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 16B73C282EC for ; Fri, 14 Mar 2025 10:17:34 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B1504280007; Fri, 14 Mar 2025 06:17:31 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id AC3DE280002; Fri, 14 Mar 2025 06:17:31 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 98C7D280007; Fri, 14 Mar 2025 06:17:31 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 795B9280002 for ; Fri, 14 Mar 2025 06:17:31 -0400 (EDT) Received: from smtpin14.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 15E325637F for ; Fri, 14 Mar 2025 10:17:33 +0000 (UTC) X-FDA: 83219754786.14.402ACB9 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.223.130]) by imf05.hostedemail.com (Postfix) with ESMTP id B7A08100010 for ; Fri, 14 Mar 2025 10:17:30 +0000 (UTC) Authentication-Results: imf05.hostedemail.com; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=wfpY08Pu; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=yqGeIASK; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=wfpY08Pu; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=yqGeIASK; spf=pass (imf05.hostedemail.com: domain of vbabka@suse.cz designates 195.135.223.130 as permitted sender) smtp.mailfrom=vbabka@suse.cz; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1741947451; 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-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=rFwz+gJLZlMOek5VuKRc/mEh2xiuy371OM7h0EN1qmk=; b=IdE0LbP97QZvkF9xqp/FQUn20HsVT/E4Pwusq3Q5r349KPcInGkvgPNuj2aRJ3/lU5KJBA xFRbOletYGtvPbIqAngac2TYWtMGaNL2fLZjWfJ/6wYWuKhZYeyJhIj8/Fz+lT772+Jnii OTbOCD5EGYMhVeNdaNzrwhgu1LplpDw= ARC-Authentication-Results: i=1; imf05.hostedemail.com; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=wfpY08Pu; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=yqGeIASK; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=wfpY08Pu; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=yqGeIASK; spf=pass (imf05.hostedemail.com: domain of vbabka@suse.cz designates 195.135.223.130 as permitted sender) smtp.mailfrom=vbabka@suse.cz; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1741947451; a=rsa-sha256; cv=none; b=ccStYfYxxKeod0VFeL2AWjlQVaGj9Cvp8G/6l3tHnWpxmC1UOPY5bpDfcEcSITqbrMK9MF bP7NyI9hAOIWp444hINYOUeCfcvOwds37CHPYoad0ZOLz3jXgxnOvYi3ZiG4MoBZ8gIPQ7 zgPoLVgHseK93H4mtx3pAhP+UYOS1Xc= Received: from imap1.dmz-prg2.suse.org (unknown [10.150.64.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 26F9021185; Fri, 14 Mar 2025 10:17:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1741947449; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=rFwz+gJLZlMOek5VuKRc/mEh2xiuy371OM7h0EN1qmk=; b=wfpY08Pux9+iWkKXg+MjBJT1CJ5EOCKXyFkN4Jzmor4ZMqe3yBCnRUtBWE6G527vqcC1gk t0i2Raw6XsU+km4Za93VLm5uiQa6IU2uNljMO4gOlZAmxIjYPYUJlNjSMQ42juPiOejNX0 CI4kggzZrsbGAuGm2m2XcCPxFgjxLuI= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1741947449; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=rFwz+gJLZlMOek5VuKRc/mEh2xiuy371OM7h0EN1qmk=; b=yqGeIASKR5y2z+DLp8wkczZc1LdisO6Sq751Y2XwKVac9O67H+eCI8S+UXdzxLtalmgoFh i3k8rh8h2P4MB7BQ== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1741947449; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=rFwz+gJLZlMOek5VuKRc/mEh2xiuy371OM7h0EN1qmk=; b=wfpY08Pux9+iWkKXg+MjBJT1CJ5EOCKXyFkN4Jzmor4ZMqe3yBCnRUtBWE6G527vqcC1gk t0i2Raw6XsU+km4Za93VLm5uiQa6IU2uNljMO4gOlZAmxIjYPYUJlNjSMQ42juPiOejNX0 CI4kggzZrsbGAuGm2m2XcCPxFgjxLuI= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1741947449; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=rFwz+gJLZlMOek5VuKRc/mEh2xiuy371OM7h0EN1qmk=; b=yqGeIASKR5y2z+DLp8wkczZc1LdisO6Sq751Y2XwKVac9O67H+eCI8S+UXdzxLtalmgoFh i3k8rh8h2P4MB7BQ== Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id EFAF513A31; Fri, 14 Mar 2025 10:17:28 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id 0UTnOTgC1Gc4YgAAD6G6ig (envelope-from ); Fri, 14 Mar 2025 10:17:28 +0000 Message-ID: <0b3ab5e5-e684-44ce-b6ed-276ad37784e6@suse.cz> Date: Fri, 14 Mar 2025 11:17:28 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH 06/10] memcg: do obj_cgroup_put inside drain_obj_stock Content-Language: en-US To: Shakeel Butt , Andrew Morton Cc: Johannes Weiner , Michal Hocko , Roman Gushchin , Muchun Song , Sebastian Andrzej Siewior , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, Meta kernel team References: <20250314061511.1308152-1-shakeel.butt@linux.dev> <20250314061511.1308152-7-shakeel.butt@linux.dev> From: Vlastimil Babka In-Reply-To: <20250314061511.1308152-7-shakeel.butt@linux.dev> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: B7A08100010 X-Stat-Signature: pqtf73jkn6aywh648k8mq8ei8pdyers1 X-HE-Tag: 1741947450-171369 X-HE-Meta: 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 DwhHOsi1 ufxIbVghDORNHvNe3hwA/8VOIACkj7fyQrk7RykQXedt8ONzVixbyXKhC2/aO7cIfKiT16xPmaidDpXAozJByoOoycAZiVo+imd4J9bHh3Yv6t7HTwZjRXpgj0FAFMmpfm+p3utpd8n0ZIfXhR5uWqxU9KXg4F5ArdMlsJuNOKgjwC+sxyu5iEVr72PUjawNnTiuEwbq7+WRgxqs8X8Qp3rV0aRH9rWDvfY3cUTIuKFzn9v/LUvluxudaf1/2TOKvRuHwUCQt74ukdQdZYPq94IeEtsmpclEoTUGUEOK8jZW43EvoqoSFAxj7nW3yqeCHiCKY2WBU8QRAWlQ= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000010, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 3/14/25 07:15, Shakeel Butt wrote: > Previously we could not call obj_cgroup_put() inside the local lock > because on the put on the last reference, the release function > obj_cgroup_release() may try to re-acquire the local lock. However that > chain has been broken. Now simply do obj_cgroup_put() inside > drain_obj_stock() instead of returning the old objcg. > > Signed-off-by: Shakeel Butt Hm is this really safe? I can see obj_cgroup_release() doing percpu_ref_exit() -> kfree(), do we have guaranteed that allocation won't be also in a kmemcg and recurse?