From mboxrd@z Thu Jan 1 00:00:00 1970 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 7343CC3601A for ; Fri, 4 Apr 2025 01:39:58 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 04A5E6B002C; Thu, 3 Apr 2025 21:39:57 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id F12326B002D; Thu, 3 Apr 2025 21:39:56 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D8D896B002E; Thu, 3 Apr 2025 21:39:56 -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 B56B16B002C for ; Thu, 3 Apr 2025 21:39:56 -0400 (EDT) Received: from smtpin25.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 79324121C60 for ; Fri, 4 Apr 2025 01:39:57 +0000 (UTC) X-FDA: 83294655234.25.71B4C37 Received: from out-179.mta0.migadu.com (out-179.mta0.migadu.com [91.218.175.179]) by imf28.hostedemail.com (Postfix) with ESMTP id D6EF6C0007 for ; Fri, 4 Apr 2025 01:39:55 +0000 (UTC) Authentication-Results: imf28.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=lJr61OEX; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf28.hostedemail.com: domain of shakeel.butt@linux.dev designates 91.218.175.179 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=1743730796; 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=zBVDPRxC7zGlf74XAtJaE4SLulN0IfYjtlemuQUW//g=; b=mSM00W52+mf1CEWwL6gc7oLJ43PD93dlKOXemLdu0WrSrRedJ5lmrZNHwccj4WQTOk0pxA 8sgCD5vOHgmiJ7L4V17LjFWEO229uM5szDfVqA+keylXqXprOxuQSTX5WZNRB/7CkamvoH DqcpNNi+SQeAiK0UO1AoLzFRR0yLoEM= ARC-Authentication-Results: i=1; imf28.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=lJr61OEX; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf28.hostedemail.com: domain of shakeel.butt@linux.dev designates 91.218.175.179 as permitted sender) smtp.mailfrom=shakeel.butt@linux.dev ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1743730796; a=rsa-sha256; cv=none; b=jxfDdHvndecN3Voh6t+hOEKTFWLTqeihT3mv6zobhmXblUk7tBnTx/oEBLNNoExAkYyAm8 RlC+9u8zPVuOJLBYDduppGXusluhRzFFhyfZMX5oDBXYULqUBVs/B9F3MJLuG1KrU+i2xy 6Kf3yP8RoV1m7ON3SA5IV742e0R0u/k= 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=1743730794; 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=zBVDPRxC7zGlf74XAtJaE4SLulN0IfYjtlemuQUW//g=; b=lJr61OEX4xx/9USfw1sohnqhrgFqNhWyygUyfhavSMJTjmL+JpCYHdT4JzRjko3+YFDyoA o3FvDnCdezFhTPYkauE78iHGzVxwYtbUgoDBBCLUDjGvT++701sTPl2fBbo0WZl525k4sd c3sIlCIGT1ABcv3k91f6uLqX/LRI9r0= 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 v2 5/9] memcg: no refilling stock from obj_cgroup_release Date: Thu, 3 Apr 2025 18:39:09 -0700 Message-ID: <20250404013913.1663035-6-shakeel.butt@linux.dev> In-Reply-To: <20250404013913.1663035-1-shakeel.butt@linux.dev> References: <20250404013913.1663035-1-shakeel.butt@linux.dev> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: D6EF6C0007 X-Stat-Signature: dp3a1xh1xfokz3bzbnpr3w5dxqh4fz8o X-Rspam-User: X-HE-Tag: 1743730795-674558 X-HE-Meta: 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 X6krBjka ipTanxaLnZ6GaRJbi4CUnRlqWMYwt6/LyDchQS9jJl6NipTz4IFSqmsbN/c1vpl+jXH8lN5lv4N43qXvA51hoVuFee0Dx8j67J4JGoQw0jY8rXZ6G66KtelohhLIrdUb4PPdJcXllJewMslCId5og2H0zsDdywPZpZSQpsvr+inG6e2WFHqOcdbXWo83U0KWDuzu/78nUgNns41hR9jzv0hvOL2puAYqOmaYo 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. Acked-by: Vlastimil Babka Reviewed-by: Roman Gushchin Signed-off-by: Shakeel Butt --- mm/memcontrol.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 03a2be6d4a67..df52084e90f4 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); + mem_cgroup_put(memcg); + } spin_lock_irqsave(&objcg_lock, flags); list_del(&objcg->list); -- 2.47.1