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=-8.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT 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 43B63C48BD6 for ; Tue, 25 Jun 2019 04:37:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2784220665 for ; Tue, 25 Jun 2019 04:37:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726909AbfFYEhj (ORCPT ); Tue, 25 Jun 2019 00:37:39 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:40626 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726857AbfFYEhj (ORCPT ); Tue, 25 Jun 2019 00:37:39 -0400 Received: from pps.filterd (m0098410.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x5P4XgHR005408 for ; Tue, 25 Jun 2019 00:37:38 -0400 Received: from e06smtp07.uk.ibm.com (e06smtp07.uk.ibm.com [195.75.94.103]) by mx0a-001b2d01.pphosted.com with ESMTP id 2tbc928x4a-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 25 Jun 2019 00:37:38 -0400 Received: from localhost by e06smtp07.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 25 Jun 2019 05:37:36 +0100 Received: from b06cxnps3074.portsmouth.uk.ibm.com (9.149.109.194) by e06smtp07.uk.ibm.com (192.168.101.137) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Tue, 25 Jun 2019 05:37:32 +0100 Received: from d06av25.portsmouth.uk.ibm.com (d06av25.portsmouth.uk.ibm.com [9.149.105.61]) by b06cxnps3074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x5P4bV3B56688656 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 25 Jun 2019 04:37:31 GMT Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id C517011C04C; Tue, 25 Jun 2019 04:37:31 +0000 (GMT) Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 936B411C04A; Tue, 25 Jun 2019 04:37:30 +0000 (GMT) Received: from localhost.in.ibm.com (unknown [9.124.35.87]) by d06av25.portsmouth.uk.ibm.com (Postfix) with ESMTP; Tue, 25 Jun 2019 04:37:30 +0000 (GMT) From: Parth Shah To: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org Cc: mingo@redhat.com, peterz@infradead.org, dietmar.eggemann@arm.com, patrick.bellasi@arm.com Subject: [RFCv3 2/8] sched: Introduce switch to enable TurboSched mode Date: Tue, 25 Jun 2019 10:07:20 +0530 X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190625043726.21490-1-parth@linux.ibm.com> References: <20190625043726.21490-1-parth@linux.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 19062504-0028-0000-0000-0000037D46BF X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19062504-0029-0000-0000-0000243D6686 Message-Id: <20190625043726.21490-3-parth@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-06-25_03:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1906250036 Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org This patch creates a static key which allows to enable or disable TurboSched feature at runtime. This key is added in order to enable the TurboSched feature. The static key helps in optimizing the scheduler fast-path when the TurboSched feature is disabled. The patch also provides get/put methods to keep track of the tasks using the TurboSched feature. This allows to enable the feature on setting first task classified as jitter, similarly disable the feature on unsetting of such last task. Signed-off-by: Parth Shah --- kernel/sched/core.c | 20 ++++++++++++++++++++ kernel/sched/sched.h | 9 +++++++++ 2 files changed, 29 insertions(+) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 19c7204d6351..ef83725bd4b0 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -61,6 +61,26 @@ __read_mostly int scheduler_running; */ int sysctl_sched_rt_runtime = 950000; +DEFINE_STATIC_KEY_FALSE(__turbo_sched_enabled); +static DEFINE_MUTEX(turbo_sched_lock); +static int turbo_sched_count; + +void turbo_sched_get(void) +{ + mutex_lock(&turbo_sched_lock); + if (!turbo_sched_count++) + static_branch_enable(&__turbo_sched_enabled); + mutex_unlock(&turbo_sched_lock); +} + +void turbo_sched_put(void) +{ + mutex_lock(&turbo_sched_lock); + if (!--turbo_sched_count) + static_branch_disable(&__turbo_sched_enabled); + mutex_unlock(&turbo_sched_lock); +} + /* * __task_rq_lock - lock the rq @p resides on. */ diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index e5599b33ffb8..1f239a960a6d 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -2426,3 +2426,12 @@ static inline bool sched_energy_enabled(void) static inline bool sched_energy_enabled(void) { return false; } #endif /* CONFIG_ENERGY_MODEL && CONFIG_CPU_FREQ_GOV_SCHEDUTIL */ + +void turbo_sched_get(void); +void turbo_sched_put(void); +DECLARE_STATIC_KEY_FALSE(__turbo_sched_enabled); + +static inline bool is_turbosched_enabled(void) +{ + return static_branch_unlikely(&__turbo_sched_enabled); +} -- 2.17.1