From patchwork Sat Mar 15 17:49:26 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shakeel Butt X-Patchwork-Id: 14018168 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 73369C28B2F for ; Sat, 15 Mar 2025 17:50:01 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 3A4B8280007; Sat, 15 Mar 2025 13:49:59 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 32D11280001; Sat, 15 Mar 2025 13:49:59 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1CF2F280007; Sat, 15 Mar 2025 13:49:59 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id F0896280001 for ; Sat, 15 Mar 2025 13:49:58 -0400 (EDT) Received: from smtpin19.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 66022141E48 for ; Sat, 15 Mar 2025 17:50:00 +0000 (UTC) X-FDA: 83224523760.19.1545B73 Received: from out-180.mta0.migadu.com (out-180.mta0.migadu.com [91.218.175.180]) by imf24.hostedemail.com (Postfix) with ESMTP id B59CB180004 for ; Sat, 15 Mar 2025 17:49:58 +0000 (UTC) Authentication-Results: imf24.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b="e/E/nuyl"; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf24.hostedemail.com: domain of shakeel.butt@linux.dev designates 91.218.175.180 as permitted sender) smtp.mailfrom=shakeel.butt@linux.dev ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1742060998; a=rsa-sha256; cv=none; b=gPQA4CjlxpYX3MaccQmrhwS3tcZw+kfJewSCwJwREpDqMKeUy9iYyc6lUqQ+0EMgOjFppr mwCImPeQCVq8A9Bb3bBwjuOqu9HF81lOH1ueqofCKF/rU/Mpl/G1GmS+KnGhoXaDjspf2p RGzoIMSppH9d1+VOZSvY52k48cMdqFs= ARC-Authentication-Results: i=1; imf24.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b="e/E/nuyl"; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf24.hostedemail.com: domain of shakeel.butt@linux.dev designates 91.218.175.180 as permitted sender) smtp.mailfrom=shakeel.butt@linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1742060998; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=6mWjPqT680ajW18j1m0PlnxhJw6Nvx3pVB+w31Bj7so=; b=r2IKtj3MnM3EO+w+09YO2GZK7SqAIuKot6Ekj8+KEoWXZ1o2591V5JC7ksOl1z+Cg08xKj +toI06ivrqBSp0iJ1FpXX/MJAzgernhtl85AuiT/Os3tv9lU96FDSxqsvLSUaIkGKdqHQv SGMBym6CjMHGFz+Pk2gZhulN/C2iUAA= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1742060997; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=6mWjPqT680ajW18j1m0PlnxhJw6Nvx3pVB+w31Bj7so=; b=e/E/nuylkpGXEhqHZNEobS6G+bqcssykgUckBO75NlFgK87SEgIBgQphktZTteBqNnHTbd x6QCYzHUjbLCNKPRZeaMdVcSSLOj6sGoyZmm+1mDUtiEh8IruX1fojGN/FiLHsrwdIn2s5 f2gone2vSuXSW8gupsMmoVL5SC2w8ho= From: Shakeel Butt To: Andrew Morton Cc: Johannes Weiner , Michal Hocko , Roman Gushchin , Muchun Song , Vlastimil Babka , Sebastian Andrzej Siewior , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, Meta kernel team Subject: [PATCH 5/9] memcg: no refilling stock from obj_cgroup_release Date: Sat, 15 Mar 2025 10:49:26 -0700 Message-ID: <20250315174930.1769599-6-shakeel.butt@linux.dev> In-Reply-To: <20250315174930.1769599-1-shakeel.butt@linux.dev> References: <20250315174930.1769599-1-shakeel.butt@linux.dev> MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT X-Rspam-User: X-Rspamd-Queue-Id: B59CB180004 X-Rspamd-Server: rspam05 X-Stat-Signature: pmjnf6ux8ei5ikrtr54xm6a4ob8j9whc X-HE-Tag: 1742060998-895501 X-HE-Meta: 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 0xVr4VUz U50mGN014L4fzXeRG7OuNVkZGpzqsaE5yHwNezQDiiMEEIXs2c8TL1Q5P0evshQ+/cz5KNzshfOQ8/TGmhGWZn3IET6eN7VZTmHteXOtXGz6qIxRxo5VO8TGFLML8js2wpFV5/V4Q4yp59/XfKRAqfIy5A3/oBrrPjsxLSWO2OYdABIuyQDu3d4nkNvlKz2LqiH34it6pnNJsMXE3aMaavkYXFe5+Vz+WMEX5 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: obj_cgroup_release is called when all the references to the objcg have been released i.e. no more memory objects are pointing to it. Most probably objcg->memcg will be pointing to some ancestor memcg. In obj_cgroup_release(), the kernel calls obj_cgroup_uncharge_pages() which refills the local stock. There is no need to refill the local stock with some ancestor memcg and flush the local stock. Let's decouple obj_cgroup_release() from the local stock by uncharging instead of refilling. One additional benefit of this change is that it removes the requirement to only call obj_cgroup_put() outside of local_lock. Signed-off-by: Shakeel Butt Acked-by: Vlastimil Babka --- mm/memcontrol.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 7054b0ebd207..83db180455a1 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -129,8 +129,7 @@ bool mem_cgroup_kmem_disabled(void) return cgroup_memory_nokmem; } -static void obj_cgroup_uncharge_pages(struct obj_cgroup *objcg, - unsigned int nr_pages); +static void memcg_uncharge(struct mem_cgroup *memcg, unsigned int nr_pages); static void obj_cgroup_release(struct percpu_ref *ref) { @@ -163,8 +162,16 @@ static void obj_cgroup_release(struct percpu_ref *ref) WARN_ON_ONCE(nr_bytes & (PAGE_SIZE - 1)); nr_pages = nr_bytes >> PAGE_SHIFT; - if (nr_pages) - obj_cgroup_uncharge_pages(objcg, nr_pages); + if (nr_pages) { + struct mem_cgroup *memcg; + + memcg = get_mem_cgroup_from_objcg(objcg); + mod_memcg_state(memcg, MEMCG_KMEM, -nr_pages); + memcg1_account_kmem(memcg, -nr_pages); + if (!mem_cgroup_is_root(memcg)) + memcg_uncharge(memcg, nr_pages); + css_put(&memcg->css); + } spin_lock_irqsave(&objcg_lock, flags); list_del(&objcg->list);