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 X-Spam-Level: X-Spam-Status: No, score=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 79519C4CEC9 for ; Wed, 18 Sep 2019 15:19:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4A2BE21927 for ; Wed, 18 Sep 2019 15:19:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568819995; bh=x8WP2oP4JlgEfTy9voeEBqyi5z/eoUfmFxXzC2apt5M=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=Gu0SNM1nknER4tfq4QEuVaPyee3Z7WmRxCeWx1tsY4JSMQZd8fepGOfo3VU9z+n9e T7Wg1N1XZPH0ApWjVpkOI4lEbRZm6jZD2Ui0qechlmYkq47n9KVHdy5/hXZ3g4t4mX xMRjV94FXa3eL/lQo4KyYycBU5MwtuK9+qu1xG/U= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727056AbfIRPTy (ORCPT ); Wed, 18 Sep 2019 11:19:54 -0400 Received: from mail-qt1-f195.google.com ([209.85.160.195]:39328 "EHLO mail-qt1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726618AbfIRPTy (ORCPT ); Wed, 18 Sep 2019 11:19:54 -0400 Received: by mail-qt1-f195.google.com with SMTP id n7so186084qtb.6; Wed, 18 Sep 2019 08:19:53 -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=4/ozkoPe7I7HBcRNmLxlm9zJ7nl+dZfk4PcCpSwHEE0=; b=T2V++haNtE/r+StT15PyzM8Pcx6eaP5oSwCQUlyICnkOO9OKmWUetxLSpJ+zeMMVm4 Umui41NlalpMH08oCwjhUB8rcPoPnvb4O75FaSLSpzXsOC8AeDcEFpcwKgGoIrv8svQG Rq6lvlestuw80aSnQEx6Bp8hEcJzMpt1xbUH732DypsleAg7F1jnT0gy2aTwuAuVwG5i vG3D/JY8NyPMDOrlPAk9MoiOF/4w7Er3TI3dDYvtUxWooplJYAbrWZwmnWkbKkv2kZNJ O9knfGLSvhfjDSDSr3jLBMun+UVHVSZO/V4bM/o9XlBnZMKtacHwgn6vG8Zd4liINg+A vcKg== 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=4/ozkoPe7I7HBcRNmLxlm9zJ7nl+dZfk4PcCpSwHEE0=; b=HNj2Q43hlOubWboB/7iSXpUwuSUiU7YnnqcmaM4WzJrrPnmRKHdcgshnDCOx+zIJNQ G64B9BcvWfifDNBE/VIBMCxX6AoPDoQBWLzFTNZIYWjxj4lq2Q+qRUWrWYLHqs56m2Rc lRFK5yID/n3mhs9loBft6aNDuiSbCDCpi2E0P9VTQpB2/b9pkWkt6RD7jMCzIAZWeqFz uFaLNOWORb1dOAjlt8WuT2lfqu5FaJ7Rt0IG5Oyq1KI+1uB7CVUHxF+dkO3iwycltt8M sly5hzRww5QQW+EjDg301xc3QxpDmyMV37hfMyqfIy5cZ40pSG4WsHS7e7T6cztyjlJZ jVtA== X-Gm-Message-State: APjAAAUDZdbQr+2ce++dwJeJIWfSpSTkqIlX2H4pZzHL6cD9xBAmL8t/ tmSk6vJB95k1mymHiiHkkHw= X-Google-Smtp-Source: APXvYqyUV3Moh52SBY0W8pItsBoyuN8/Tuoat2VePzXuwr1j0fiDdwfUdmD7qbDpiunmtNeODAgw2w== X-Received: by 2002:ad4:43c5:: with SMTP id o5mr3692951qvs.207.1568819992834; Wed, 18 Sep 2019 08:19:52 -0700 (PDT) Received: from localhost ([2620:10d:c091:480::fef0]) by smtp.gmail.com with ESMTPSA id e6sm340551qtr.25.2019.09.18.08.19.51 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 18 Sep 2019 08:19:51 -0700 (PDT) Date: Wed, 18 Sep 2019 08:19:48 -0700 From: Tejun Heo To: Paolo Valente Cc: Jens Axboe , linux-block , linux-kernel@vger.kernel.org, ulf.hansson@linaro.org, linus.walleij@linaro.org, bfq-iosched@googlegroups.com, oleksandr@natalenko.name, cgroups@vger.kernel.org, Angelo Ruocco Subject: Re: [PATCH 2/2] block, bfq: delete "bfq" prefix from cgroup filenames Message-ID: <20190918151948.GL3084169@devbig004.ftw2.facebook.com> References: <20190917165148.19146-1-paolo.valente@linaro.org> <20190917165148.19146-3-paolo.valente@linaro.org> <20190917213209.GK3084169@devbig004.ftw2.facebook.com> <4D39D2FA-A487-4FAD-A67E-B90750CE0BD4@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4D39D2FA-A487-4FAD-A67E-B90750CE0BD4@linaro.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Hello, On Wed, Sep 18, 2019 at 07:18:50AM +0200, Paolo Valente wrote: > A solution that both fulfills userspace request and doesn't break > anything for hypothetical users of the current interface already made > it to mainline, and Linus liked it too. It is: Linus didn't like it. The implementation was a bit nasty. That was why it became a subject in the first place. > 19e9da9e86c4 ("block, bfq: add weight symlink to the bfq.weight cgroup parameter") > > But it was then reverted on Tejun's request to do exactly what we > don't want do any longer now: > cf8929885de3 ("cgroup/bfq: revert bfq.weight symlink change") Note that the interface was wrong at the time too. > So, Jens, Tejun, can we please just revert that revert? I think presenting both io.weight and io.bfq.weight interfaces are probably the best course of action at this point but why does it have to be a symlink? What's wrong with just creating another file with the same backing function? Thanks. -- tejun