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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 E01BDC04E53 for ; Wed, 15 May 2019 13:53:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BA86020873 for ; Wed, 15 May 2019 13:53:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726997AbfEONxq (ORCPT ); Wed, 15 May 2019 09:53:46 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:56704 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725953AbfEONxq (ORCPT ); Wed, 15 May 2019 09:53:46 -0400 Received: from pps.filterd (m0098413.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x4FDqvgU123772 for ; Wed, 15 May 2019 09:53:45 -0400 Received: from e06smtp05.uk.ibm.com (e06smtp05.uk.ibm.com [195.75.94.101]) by mx0b-001b2d01.pphosted.com with ESMTP id 2sgjv0cs5a-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 15 May 2019 09:53:44 -0400 Received: from localhost by e06smtp05.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 15 May 2019 14:53:43 +0100 Received: from b06cxnps4076.portsmouth.uk.ibm.com (9.149.109.198) by e06smtp05.uk.ibm.com (192.168.101.135) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Wed, 15 May 2019 14:53:40 +0100 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x4FDrdda49479760 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 15 May 2019 13:53:39 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 4DAF852051; Wed, 15 May 2019 13:53:39 +0000 (GMT) Received: from localhost.localdomain.com (unknown [9.102.18.182]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTP id 50DC65204E; Wed, 15 May 2019 13:53:37 +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, dsmythies@telus.net Subject: [RFCv2 2/6] sched: Introduce switch to enable TurboSched mode Date: Wed, 15 May 2019 19:23:18 +0530 X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190515135322.19393-1-parth@linux.ibm.com> References: <20190515135322.19393-1-parth@linux.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 19051513-0020-0000-0000-0000033CFC9B X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19051513-0021-0000-0000-0000218FBF2A Message-Id: <20190515135322.19393-3-parth@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-05-15_08:,, 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=1015 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-1905150087 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 cgroups using the TurboSched feature. This allows to enable the feature on adding first cgroup classified as jitter, similarly disable the feature on removal of such last cgroup. Signed-off-by: Parth Shah --- kernel/sched/core.c | 20 ++++++++++++++++++++ kernel/sched/sched.h | 7 +++++++ 2 files changed, 27 insertions(+) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 77aa4aee4478..facbedd2554e 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -60,6 +60,26 @@ __read_mostly int scheduler_running; */ int sysctl_sched_rt_runtime = 950000; +DEFINE_STATIC_KEY_FALSE(__turbo_sched_enabled); +static DEFINE_SPINLOCK(turbo_sched_lock); +static int turbo_sched_count; + +void turbo_sched_get(void) +{ + spin_lock(&turbo_sched_lock); + if (!turbo_sched_count++) + static_branch_enable(&__turbo_sched_enabled); + spin_unlock(&turbo_sched_lock); +} + +void turbo_sched_put(void) +{ + spin_lock(&turbo_sched_lock); + if (!--turbo_sched_count) + static_branch_disable(&__turbo_sched_enabled); + spin_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 e75ffaf3ff34..0339964cdf43 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -2437,3 +2437,10 @@ 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 */ + +DECLARE_STATIC_KEY_FALSE(__turbo_sched_enabled); + +static inline bool is_turbosched_enabled(void) +{ + return static_branch_unlikely(&__turbo_sched_enabled); +} -- 2.17.1