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=-8.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 62031C433E0 for ; Tue, 2 Mar 2021 10:29:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 15CEF6146D for ; Tue, 2 Mar 2021 10:29:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1380057AbhCBK0o (ORCPT ); Tue, 2 Mar 2021 05:26:44 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:19434 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1379456AbhCBKFj (ORCPT ); Tue, 2 Mar 2021 05:05:39 -0500 Received: from pps.filterd (m0098399.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 122A399m033891; Tue, 2 Mar 2021 05:04:33 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=date : from : to : cc : subject : message-id : reply-to : references : mime-version : content-type : in-reply-to; s=pp1; bh=xG1Q8xntkpqsWLtw6mW1OsuOjgSQK4G5eydDJOFmknQ=; b=SSnKj/SeG60Ky5b9weB09w8e1R0K7K79fytS213G6GyBx7iMv4yarLI50zRHhicmfzX2 extVV965lVwz8fA4ZpfVmGmjWEjw8XOf4C3P9tpQd/cv2T1/gFIofFoq+WJfpn9gj0kR 3ef7QvlvlGqBliVR78bjgWFI2cxkazrU2Z/H9VZHtNRR/jnhkT3pYdGWQo4IBhYuYMCY DNGEAc1JcBCh1ihYj2CVzjYXcTXLdk/k2Mg5FXje72xYzUX6UyyZyzvTOjfjOVKKDOSN 8zjZzZ+5r4alcDmSmRS67bSsz93v4vShUEN249kk28QPAa58JU1irqFSpfescdAAk1NV Ug== Received: from ppma05fra.de.ibm.com (6c.4a.5195.ip4.static.sl-reverse.com [149.81.74.108]) by mx0a-001b2d01.pphosted.com with ESMTP id 371jtm93g4-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 02 Mar 2021 05:04:33 -0500 Received: from pps.filterd (ppma05fra.de.ibm.com [127.0.0.1]) by ppma05fra.de.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 122A2mrk000544; Tue, 2 Mar 2021 10:04:31 GMT Received: from b06cxnps3075.portsmouth.uk.ibm.com (d06relay10.portsmouth.uk.ibm.com [9.149.109.195]) by ppma05fra.de.ibm.com with ESMTP id 3712v50cfq-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 02 Mar 2021 10:04:30 +0000 Received: from d06av22.portsmouth.uk.ibm.com (d06av22.portsmouth.uk.ibm.com [9.149.105.58]) by b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 122A4S8d35783040 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 2 Mar 2021 10:04:28 GMT Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 999544C04E; Tue, 2 Mar 2021 10:04:28 +0000 (GMT) Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 5B7C14C05A; Tue, 2 Mar 2021 10:04:26 +0000 (GMT) Received: from linux.vnet.ibm.com (unknown [9.126.150.29]) by d06av22.portsmouth.uk.ibm.com (Postfix) with SMTP; Tue, 2 Mar 2021 10:04:26 +0000 (GMT) Date: Tue, 2 Mar 2021 15:34:25 +0530 From: Srikar Dronamraju To: Dietmar Eggemann Cc: Ingo Molnar , Peter Zijlstra , LKML , Mel Gorman , Rik van Riel , Thomas Gleixner , Valentin Schneider , Vincent Guittot , Michael Ellerman , Michael Neuling , Gautham R Shenoy , Parth Shah Subject: Re: [PATCH] sched/fair: Prefer idle CPU to cache affinity Message-ID: <20210302100425.GM2028034@linux.vnet.ibm.com> Reply-To: Srikar Dronamraju References: <20210226164029.122432-1-srikar@linux.vnet.ibm.com> <19bfd781-05f7-b220-d8a2-fde8ea2d9959@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <19bfd781-05f7-b220-d8a2-fde8ea2d9959@arm.com> X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.369,18.0.761 definitions=2021-03-02_03:2021-03-01,2021-03-02 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 adultscore=0 mlxlogscore=835 lowpriorityscore=0 clxscore=1015 priorityscore=1501 impostorscore=0 mlxscore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2103020082 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Dietmar Eggemann [2021-03-02 10:53:06]: > On 26/02/2021 17:40, Srikar Dronamraju wrote: > > [...] > > > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > > index 8a8bd7b13634..d49bfcdc4a19 100644 > > --- a/kernel/sched/fair.c > > +++ b/kernel/sched/fair.c > > @@ -5869,6 +5869,36 @@ wake_affine_weight(struct sched_domain *sd, struct task_struct *p, > > return this_eff_load < prev_eff_load ? this_cpu : nr_cpumask_bits; > > } > > > > +static int prefer_idler_llc(int this_cpu, int prev_cpu, int sync) > > +{ > > + struct sched_domain_shared *tsds, *psds; > > + int pnr_busy, pllc_size, tnr_busy, tllc_size, diff; > > + > > + tsds = rcu_dereference(per_cpu(sd_llc_shared, this_cpu)); > > + tnr_busy = atomic_read(&tsds->nr_busy_cpus); > > + tllc_size = per_cpu(sd_llc_size, this_cpu); > > + > > + psds = rcu_dereference(per_cpu(sd_llc_shared, prev_cpu)); > > + pnr_busy = atomic_read(&psds->nr_busy_cpus); > > + pllc_size = per_cpu(sd_llc_size, prev_cpu); > > + > > + /* No need to compare, if both LLCs are fully loaded */ > > + if (pnr_busy == pllc_size && tnr_busy == pllc_size) > > ^ > shouldn't this be tllc_size ? Yes, thanks for pointing out. -- Thanks and Regards Srikar Dronamraju