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=-3.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 84994C433DF for ; Thu, 11 Jun 2020 14:28:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 563AC2072F for ; Thu, 11 Jun 2020 14:28:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="e/gtYKTO" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728306AbgFKO2j (ORCPT ); Thu, 11 Jun 2020 10:28:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59874 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726657AbgFKO2i (ORCPT ); Thu, 11 Jun 2020 10:28:38 -0400 Received: from merlin.infradead.org (unknown [IPv6:2001:8b0:10b:1231::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 10B5BC08C5C1 for ; Thu, 11 Jun 2020 07:28:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=veEoCUcIkaZEO/Qd1GN5y9WKpi7LCLgfeW+AZ30hNVY=; b=e/gtYKTOShBi8mkaJqoOURjwWJ XTpY03rSSHDfAFJDIr1YIAjHBh7FFYyKkhMdFQKdE8zoVMy6mEP3IrA0cf6OfR5Ru+wppavDi86ah lSmOo+tu4Lv97x7gYuFsIdFIScJDLhaztevDi6GOHrHHQ6KyEcQVvuQGOj0bMD3behSSZ6nRxhrqV mejQvXqSeOD+dtGGMtAo1m0TyniM8kJ1WyfvScQ3aVx5DBJAKdvSwSxBejcNDiaF3clQS2TRVtI8A HJoXxsNrX0A2Y9qgRLEe/M2rrFMIvUMbwn3+ECuszRtsayE9GtXeaVxxuOWQzBU8h14zMYN/9TqAQ IihkAxJg==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jjOBc-0002L0-1b; Thu, 11 Jun 2020 14:28:08 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 4D035301A7A; Thu, 11 Jun 2020 16:28:06 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 2B9F0220F9FA4; Thu, 11 Jun 2020 16:28:06 +0200 (CEST) Date: Thu, 11 Jun 2020 16:28:06 +0200 From: Peter Zijlstra To: Valentin Schneider Cc: Vincent Guittot , mingo@redhat.com, juri.lelli@redhat.com, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, linux-kernel@vger.kernel.org, iwtbavbm@gmail.com Subject: Re: [PATCH v2] sched/fair: fix nohz next idle balance Message-ID: <20200611142806.GJ2531@hirez.programming.kicks-ass.net> References: <20200609123748.18636-1-vincent.guittot@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 11, 2020 at 03:12:11PM +0100, Valentin Schneider wrote: > > On 09/06/20 13:37, Vincent Guittot wrote: > > With commit: > > 'b7031a02ec75 ("sched/fair: Add NOHZ_STATS_KICK")' > > rebalance_domains of the local cfs_rq happens before others idle cpus have > > updated nohz.next_balance and its value is overwritten. > > > > Move the update of nohz.next_balance for other idles cpus before balancing > > and updating the next_balance of local cfs_rq. > > > > Also, the nohz.next_balance is now updated only if all idle cpus got a > > chance to rebalance their domains and the idle balance has not been aborted > > because of new activities on the CPU. In case of need_resched, the idle > > load balance will be kick the next jiffie in order to address remaining > > ilb. > > > > Reported-by: Peng Liu > > Signed-off-by: Vincent Guittot > > FWIW: > Reviewed-by: Valentin Schneider > > Do we want a Fixes: tag for this? I'm thinking > b7031a02ec75 ("sched/fair: Add NOHZ_STATS_KICK") Done, thanks!