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 B0657C00140 for ; Mon, 15 Aug 2022 13:23:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243043AbiHONXt (ORCPT ); Mon, 15 Aug 2022 09:23:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36670 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231941AbiHONXj (ORCPT ); Mon, 15 Aug 2022 09:23:39 -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 4DA701EEF4; Mon, 15 Aug 2022 06:23:34 -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 83E8D20B30; Mon, 15 Aug 2022 13:23:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1660569812; 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=fFv09Z66+Z9RxDrPyMXwvJHVM1uCWbRmOhnW660hzr8=; b=OqWPme3xuINwEeKBN52NXE/mRAnqhga05GZ3BOi4GLrd0F7tILAEBTFWeoaS5WpMm6U+b+ 99RNE/4Qgco/1FgCOblmw6w72VMGekSH328mCz2Y/HUt2vT9VlPdp0Ao+3RgrpKlVxMDnY gZBftxajDbblyzNmxcKMRxps1F0Fs0Y= 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 2917F13A93; Mon, 15 Aug 2022 13:23:32 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id LprDCNRI+mJuRAAAMHmgww (envelope-from ); Mon, 15 Aug 2022 13:23:32 +0000 Date: Mon, 15 Aug 2022 15:23:30 +0200 From: Michal =?iso-8859-1?Q?Koutn=FD?= To: Chengming Zhou Cc: hannes@cmpxchg.org, tj@kernel.org, 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: <20220815132330.GA24237@blackbody.suse.cz> References: <20220808110341.15799-1-zhouchengming@bytedance.com> <20220808110341.15799-10-zhouchengming@bytedance.com> <5ce118b3-bf3b-d9a4-004c-a5a355984b0f@bytedance.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5ce118b3-bf3b-d9a4-004c-a5a355984b0f@bytedance.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Aug 12, 2022 at 08:36:17PM +0800, Chengming Zhou wrote: > Could you help take a look if there is anything to improve? Thanks, just a little nit. > + The reason this control attribute exists is that PSI accounts stalls for > + each cgroup separately and aggregates it at each level of the hierarchy. > + This may cause non-negligible overhead for some workloads when under > + deep level of the hierarchy, in which case this control attribute can > + be used to disable PSI accounting in the cgroups. s/in the cgroups/in the non-leaf cgroups/ or s/in the cgroups/in the uninteresting cgroups/ (I'm concerned that it may result in lots of disabling if you want the performance. I'll expand on it in 2nd subthread.) Michal