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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 01EFCC4363D for ; Wed, 7 Oct 2020 12:43:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9EBFA207EA for ; Wed, 7 Oct 2020 12:43:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728039AbgJGMnc (ORCPT ); Wed, 7 Oct 2020 08:43:32 -0400 Received: from icebox.esperi.org.uk ([81.187.191.129]:52288 "EHLO mail.esperi.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727927AbgJGMnb (ORCPT ); Wed, 7 Oct 2020 08:43:31 -0400 Received: from loom (nix@sidle.srvr.nix [192.168.14.8]) by mail.esperi.org.uk (8.16.1/8.16.1) with ESMTP id 097ChQrw024233; Wed, 7 Oct 2020 13:43:26 +0100 From: Nix To: Eric Wheeler Cc: Kai Krakow , linux-bcache@vger.kernel.org, linux-block@vger.kernel.org Subject: Re: [PATCH 1/3] bcache: introduce bcache sysfs entries for ioprio-based bypass/writeback hints References: <20201003111056.14635-1-kai@kaishome.de> <20201003111056.14635-2-kai@kaishome.de> <87362ucen3.fsf@esperi.org.uk> <87o8lfa692.fsf@esperi.org.uk> <87imbn9uud.fsf@esperi.org.uk> Emacs: you'll understand when you're older, dear. Date: Wed, 07 Oct 2020 13:43:26 +0100 In-Reply-To: (Eric Wheeler's message of "Wed, 7 Oct 2020 00:41:59 +0000 (UTC)") Message-ID: <87362q9pg1.fsf@esperi.org.uk> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.3.50 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-DCC--Metrics: loom 1102; Body=4 Fuz1=4 Fuz2=4 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 7 Oct 2020, Eric Wheeler said: > I always make my own cgroups with cgcreate, cgset, and cgexec. We're > using centos7 which is all systemd and I've never had a problem: Oh, maybe I'm panicking about nothing as usual then. Maybe this is all ancient systemd bugs that were fixed roughly when the Americas split off from Europe but which I've been worrying over without retesting ever since. :) > Something (hypothetically) like this: > cgcreate -g blkio:/my_bcache_settings > cgset -r blkio.bcache.bypass='read,write' my_bcache_settings > cgset -r blkio.bcache.writeback='write,meta' my_bcache_settings > > Then all you need to do is run this which isn't all that different from an > ionice invocation: > cgexec -g blkio:my_bcache_settings /usr/local/bin/some-program ... if it's that easy, I have no objections :) actually that looks significantly more expressive than what we have now. -- NULL && (void)