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[23.128.96.18]) by mx.google.com with ESMTP id o2si804277edr.564.2021.09.12.09.09.30; Sun, 12 Sep 2021 09:09:55 -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=@google.com header.s=20210112 header.b=WGHGy2wT; 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=REJECT sp=REJECT dis=NONE) header.from=google.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230158AbhILQHL (ORCPT + 99 others); Sun, 12 Sep 2021 12:07:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56960 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229560AbhILQHK (ORCPT ); Sun, 12 Sep 2021 12:07:10 -0400 Received: from mail-lj1-x234.google.com (mail-lj1-x234.google.com [IPv6:2a00:1450:4864:20::234]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3291DC061574 for ; Sun, 12 Sep 2021 09:05:56 -0700 (PDT) Received: by mail-lj1-x234.google.com with SMTP id s12so12630926ljg.0 for ; Sun, 12 Sep 2021 09:05:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=08mAPjyxBKrJAINcSHI5DwIe03TZTttNNN61qA9Q5BI=; b=WGHGy2wTwEa24xnd0LxtlPuE1NdaZtAac70TQ59rf4FCpLXG4snXCOzj26Eq9wc+ZH UMZSXdGP4oVIKywhZS0qlnqoWJBgiq3kFoRaOnLu6yCW1OjYKGSYnKbq8CF6T09LUNzG bG5Qlt8g/l/0FRrCFdRHREY54BGmwMQhd+BDMp1cIDM+GZ32/dQsjKGpcpio31T6PtPl Mhdu/isuIxrUBMg3L5hMWxUo1lhPHjDP0xpe50er80KHRN5LL84pMoNlommMKYVl5N4/ mFPnJSR3HVCa8OgAe1tpUVSQ/hMCufYdKoMUNoopOXSCLZPaujn8u78vA5lM1tX7xh5e OkFg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=08mAPjyxBKrJAINcSHI5DwIe03TZTttNNN61qA9Q5BI=; b=ujvuZ5XUy1tuLA8OtOx8XHpM6oQLfhU9zz+aEsbUPlDyydxpvQAiXcP4z9i1bM5QQw EiF8JGinre/AaDte/lYe75XqPb3lyaZEOiQTWqBOuI+FHpRycoOI0zw38BCPcJgcGOkW 8kQcb7XV/myuCdvoT4TUJ4vp0xCcHAakw2D88sfr44JVq6/Al8X8qm0RGwtR09f4iyuz EGKzVVBTr0aELgukoaMD+7k7viPZgzAqrh3EMeJ/qR5k2StcI0OzMeMHIfEll2dVZUBG QOUYi3sWob1ZmnQKIlQfuHqHPD3wQBUIY5DDsfRq3a8APqu1iRzN2jjwxVziXMgEUW4W PkSA== X-Gm-Message-State: AOAM530qA8/4LZs5BqfQYt6PMMst57gSEwyfOZPNWptaBIrmoeLT+LcJ dFJXxh64LQRExx4Tcr4OnmxS+lOfJWWEoA24z+oQeA== X-Received: by 2002:a05:651c:385:: with SMTP id e5mr6436000ljp.35.1631462753264; Sun, 12 Sep 2021 09:05:53 -0700 (PDT) MIME-Version: 1.0 References: <90e254df-0dfe-f080-011e-b7c53ee7fd20@virtuozzo.com> In-Reply-To: <90e254df-0dfe-f080-011e-b7c53ee7fd20@virtuozzo.com> From: Shakeel Butt Date: Sun, 12 Sep 2021 09:05:41 -0700 Message-ID: Subject: Re: [PATCH] ipc: remove memcg accounting for sops objects in do_semtimedop() To: Vasily Averin Cc: Andrew Morton , Linus Torvalds , LKML , Michal Hocko , Johannes Weiner , kernel@openvz.org, Cgroups Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Sep 11, 2021 at 12:40 AM Vasily Averin wrote: > > 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 Thanks Vasily. Acked-by: Shakeel Butt