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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D0BDAC433FE for ; Sun, 13 Nov 2022 08:51:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235278AbiKMIv4 (ORCPT ); Sun, 13 Nov 2022 03:51:56 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48346 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235281AbiKMIvp (ORCPT ); Sun, 13 Nov 2022 03:51:45 -0500 Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B204E13D75 for ; Sun, 13 Nov 2022 00:51:42 -0800 (PST) Received: from pps.filterd (m0187473.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.17.1.19/8.17.1.5) with ESMTP id 2AD8nkjR039083; Sun, 13 Nov 2022 08:51:13 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=message-id : date : mime-version : subject : to : references : from : in-reply-to : content-type : content-transfer-encoding; s=pp1; bh=zYXKdQKcR2j7x8Ifo8hnkIpJpIWAo3z7o0zmDJdO57Y=; b=mdo9wdrwT6ezTQWFKDusQmx2WJUy6jmVKODmg3xRY8zE5WcODwXGVwea8jGlRNiifjpv rVxitgjsRxr+UGDNUaSItWA8Wpqjz2atAzpDBQvyOBhU/eQtUc9q1/mMmHO/5P2ev6yQ a4BPYR9VOHR4qPeEXYRbOIlfuqQYO+KebvgiHI+N+3G54fzjaK2trfMdz0SBBmDNzmxt 0WoM4ScIu/JZfI9a/tDHj8vIM1EO1j8CXFCybGHnvgZd21buUiIVU7rJbs3QEHfJX8fs t/gR58jlgQ2LqVPNmR3Kea1WcRRBH037HNaMMRKY1QGLxXqueylHSNPgHEwOA1jNIUIV 9w== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3ktwds00xe-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Sun, 13 Nov 2022 08:51:12 +0000 Received: from m0187473.ppops.net (m0187473.ppops.net [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 2AD8oVXv001507; Sun, 13 Nov 2022 08:51:12 GMT Received: from ppma03dal.us.ibm.com (b.bd.3ea9.ip4.static.sl-reverse.com [169.62.189.11]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3ktwds00uj-15 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Sun, 13 Nov 2022 08:51:12 +0000 Received: from pps.filterd (ppma03dal.us.ibm.com [127.0.0.1]) by ppma03dal.us.ibm.com (8.16.1.2/8.16.1.2) with SMTP id 2AD7pAC7013780; Sun, 13 Nov 2022 07:56:32 GMT Received: from b03cxnp07028.gho.boulder.ibm.com (b03cxnp07028.gho.boulder.ibm.com [9.17.130.15]) by ppma03dal.us.ibm.com with ESMTP id 3kt3498kqa-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Sun, 13 Nov 2022 07:56:32 +0000 Received: from smtpav02.dal12v.mail.ibm.com ([9.208.128.128]) by b03cxnp07028.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 2AD7uWsE21496372 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Sun, 13 Nov 2022 07:56:33 GMT Received: from smtpav02.dal12v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id EDAE05805A; Sun, 13 Nov 2022 07:56:30 +0000 (GMT) Received: from smtpav02.dal12v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 34C8158051; Sun, 13 Nov 2022 07:56:22 +0000 (GMT) Received: from [9.160.60.23] (unknown [9.160.60.23]) by smtpav02.dal12v.mail.ibm.com (Postfix) with ESMTP; Sun, 13 Nov 2022 07:56:21 +0000 (GMT) Message-ID: <34112324-de67-55eb-92bc-181a98c4311c@linux.vnet.ibm.com> Date: Sun, 13 Nov 2022 13:26:20 +0530 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.4.2 Subject: Re: [PATCH v7 0/9] Add latency priority for CFS class Content-Language: en-US To: Vincent Guittot References: <20221028093403.6673-1-vincent.guittot@linaro.org> From: shrikanth suresh hegde In-Reply-To: <20221028093403.6673-1-vincent.guittot@linaro.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: 2CDum0LG8NnAnEXZU0lbY_CFEhSiqxcK X-Proofpoint-GUID: uMDDQf1TnZepwe486maGytKiZkd28nPx X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.219,Aquarius:18.0.895,Hydra:6.0.545,FMLib:17.11.122.1 definitions=2022-11-13_05,2022-11-11_01,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 lowpriorityscore=0 malwarescore=0 spamscore=0 clxscore=1015 mlxscore=0 bulkscore=0 impostorscore=0 priorityscore=1501 phishscore=0 mlxlogscore=833 adultscore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2210170000 definitions=main-2211130054 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > This patchset restarts the work about adding a latency priority to describe > the latency tolerance of cfs tasks. > > Hi Vincent. Tested the patches on the power10 machine. It is 80 core system with SMT=8. i.e total of 640 cpus. on the large workload which mainly interacts with the database there is minor improvement of 3-5%. the method followed is creating a cgroup, assigning a latency nice value of -20, -10, 0 and adding the tasks to procs of the cgroup. outside of cgroup, stress-ng load is running and it is not set any latency value. stress-ng --cpu=768 -l 50 with microbenchmarks, hackbench the values are more or less the same. for large process pool of 60, there is 10% improvement. schbench tail latencies show significant improvement with low and medium load upto 256 groups. only 512 groups shows a slight decline. Hackbench (Iterations or N=50) Process 6.1_Base 6.1_Latency_Nice 10 0.13 0.14 20 0.18 0.18 30 0.24 0.25 40 0.34 0.33 50 0.40 0.41 60 0.53 0.49 schbench (Iterations or N=5) Groups: 1 6.1_Base 6.1_Latency_Nice 50.0th: 10.8 9.8 75.0th: 12.4 11.4 90.0th: 14.2 13.2 95.0th: 15.6 14.6 99.0th: 27.8 19.0 99.5th: 38.0 21.6 99.9th: 66.2 25.4 Groups: 2 6.1_Base 6.1_Latency_Nice 50.0th: 11.2 10.8 75.0th: 13.2 12.4 90.0th: 15.0 15.0 95.0th: 16.6 16.6 99.0th: 22.4 22.8 99.5th: 23.8 27.8 99.9th: 30.2 45.6 Groups: 4 6.1_Base 6.1_Latency_Nice 50.0th: 13.8 11.2 75.0th: 16.0 13.2 90.0th: 18.6 15.2 95.0th: 20.4 16.6 99.0th: 28.8 21.6 99.5th: 48.8 25.2 99.9th: 900.2 47.0 Groups: 8 6.1_Base 6.1_Latency_Nice 50.0th: 17.8 14.4 75.0th: 21.8 17.2 90.0th: 25.4 20.4 95.0th: 28.0 22.4 99.0th: 52.8 28.4 99.5th: 156.4 32.6 99.9th: 1990.2 52.0 Groups: 16 6.1_Base 6.1_Latency_Nice 50.0th: 26.0 21.0 75.0th: 33.0 27.8 90.0th: 39.6 34.4 95.0th: 43.4 38.6 99.0th: 66.8 48.8 99.5th: 170.6 60.6 99.9th: 3308.8 201.6 Groups: 32 6.1_Base 6.1_Latency_Nice 50.0th: 40.8 38.6 75.0th: 55.4 52.8 90.0th: 67.0 64.2 95.0th: 74.2 71.6 99.0th: 106.0 90.0 99.5th: 323.8 133.0 99.9th: 4789.6 459.2 Groups: 64 6.1_Base 6.1_Latency_Nice 50.0th: 72.6 68.2 75.0th: 103.4 97.8 90.0th: 127.6 120.0 95.0th: 141.2 132.0 99.0th: 343.4 158.4 99.5th: 1609.0 180.8 99.9th: 6571.2 686.6 Groups: 128 6.1_Base 6.1_Latency_Nice 50.0th: 147.2 147.2 75.0th: 216.4 217.2 90.0th: 268.4 268.2 95.0th: 300.6 294.8 99.0th: 3500.0 638.6 99.5th: 5995.2 2522.8 99.9th: 10390.4 9451.2 Groups: 256 6.1_Base 6.1_Latency_Nice 50.0th: 340.8 333.2 75.0th: 551.8 530.2 90.0th: 3528.4 1919.2 95.0th: 7312.8 5558.4 99.0th: 14630.4 12912.0 99.5th: 17955.2 14950.4 99.9th: 23059.2 20230.4 Groups: 512 6.1_Base 6.1_Latency_Nice 50.0th: 1021.8 990.6 75.0th: 9545.6 10044.8 90.0th: 20972.8 21638.4 95.0th: 29971.2 30291.2 99.0th: 42355.2 46707.2 99.5th: 48550.4 52057.6 99.9th: 58867.2 60147.2 Tested-by: shrikanth Hegde