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 B463FC00140 for ; Mon, 15 Aug 2022 13:24:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232217AbiHONYI (ORCPT ); Mon, 15 Aug 2022 09:24:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36578 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243034AbiHONXs (ORCPT ); Mon, 15 Aug 2022 09:23:48 -0400 Received: from smtp-out2.suse.de (smtp-out2.suse.de [IPv6:2001:67c:2178:6::1d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CFC0C1DA70; Mon, 15 Aug 2022 06:23:46 -0700 (PDT) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 878E220B30; Mon, 15 Aug 2022 13:23:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1660569825; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=cHBCVrYF6PCd1Kfozii15caVkPvyJaqe6SVHf6nDFnY=; b=HMGy9EAP6+jcOvZN5k/wtqCrne3YQi9csqDNao8rsF5YSRTmZ6Rbab2gsZeg8D97ThDzG7 NRx6qqjBQnQbeJmU0EXssWO2uNV7EEYZgSn7oqQdR0U3BtsBS741D8Ye1k40KbKH+WIB1q uEg5kck5difRZBcHEtu/zIYOT0gZQuI= Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 3CC5C13A93; Mon, 15 Aug 2022 13:23:45 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id x9raDeFI+mKBRAAAMHmgww (envelope-from ); Mon, 15 Aug 2022 13:23:45 +0000 Date: Mon, 15 Aug 2022 15:23:43 +0200 From: Michal =?iso-8859-1?Q?Koutn=FD?= To: Johannes Weiner Cc: Chengming Zhou , Tejun Heo , 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: <20220815132343.GA22640@blackbody.suse.cz> References: <20220808110341.15799-1-zhouchengming@bytedance.com> <20220808110341.15799-10-zhouchengming@bytedance.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 10, 2022 at 11:25:07AM -0400, Johannes Weiner wrote: > cgroup.pressure.enable sounds good to me too. Or, because it's > default-enabled and that likely won't change, cgroup.pressure.disable. Will it not change? I'd say that user would be interested in particular level or even just level in subtree for PSI, so the opt-out may result in lots of explicit disablements (or even watch for cgroups created and disable PSI there) to get some performance back. I have two suggestions based on the above: 1) Make the default globally configurable (mount option?) 2) Allow implicit enablement upon trigger creation WDYT? Michal