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[209.132.180.67]) by mx.google.com with ESMTP id n3-v6si20755902plb.185.2018.09.11.16.52.09; Tue, 11 Sep 2018 16:52:23 -0700 (PDT) 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=KgH3HA9u; 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 S1728220AbeILExc (ORCPT + 99 others); Wed, 12 Sep 2018 00:53:32 -0400 Received: from mail-yb1-f196.google.com ([209.85.219.196]:42942 "EHLO mail-yb1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725936AbeILExc (ORCPT ); Wed, 12 Sep 2018 00:53:32 -0400 Received: by mail-yb1-f196.google.com with SMTP id j8-v6so51498ybg.9; Tue, 11 Sep 2018 16:51:53 -0700 (PDT) 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=0rCgQO6XgVZi1lpxhVm/fJTejrvktbRjuN4qfvXFmE8=; b=KgH3HA9uLhe3ncZ8+5SZsBNQ2wsOOVyiPczLdlZrTEXRPHf4MIo0MHmd/8r46F6l0h GALy4DIRIkt+Fo3aj/yXMK+Hz/ZhZeX41Ue1eW2cDPfOO56221tHQ+Gzcpv7/zbvz+zz BuKpEoKA401kJNliLsVNszgpTumHJ/1JkB+IvAmetq1MPAtFGRi5ji24daYVmMo9SVBt wpUzN4SDvNN3qSPh+nmJE3veuWOUDovR0L5k26EdJGIqCMf7w4s+hK6XYdwJHy9fBBXk BhRs9rftICDTIEC/QXO83TXBxURUgTCUCHfRhBJ0CjFy7aNN47XEysIHj42BLzE8e0Za WkjA== 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=0rCgQO6XgVZi1lpxhVm/fJTejrvktbRjuN4qfvXFmE8=; b=PS1ct00cBLgOeY4hsbBWLrWVYFS46Pe36P8n+dpJG6svYWz/dow5t39Npc3Uzm2v4k fZDfEomCB4m74dJXMUeT0qik1Ravvm7VhthJ3c9J8N/twPJZ4K/20bYR0SZNQPk1FDvA boarg6tSKcL+gAopmF7nujfhBQu0xZ2tv60kNJc/yyogocyDlPdEwqOIqUEXeR2HQIOl sSxRIjTcVXWE0qHtUIMTDftB4ifH9yTOVjcamPR0KAOWsxod4GXSGDUjrTwJien6qAVw nvkKRu/9fbkURkzFnLYIDnrXjMM8JIrTEPN1zTLAGGVCIDCVZNg+uGvEosRxNxDWjPJc GLkg== X-Gm-Message-State: APzg51CSQrzv5Oz9rh2cRo/r5OCR8GoJydYHAuaArAukw+ZQWF7tOgfj OxhGC3VvWe0SUjUcknYc31M= X-Received: by 2002:a81:7852:: with SMTP id t79-v6mr13813666ywc.329.1536709912991; Tue, 11 Sep 2018 16:51:52 -0700 (PDT) Received: from localhost ([2620:10d:c091:200::1:6304]) by smtp.gmail.com with ESMTPSA id z193-v6sm7705397ywd.90.2018.09.11.16.51.51 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 11 Sep 2018 16:51:52 -0700 (PDT) Date: Tue, 11 Sep 2018 16:51:50 -0700 From: Tejun Heo To: Dennis Zhou Cc: Jens Axboe , Johannes Weiner , Josef Bacik , kernel-team@fb.com, linux-block@vger.kernel.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 09/12] blkcg: remove additional reference to the css Message-ID: <20180911235150.GD2966370@devbig004.ftw2.facebook.com> References: <20180911184137.35897-1-dennisszhou@gmail.com> <20180911184137.35897-10-dennisszhou@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180911184137.35897-10-dennisszhou@gmail.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 Tue, Sep 11, 2018 at 02:41:34PM -0400, Dennis Zhou wrote: > From: "Dennis Zhou (Facebook)" > > The previous patch in this series removed carrying around a pointer to > the css in blkg. However, the blkg association logic still relied on > taking a reference on the css to ensure we wouldn't fail in getting a > reference for the blkg. > > Here the implicit dependency on the css is removed. The association > continues to rely on the tryget logic walking up the blkg tree. This > streamlines the three ways that association can happen: normal, swap, > and writeback. > > Signed-off-by: Dennis Zhou Acked-by: Tejun Heo Thanks. -- tejun