Received: by 2002:a05:6a11:4021:0:0:0:0 with SMTP id ky33csp2502495pxb; Tue, 21 Sep 2021 00:57:04 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzj1KSZY/Ose2Zvn0/wf2QcIIX15BzEkSfbfZtd2dCodwEqjSOORCsRcdg19pswxsrKQklD X-Received: by 2002:a17:906:3b96:: with SMTP id u22mr32580190ejf.370.1632211024392; Tue, 21 Sep 2021 00:57:04 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1632211024; cv=none; d=google.com; s=arc-20160816; b=hBawVBMeYiAUgn+qq4bX59l8mJZ9AyXc4rU0ih0GXssfEH9H5NyhBtOsqdPfAKXoF/ vYmHlV0jUD4JG20OvxSbJH2cfOM1iBgzTANh7SdJv+J/6AqNG72CJ9IRgvwwGyaOvBTl 8guzCKt6jvO2lOBYMt3ahojYpjzBew5eDEOzFTp61c7dUweRjfPztmMy5dTQQ+YLrtsb rKd/2NrARFjAAbxOQQ7TQTuQChXVwNRTmDwd9FtuU5R2RXHl9Pg84VV3jtdW7JNnG93g ckHDYgmbxmyM/bfEJcnts+7Q8iSTKXPNpfscO3yipBEAUfHuG4AW5WQmRpTUmnH126Sx HFUA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:user-agent:in-reply-to:content-disposition :mime-version:references:message-id:subject:cc:to:from:date; bh=q9sCfcJqN8tR70OVyhXuYDauI9fy6rQsJNMFp6KoAZs=; b=ER/16K4eQ/ovQVrBsB0KSFbaTAyYTdhacY+ac0ySqIC7ehJKQxKAfFb2vdPKK8+VSK 6nWhrF9UXmxLnVQx4MiK0+j577uzkh5ksFZq/Fia+JWnN+UdYs1P4roNqLt3EambgsrF 7Ij+u2ddCjvjRODEKyKXnZONIdMnJrYu+6YBSQ8w/BTb8srZbfOKT4uBcteIdDKdA4ZL 35E8vcW6CcNOkIrquuW/ReeRks6X234nfKhz4+wim7mWb5E5xl6pJPuHMmulEdagSB1i HXzM6aLeAfjDNbsAetgW87oNpN7mm6g2CnrHAT9t7NzQfO5dPA1F4wMjUXPOywVaUjrr vtww== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id qb27si6169772ejc.640.2021.09.21.00.56.40; Tue, 21 Sep 2021 00:57:04 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230456AbhIUHyk (ORCPT + 99 others); Tue, 21 Sep 2021 03:54:40 -0400 Received: from outbound-smtp10.blacknight.com ([46.22.139.15]:48465 "EHLO outbound-smtp10.blacknight.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230437AbhIUHyk (ORCPT ); Tue, 21 Sep 2021 03:54:40 -0400 Received: from mail.blacknight.com (pemlinmail05.blacknight.ie [81.17.254.26]) by outbound-smtp10.blacknight.com (Postfix) with ESMTPS id 4BB1B1C4B53 for ; Tue, 21 Sep 2021 08:53:11 +0100 (IST) Received: (qmail 17839 invoked from network); 21 Sep 2021 07:53:11 -0000 Received: from unknown (HELO techsingularity.net) (mgorman@techsingularity.net@[84.203.17.29]) by 81.17.254.9 with ESMTPSA (AES256-SHA encrypted, authenticated); 21 Sep 2021 07:53:11 -0000 Date: Tue, 21 Sep 2021 08:53:09 +0100 From: Mel Gorman To: Vincent Guittot Cc: Peter Zijlstra , Ingo Molnar , Valentin Schneider , Aubrey Li , Barry Song , Srikar Dronamraju , LKML Subject: Re: [PATCH 1/2] sched/fair: Remove redundant lookup of rq in check_preempt_wakeup Message-ID: <20210921075309.GK3959@techsingularity.net> References: <20210920142614.4891-1-mgorman@techsingularity.net> <20210920142614.4891-2-mgorman@techsingularity.net> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 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 Tue, Sep 21, 2021 at 09:21:16AM +0200, Vincent Guittot wrote: > On Mon, 20 Sept 2021 at 16:26, Mel Gorman wrote: > > > > The rq for curr is read during the function preamble, remove the > > redundant lookup. > > > > Signed-off-by: Mel Gorman > > --- > > kernel/sched/fair.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > > index ff69f245b939..038edfaaae9e 100644 > > --- a/kernel/sched/fair.c > > +++ b/kernel/sched/fair.c > > @@ -7190,7 +7190,7 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_ > > if (cse_is_idle != pse_is_idle) > > return; > > > > - update_curr(cfs_rq_of(se)); > > + update_curr(cfs_rq); > > se can have been modified by find_matching_se(&se, &pse) > I still expected the cfs_rq to be the same, particularly given that the context is about preempting the current task on a runqueue. Is that wrong? -- Mel Gorman SUSE Labs