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=-10.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 D058AC433B4 for ; Tue, 27 Apr 2021 07:55:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 86D35613B3 for ; Tue, 27 Apr 2021 07:55:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234854AbhD0H41 (ORCPT ); Tue, 27 Apr 2021 03:56:27 -0400 Received: from outbound-smtp15.blacknight.com ([46.22.139.232]:45119 "EHLO outbound-smtp15.blacknight.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230348AbhD0H4Y (ORCPT ); Tue, 27 Apr 2021 03:56:24 -0400 Received: from mail.blacknight.com (pemlinmail05.blacknight.ie [81.17.254.26]) by outbound-smtp15.blacknight.com (Postfix) with ESMTPS id 622691C66F9 for ; Tue, 27 Apr 2021 08:55:40 +0100 (IST) Received: (qmail 809 invoked from network); 27 Apr 2021 07:55:40 -0000 Received: from unknown (HELO techsingularity.net) (mgorman@techsingularity.net@[84.203.17.248]) by 81.17.254.9 with ESMTPSA (AES256-SHA encrypted, authenticated); 27 Apr 2021 07:55:40 -0000 Date: Tue, 27 Apr 2021 08:55:38 +0100 From: Mel Gorman To: "Gautham R. Shenoy" Cc: "Peter Zijlstra (Intel)" , Ingo Molnar , Vincent Guittot , Srikar Dronamraju , linux-kernel@vger.kernel.org Subject: Re: [PATCH] sched/fair: Fix unsetting of "has_idle_cores" flag Message-ID: <20210427075538.GF4239@techsingularity.net> References: <1619456652-19143-1-git-send-email-ego@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <1619456652-19143-1-git-send-email-ego@linux.vnet.ibm.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Apr 26, 2021 at 10:34:12PM +0530, Gautham R. Shenoy wrote: > From: "Gautham R. Shenoy" > > In commit 9fe1f127b913 ("sched/fair: Merge select_idle_core/cpu()"), in > select_idle_cpu(), we check if an idle core is present in the LLC of the > target CPU via the flag "has_idle_cores". We look for the idle core in > select_idle_cores(). If select_idle_cores() isn't able to find an idle > core/CPU, we need to unset the has_idle_cores flag in the LLC of the > target to prevent other CPUs from going down this route. > > However, the current code is unsetting it in the LLC of the current CPU > instead of the target CPU. This patch fixes this issue. > > Fixes: Commit 9fe1f127b913 ("sched/fair: Merge select_idle_core/cpu()") > Cc: Mel Gorman > Signed-off-by: Gautham R. Shenoy Acked-by: Mel Gorman -- Mel Gorman SUSE Labs