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=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 2F010C433B4 for ; Wed, 12 May 2021 09:37:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DF3F261184 for ; Wed, 12 May 2021 09:37:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230218AbhELJi3 (ORCPT ); Wed, 12 May 2021 05:38:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52804 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230019AbhELJi2 (ORCPT ); Wed, 12 May 2021 05:38:28 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AC041C061574 for ; Wed, 12 May 2021 02:37:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.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=dXnrQikcCfOUvytGhAWySk6PCwU4Gt2ixLQp3WDf4AQ=; b=DSa92xT9ZL1WeODw4HG0VkoHN4 x21MTl71QWsdRfG5umBGK1jbQeEfyH0i6v8KYdXR1kKipprtrjCMqc6lVlnNuKbmdgn8z5x+uGK7p 3F+Tx0BTkseH4dGMLVL3BwIgSIWWq8s7/7yD+RB+gj5xN1Wpz6BIb6WMNQz0fCsY0rcq1Ewq9Ulk/ sUyV2KsvaoI+PCphqGvci/AhqjswmV1SR6naoe4Pc7HUwlCGPeTXfgZSyv8FP0ykVA5WR+x7qnqjf pjFPsliiHCmLo6VGChLkpKoFOz869Je5v8eiIE8VpEkL6LkTGt7JhS0Vr4vPQ9TLkQvdN51saBSOs eXIZaX6A==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94 #2 (Red Hat Linux)) id 1lglCV-0088bR-EN; Wed, 12 May 2021 09:32:31 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id BFBA13002C1; Wed, 12 May 2021 11:30:42 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id AC35B2B86E5EC; Wed, 12 May 2021 11:30:42 +0200 (CEST) Date: Wed, 12 May 2021 11:30:42 +0200 From: Peter Zijlstra To: "Gautham R. Shenoy" Cc: Mel Gorman , Ingo Molnar , Vincent Guittot , Srikar Dronamraju , linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] sched/fair: Fix clearing of has_idle_cores flag Message-ID: References: <1620746169-13996-1-git-send-email-ego@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1620746169-13996-1-git-send-email-ego@linux.vnet.ibm.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 11, 2021 at 08:46:09PM +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()") > Acked-by: Mel Gorman > Reviewed-by: Vincent Guittot > Reviewed-by: Srikar Dronamraju > Signed-off-by: Gautham R. Shenoy Thanks!