Received: by 2002:a05:6a10:6d25:0:0:0:0 with SMTP id gq37csp145759pxb; Sat, 11 Sep 2021 00:43:30 -0700 (PDT) X-Google-Smtp-Source: ABdhPJy6X7+dAlJZ+0wgroShfiUYk3ZFZFyfSGzqKWjEtvBWTmjbcgKQM0BpjqyVXQacevBDFgDj X-Received: by 2002:a17:906:5acb:: with SMTP id x11mr1443369ejs.514.1631346210293; Sat, 11 Sep 2021 00:43:30 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1631346210; cv=none; d=google.com; s=arc-20160816; b=F9dL4Yh5+A0DGa6Qore9mglXn+lUZZoYtSb6f8umzGFj550rBaBKMftqZYURtg6mCf bcYsYlSUH7FF1N9dGfP9qC6gzDdDjNXXlzGD6msuYUT1IvcIe3R9mxmUuRPf23IFfBcz oSHjVokJG5zZKB1z0zUdb7z9dU57mEymsNOjANX4fY7QKM7Bb0urhlYzZT4I4WaDOUAZ ke1S1oktYA0Jik1W3EBOul2rC0BZaxEA9BBIynwSODHmdGPeVxW4/sqf09u4Zl8T8nN5 WzG1F8PBGxJOLrq+CFaq9wxDONg1GSjWbPIn4B3fvduSdlQVsInWncnrnbiO3z7naV5A iVjg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:content-language :mime-version:user-agent:date:message-id:cc:to:subject:from :dkim-signature; bh=Sj1B4dxxEgCYUObVr5tn3EBz2yvfW+//sFIcOOUDc5U=; b=Ah9qb14HHa1DrroR6/9FtOMngKY0d0lsoDUz/KrbM5Cg58tYRGyWuy7fJzNgo3RuhG DKxonnELP35ZOgFqojCmPBb2BlULAV7mqX1UoiUoresMRr0lTIa4RII4i9/J6rGk3Vk1 Xa5Q2d65gbqyaNXxHaANfEnb8l7HadtQUbdVeO8/BWG/sMsiZmQwY0JyMO43lWiOHb5T 00dxw0rpwIlVIlLamGAi7UlfBQ0wURVUqGMsVb5lQAkkOH1QiFCA5BNTae9RT4xbqk/r EzP/roYxbCFyc1EpUPDjIjWP/roXtyinZN0It2dPo4bAJE3HShlWvyAlyo302qcrI1hL Lm5g== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@virtuozzo.com header.s=relay header.b=SUiOHBCK; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=virtuozzo.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id qa36si1241650ejc.337.2021.09.11.00.43.06; Sat, 11 Sep 2021 00:43:30 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@virtuozzo.com header.s=relay header.b=SUiOHBCK; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=virtuozzo.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235388AbhIKHlZ (ORCPT + 99 others); Sat, 11 Sep 2021 03:41:25 -0400 Received: from relay.sw.ru ([185.231.240.75]:43196 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235384AbhIKHlY (ORCPT ); Sat, 11 Sep 2021 03:41:24 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=virtuozzo.com; s=relay; h=Content-Type:MIME-Version:Date:Message-ID:Subject :From; bh=Sj1B4dxxEgCYUObVr5tn3EBz2yvfW+//sFIcOOUDc5U=; b=SUiOHBCKVqMzFtBCHuo +yEezW7VXZzWxFfxvZosB5l1ohptlc/j68xDJ/3kIXPlYJhoBSeNVe4QD0JhinidYSrsN4t7/7h5P gb8CBcZz1ZoSDepWoa+IZWpsc2wLZd0Mj3DFK0TK2g3mhmgH48DiFhaiJVGWM9v6VZ4Nt1uMKUs=; Received: from [10.93.0.56] by relay.sw.ru with esmtp (Exim 4.94.2) (envelope-from ) id 1mOxcP-001awD-Ot; Sat, 11 Sep 2021 10:40:09 +0300 From: Vasily Averin Subject: [PATCH] ipc: remove memcg accounting for sops objects in do_semtimedop() To: Andrew Morton Cc: Linus Torvalds , Shakeel Butt , linux-kernel@vger.kernel.org, Michal Hocko , Johannes Weiner , kernel@openvz.org, cgroups@vger.kernel.org Message-ID: <90e254df-0dfe-f080-011e-b7c53ee7fd20@virtuozzo.com> Date: Sat, 11 Sep 2021 10:40:08 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Linus proposes to revert an accounting for sops objects in do_semtimedop() because it's really just a temporary buffer for a single semtimedop() system call. This object can consume up to 2 pages, syscall is sleeping one, size and duration can be controlled by user, and this allocation can be repeated by many thread at the same time. However Shakeel Butt pointed that there are much more popular objects with the same life time and similar memory consumption, the accounting of which was decided to be rejected for performance reasons. In addition, any usual task consumes much more accounted memory, so 2 pages of this temporal buffer can be safely ignored. Link: https://patchwork.kernel.org/project/linux-fsdevel/patch/20171005222144.123797-1-shakeelb@google.com/ Fixes: 18319498fdd4 ("memcg: enable accounting of ipc resources") Signed-off-by: Vasily Averin --- ipc/sem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/ipc/sem.c b/ipc/sem.c index f833238df1ce..6693daf4fe11 100644 --- a/ipc/sem.c +++ b/ipc/sem.c @@ -2238,7 +2238,7 @@ static long do_semtimedop(int semid, struct sembuf __user *tsops, return -EINVAL; if (nsops > SEMOPM_FAST) { - sops = kvmalloc_array(nsops, sizeof(*sops), GFP_KERNEL_ACCOUNT); + sops = kvmalloc_array(nsops, sizeof(*sops), GFP_KERNEL); if (sops == NULL) return -ENOMEM; } -- 2.25.1