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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id BFD3CC433F5 for ; Thu, 14 Apr 2022 09:09:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:From:References:Cc:To: Subject:MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=gZGNmlnO9pdUUyzufJhf0BC+weTG08QprAKmPqddM9I=; b=hpWXkQeMhoFOKx HnMJtOn8NsO7uf38ZThBsCTL50GjAnptutUISDrlfxNCMx7hIdCAA+br85kvJoQI8Vz2+kaWp6HHx oKRO0mbJkxZwbCyQWge3MyXlrZC7NJ/ft6sisjaqiksQz26Iop89cw/LUgZ2iH/PbXKQ890mU1qOQ A7H6e4H5NE+ISWX+S4GD9QojYgy9X58zY6zArIvoM8dUpu809XwS9E5Z/iBMyOO7s7BteuGLYTAnI h0l9Q82hbuElHa5scgPAFEma89T5+THeJgvPcTCnCvsJZMi0GN368O1B7zWGhCjDniTcNuwkRgv6k kz0ZKo7OYYogGGnx3BMw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nevS9-004liW-2S; Thu, 14 Apr 2022 09:07:49 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nevNX-004jkj-KG; Thu, 14 Apr 2022 09:03:05 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 68D0E139F; Thu, 14 Apr 2022 02:02:58 -0700 (PDT) Received: from [192.168.178.6] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 953713F5A1; Thu, 14 Apr 2022 02:02:55 -0700 (PDT) Message-ID: Date: Thu, 14 Apr 2022 11:02:36 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.5.0 Subject: Re: [PATCH 1/1] [PATCH v2]sched/pelt: Refine the enqueue_load_avg calculate method Content-Language: en-US To: Kuyo Chang , Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Steven Rostedt , Ben Segall , Mel Gorman , Daniel Bristot de Oliveira , Matthias Brugger Cc: wsd_upstream@mediatek.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org References: <20220414015940.9537-1-kuyo.chang@mediatek.com> From: Dietmar Eggemann In-Reply-To: <20220414015940.9537-1-kuyo.chang@mediatek.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220414_020303_763153_A963C41E X-CRM114-Status: GOOD ( 12.11 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 14/04/2022 03:59, Kuyo Chang wrote: > From: kuyo chang [...] > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > index d4bd299d67ab..159274482c4e 100644 > --- a/kernel/sched/fair.c > +++ b/kernel/sched/fair.c > @@ -3829,10 +3829,12 @@ static void attach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *s > > se->avg.runnable_sum = se->avg.runnable_avg * divider; > > - se->avg.load_sum = divider; > - if (se_weight(se)) { > + se->avg.load_sum = se->avg.load_avg * divider; > + if (se_weight(se) < se->avg.load_sum) { > se->avg.load_sum = > - div_u64(se->avg.load_avg * se->avg.load_sum, se_weight(se)); > + div_u64(se->avg.load_sum, se_weight(se)); Seems that this will fit on one line now. No braces needed then. > + } else { > + se->avg.load_sum = 1; > } > > enqueue_load_avg(cfs_rq, se); Looks like taskgroups are not affected since they get always online with cpu.shares/weight = 1024 (cgroup v1): cpu_cgroup_css_online() -> online_fair_sched_group() -> attach_entity_cfs_rq() -> attach_entity_load_avg() And reweight_entity() does not have this issue. Tested with `qemu-system-x86_64 ... cores=64 ... -enable-kvm` and weight=88761 for nice=0 tasks plus forcing se->avg.load_avg = 1 before the div_u64() in attach_entity_load_avg(). Tested-by: Dietmar Eggemann _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel