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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A7AC3C32772 for ; Tue, 23 Aug 2022 18:10:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231787AbiHWSKy (ORCPT ); Tue, 23 Aug 2022 14:10:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54420 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233725AbiHWSK2 (ORCPT ); Tue, 23 Aug 2022 14:10:28 -0400 Received: from mail-pg1-x536.google.com (mail-pg1-x536.google.com [IPv6:2607:f8b0:4864:20::536]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8E3A3659D7; Tue, 23 Aug 2022 09:20:23 -0700 (PDT) Received: by mail-pg1-x536.google.com with SMTP id l64so12729008pge.0; Tue, 23 Aug 2022 09:20:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:from:to:cc; bh=MkchlG+vC7eeExntyPywB6o/N2CwihE3Mv9oTg/XCfA=; b=XxzpYtA2pnvxm7jj/aZsB1ovGYgGFFOxiJHjtvxhSaQ2REDVDoCQIjB/GtHH3oVwse NbSR71cHM3UNRFgLwyej9TpI0L9rWYkF3KkrxZ2C2kw/EhuAh1C8pna4IXsnCDF3BF2V 8IhM33IU1xrqLpTtcYD8/GGzjVMCaXX2XEfzTFIJp+wjFzbfTmxY37Dv4svHZMG0+KEo aRjhTxwWgpoysJLCODS4LSRitnpLJHVgILVZtGtASuPTh6vMwSzxhp5+JZNm5nJ5IYCo b3Dy8XSRPGHhnsPawF9cGPvUjeBwgKkMqHXYvYuy4cvIN6PNJjDppSYfrn2gz9H3zm6h 9Uyg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:x-gm-message-state:from:to:cc; bh=MkchlG+vC7eeExntyPywB6o/N2CwihE3Mv9oTg/XCfA=; b=EpQxwuYkO6H1Ov9BejHnLRtDiWaXH08YPEf6DEYt4Ihc8mGCkn9iFPQXw7IuqMiTE+ 53TC+bwoqqS47kWfDYoqMi5eiNdgtk+V6aHVqNBgsL1MSBIuXkSkqmTjqHV2IihCw8oV hSnWFQXZlvldnUHwBes4VOGj/1xE0oJ4okmeyqSwOSPOypAOzhvlG+40Rk0824YmvyHl 1MkQQ/kkRz/HkhQ1LTocje5+ZlhrNMecQpxa/9afJWrfdFCpCD/j4Ex76zvR6gclroeP pqvctdpSM2hzu9+wQvaZQhRwp+yoUrCmPoq0tbxiE7EJXzoyemT3CShB6xFujyDbzaWB ensA== X-Gm-Message-State: ACgBeo10+z7Ke1MtBXU9L1W+sD371L/6+5ho6rt5ziK2UKRW1fMWezOS rROXm3g+bW+Hu3D7ojQnZGU= X-Google-Smtp-Source: AA6agR4cW34xCWONe1DFQhmDIqb/ilOQuYVa7OvNWr8Tj8a5MCNIZ+ylQxDsXgma0bv+PadMQYQ2jA== X-Received: by 2002:a63:131c:0:b0:427:7f15:470f with SMTP id i28-20020a63131c000000b004277f15470fmr21682374pgl.232.1661271622771; Tue, 23 Aug 2022 09:20:22 -0700 (PDT) Received: from localhost (2603-800c-1a02-1bae-a7fa-157f-969a-4cde.res6.spectrum.com. [2603:800c:1a02:1bae:a7fa:157f:969a:4cde]) by smtp.gmail.com with ESMTPSA id d135-20020a621d8d000000b0052d4b0d0c74sm11029697pfd.70.2022.08.23.09.20.21 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 23 Aug 2022 09:20:22 -0700 (PDT) Sender: Tejun Heo Date: Tue, 23 Aug 2022 06:20:20 -1000 From: Tejun Heo To: Johannes Weiner Cc: Chengming Zhou , Michal =?iso-8859-1?Q?Koutn=FD?= , corbet@lwn.net, surenb@google.com, mingo@redhat.com, peterz@infradead.org, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, cgroups@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, songmuchun@bytedance.com Subject: Re: [PATCH v2 09/10] sched/psi: per-cgroup PSI stats disable/re-enable interface Message-ID: References: <20220808110341.15799-1-zhouchengming@bytedance.com> <20220808110341.15799-10-zhouchengming@bytedance.com> <20220815132343.GA22640@blackbody.suse.cz> <9d1997a4-9278-07bd-7f57-952306b28b14@bytedance.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On Tue, Aug 23, 2022 at 11:35:59AM -0400, Johannes Weiner wrote: > Re 1: I agree. If desired in the future we can make the default > configurable. Kconfig, mount option, what have you. cgroup.pressure > will work fine as a name regardless of what the default is. Given that there's already cgroup_disable=pressure for cases which want it fully disabled, I'm not sure we'd need to add more complex disabling options. The only difference that'd make is for users who are configuring cgroups manually which is pretty rare and it'd create a clear downside of increasing confusion as the base assumption becomes dynamic. So, I think the current default-on with opting-out is and will be just fine. > Re 2: Not all consumers of the pressure metrics create trigger. I > would argue that few do. So it isn't the best signal to decide on > whether aggregation should occur. And yes, it's further complicated by > the triggers being written to the very pressure files. If we don't > hide them, we have to come up with another way to mark them as stale, > lest they confuse the heck out of users. Without breaking format... > > So IMO, default-enable, "cgroup.pressure" as a name, and hiding the > pressure files should be good for now while allowing to make the > default configurable down the line. Sounds great. Thanks. -- tejun