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[209.132.180.67]) by mx.google.com with ESMTP id k33si12099934pld.374.2018.12.03.08.19.42; Mon, 03 Dec 2018 08:20:15 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=fail header.i=@gmail.com header.s=20161025 header.b=FK6aIGGX; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726805AbeLCQRT (ORCPT + 99 others); Mon, 3 Dec 2018 11:17:19 -0500 Received: from mail-yw1-f47.google.com ([209.85.161.47]:38116 "EHLO mail-yw1-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726586AbeLCQRS (ORCPT ); Mon, 3 Dec 2018 11:17:18 -0500 Received: by mail-yw1-f47.google.com with SMTP id i20so5609869ywc.5; Mon, 03 Dec 2018 08:17:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=Y9j3PhmycYw6Qr1C9EO/9ht1q/JW9XQqu6X+2fdt+eE=; b=FK6aIGGXfd4GzHu+5VcLQc17PnjRnWyavIN+cclCpGigX1eY04H3IaHixevNcYdrIV CbaUQEVfobLySM5+4jHCAJABP26EZ1mAxFk3Gb1geQlOQt38QDRK2dsMPJysPzrNQGL3 OylTo833d5NjdRqThEQ2H3Spg2CJXKUoJvrnFusBN5pvw5kqpWvRAw/0FhNl5/8UUFSI e8rI87deBXkjFMm34nUakxXZXvpylsw6gPlJmSNOd3+9hwf3wfekA+HnOs5aiQ4xQ2I6 7A0O7gHBosNewqjcTCBIKF0/kP9e0rKpr3jgDS4G+MjG6KHdzj2CxHqf0O6e+NXQHK+F HQVw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to:user-agent; bh=Y9j3PhmycYw6Qr1C9EO/9ht1q/JW9XQqu6X+2fdt+eE=; b=iYHb/Aaqjj57KrwBZj/wbAvuFyE27to0EVU3uKm8wTdcV6srGExBmtHj6EKje9+deB XUhytdSDYzx2SoqoMVoxbA1Yv5rqpneOVdtn4oP8vVYcahrx/UyyPJXpv+Hv7k7KUgV/ 1qLmBust+5Gy8h4i4LoAwtuVGr0NM+Lm72WulwQcLURanB/lA69+NVDvDkWzK5sScbHK ovh80tBjahkVebSCkRks+LCkUDXoqM9W7ytWSXn3TY/zYGRCaelRQFrOC6NtjleDzTgc g5KegPe++2S/lKm/oGNU21KpRg5C1Vf52bv4NBN1+mROTPp7ZiKuhceWjvy78olGwBbY vr3g== X-Gm-Message-State: AA+aEWb4NySN2puskPLTnt3FDwrestVx3wtDk3ySaM/k6otYyVMC2+79 nCJ2Zll4vILOR+Czwz4MiAk= X-Received: by 2002:a81:4412:: with SMTP id r18mr16279713ywa.204.1543853828897; Mon, 03 Dec 2018 08:17:08 -0800 (PST) Received: from localhost ([2620:10d:c091:200::5:20d7]) by smtp.gmail.com with ESMTPSA id n16sm5936001ywn.31.2018.12.03.08.17.07 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 03 Dec 2018 08:17:08 -0800 (PST) Date: Mon, 3 Dec 2018 08:17:06 -0800 From: Tejun Heo To: Roman Gushchin Cc: Oleg Nesterov , Dan Carpenter , Mike Rapoport , cgroups@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@fb.com, Roman Gushchin Subject: Re: [PATCH v4 3/7] cgroup: protect cgroup->nr_(dying_)descendants by css_set_lock Message-ID: <20181203161706.GL2509588@devbig004.ftw2.facebook.com> References: <20181130234745.6756-1-guro@fb.com> <20181130234745.6756-4-guro@fb.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181130234745.6756-4-guro@fb.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Nov 30, 2018 at 03:47:41PM -0800, Roman Gushchin wrote: > + * nr_descendants and nr_dying_descendants are protected > + * by cgroup_mutex and css_set_lock. Can you be a bit more specific - hold both for writes, either for reads. Thanks. -- tejun