event event, bool allow_spinning) { diff --git a/mm/vmscan.c b/mm/vmscan.c index 670fe9fae5ba..fe48d0376e7c 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2451,6 +2451,7 @@ static inline void calculate_pressure_balance(struct = scan_control *sc, static unsigned long apply_proportional_protection(struct mem_cgroup *memc= g, struct scan_control *sc, unsigned long scan) { +#ifdef CONFIG_MEMCG unsigned long min, low; =20 mem_cgroup_protection(sc->target_mem_cgroup, memcg, &min, &low); @@ -2485,7 +2486,7 @@ static unsigned long apply_proportional_protection(st= ruct mem_cgroup *memcg, * again by how much of the total memory used is under * hard protection. */ - unsigned long cgroup_size =3D mem_cgroup_size(memcg); + unsigned long usage =3D page_counter_read(&memcg->memory); unsigned long protection; =20 /* memory.low scaling, make sure we retry before OOM */ @@ -2497,9 +2498,9 @@ static unsigned long apply_proportional_protection(st= ruct mem_cgroup *memcg, } =20 /* Avoid TOCTOU with earlier protection check */ - cgroup_size =3D max(cgroup_size, protection); + usage =3D max(usage, protection); =20 - scan -=3D scan * protection / (cgroup_size + 1); + scan -=3D scan * protection / (usage + 1); =20 /* * Minimally target SWAP_CLUSTER_MAX pages to keep @@ -2508,6 +2509,7 @@ static unsigned long apply_proportional_protection(st= ruct mem_cgroup *memcg, */ scan =3D max(scan, SWAP_CLUSTER_MAX); } +#endif return scan; } =20 --=20 2.34.1