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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 CB97FC35DF5 for ; Tue, 25 Feb 2020 08:16:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A8BC62176D for ; Tue, 25 Feb 2020 08:16:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729736AbgBYIQd (ORCPT ); Tue, 25 Feb 2020 03:16:33 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:43308 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729360AbgBYIQd (ORCPT ); Tue, 25 Feb 2020 03:16:33 -0500 Received: from pps.filterd (m0098413.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 01P8E7U6014007 for ; Tue, 25 Feb 2020 03:16:31 -0500 Received: from e06smtp03.uk.ibm.com (e06smtp03.uk.ibm.com [195.75.94.99]) by mx0b-001b2d01.pphosted.com with ESMTP id 2yayb0jy27-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 25 Feb 2020 03:16:31 -0500 Received: from localhost by e06smtp03.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Tue, 25 Feb 2020 08:16:24 -0000 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06cxnps4075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 01P8GNgE47513644 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 25 Feb 2020 08:16:23 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 2E38152051; Tue, 25 Feb 2020 08:16:23 +0000 (GMT) Received: from localhost.localdomain (unknown [9.124.35.187]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTP id 8DCE75204E; Tue, 25 Feb 2020 08:16:20 +0000 (GMT) Subject: Re: [PATCH v4 2/4] sched/core: Propagate parent task's latency requirements to the child task To: Pavan Kondeti Cc: linux-kernel@vger.kernel.org, peterz@infradead.org, mingo@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, qais.yousef@arm.com, chris.hyser@oracle.com, patrick.bellasi@matbug.net, valentin.schneider@arm.com, David.Laight@ACULAB.COM, pjt@google.com, pavel@ucw.cz, tj@kernel.org, dhaval.giani@oracle.com, qperret@google.com, tim.c.chen@linux.intel.com References: <20200224085918.16955-1-parth@linux.ibm.com> <20200224085918.16955-3-parth@linux.ibm.com> <20200225063226.GJ28029@codeaurora.org> From: Parth Shah Date: Tue, 25 Feb 2020 13:46:19 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.4.0 MIME-Version: 1.0 In-Reply-To: <20200225063226.GJ28029@codeaurora.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 x-cbid: 20022508-0012-0000-0000-0000038A094B X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 20022508-0013-0000-0000-000021C6AB0C Message-Id: X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.138,18.0.572 definitions=2020-02-25_02:2020-02-21,2020-02-25 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 lowpriorityscore=0 mlxscore=0 bulkscore=0 mlxlogscore=999 clxscore=1015 suspectscore=0 spamscore=0 malwarescore=0 priorityscore=1501 impostorscore=0 adultscore=0 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2001150001 definitions=main-2002250068 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2/25/20 12:02 PM, Pavan Kondeti wrote: > On Mon, Feb 24, 2020 at 02:29:16PM +0530, Parth Shah wrote: >> Clone parent task's latency_nice attribute to the forked child task. >> >> Reset the latency_nice value to default value when the child task is >> set to sched_reset_on_fork. >> >> Signed-off-by: Parth Shah >> Reviewed-by: Qais Yousef >> --- >> kernel/sched/core.c | 4 ++++ >> 1 file changed, 4 insertions(+) >> >> diff --git a/kernel/sched/core.c b/kernel/sched/core.c >> index 377ec26e9159..65b6c00d6dac 100644 >> --- a/kernel/sched/core.c >> +++ b/kernel/sched/core.c >> @@ -2860,6 +2860,9 @@ int sched_fork(unsigned long clone_flags, struct task_struct *p) >> */ >> p->prio = current->normal_prio; >> >> + /* Propagate the parent's latency requirements to the child as well */ >> + p->latency_nice = current->latency_nice; >> + >> uclamp_fork(p); >> >> /* >> @@ -2876,6 +2879,7 @@ int sched_fork(unsigned long clone_flags, struct task_struct *p) >> p->prio = p->normal_prio = __normal_prio(p); >> set_load_weight(p, false); >> >> + p->latency_nice = DEFAULT_LATENCY_NICE; >> /* >> * We don't need the reset flag anymore after the fork. It has >> * fulfilled its duty: >> -- >> 2.17.2 >> > > LGTM. > > latency_nice value initialization is missing for the init_task. good catch. Will add that part too. Thanks for pointing out. - Parth > > Thanks, > Pavan >