From patchwork Fri Sep 8 22:49:15 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Elliot Berman X-Patchwork-Id: 13377881 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 5767BEEB56E for ; Fri, 8 Sep 2023 22:50:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344332AbjIHWu7 (ORCPT ); Fri, 8 Sep 2023 18:50:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60814 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240516AbjIHWu6 (ORCPT ); Fri, 8 Sep 2023 18:50:58 -0400 Received: from mx0a-0031df01.pphosted.com (mx0a-0031df01.pphosted.com [205.220.168.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D634A1FEB; Fri, 8 Sep 2023 15:50:54 -0700 (PDT) Received: from pps.filterd (m0279866.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 388Mog7D028246; Fri, 8 Sep 2023 22:50:42 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h=from : date : subject : mime-version : content-type : content-transfer-encoding : message-id : references : in-reply-to : to : cc; s=qcppdkim1; bh=Z55Ngw5xTpzSsoj7Y26jds8w0rVV/0ec9ylNE7GINhk=; b=jv9+dO0C6X85KKgNvwfzSt0AaReQaqN4kQ5Zbo7PMgqzTQ1z6EM1dOaClf6o+4SvL1jj 5uETzmBXpV2f7N/aiNopSY/s+aevPrP1IPS4b41nqkaq6IPxWAT5TQ2ge2Ye2rsenxxD 6YV6lh+oZLEKnOYigKE7c9m3JhI15o1TfWjRLcQRHTIb98EgP4KAtX3YOyxEOTi5ex5c xGHsfUAFQJux/SvZ7r/vEfMXmGk92nT/P8LgAFYLT8a+eDhYyQH5EjPsmFOXm0t0Nn2i Rcu88jfMdzA605xuff1uQWVWVoAHcYXG4+wtfHs2kf6V0BfjH4nToz2FkZpn/aNU/geS Nw== Received: from nasanppmta02.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3t023wsj44-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 08 Sep 2023 22:50:42 +0000 Received: from nasanex01b.na.qualcomm.com (nasanex01b.na.qualcomm.com [10.46.141.250]) by NASANPPMTA02.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTPS id 388MofIS010603 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 8 Sep 2023 22:50:41 GMT Received: from hu-eberman-lv.qualcomm.com (10.49.16.6) by nasanex01b.na.qualcomm.com (10.46.141.250) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1118.36; Fri, 8 Sep 2023 15:50:38 -0700 From: Elliot Berman Date: Fri, 8 Sep 2023 15:49:15 -0700 Subject: [PATCH v4 1/2] sched/core: Remove ifdeffery for saved_state MIME-Version: 1.0 Message-ID: <20230908-avoid-spurious-freezer-wakeups-v4-1-6155aa3dafae@quicinc.com> References: <20230908-avoid-spurious-freezer-wakeups-v4-0-6155aa3dafae@quicinc.com> In-Reply-To: <20230908-avoid-spurious-freezer-wakeups-v4-0-6155aa3dafae@quicinc.com> To: Ingo Molnar , Peter Zijlstra , "Rafael J. Wysocki" , Pavel Machek CC: Thomas Gleixner , , , , , Elliot Berman X-Mailer: b4 0.13-dev X-Originating-IP: [10.49.16.6] X-ClientProxiedBy: nalasex01c.na.qualcomm.com (10.47.97.35) To nasanex01b.na.qualcomm.com (10.46.141.250) X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-GUID: hzGfnqt_xYlvVJstTZOQcLm5PtEBGO2w X-Proofpoint-ORIG-GUID: hzGfnqt_xYlvVJstTZOQcLm5PtEBGO2w X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.267,Aquarius:18.0.957,Hydra:6.0.601,FMLib:17.11.176.26 definitions=2023-09-08_18,2023-09-05_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 phishscore=0 spamscore=0 priorityscore=1501 mlxlogscore=892 mlxscore=0 suspectscore=0 impostorscore=0 lowpriorityscore=0 bulkscore=0 clxscore=1015 adultscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2308100000 definitions=main-2309080209 Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org In preparation for freezer to also use saved_state, remove the CONFIG_PREEMPT_RT compilation guard around saved_state. On the arm64 platform I tested which did not have CONFIG_PREEMPT_RT, there was no statistically significant deviation by applying this patch. Test methodology: perf bench sched message -g 40 -l 40 Signed-off-by: Elliot Berman --- include/linux/sched.h | 2 -- kernel/sched/core.c | 17 +++-------------- 2 files changed, 3 insertions(+), 16 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index 609bde814cb0..14194a62294f 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -745,10 +745,8 @@ struct task_struct { #endif unsigned int __state; -#ifdef CONFIG_PREEMPT_RT /* saved state for "spinlock sleepers" */ unsigned int saved_state; -#endif /* * This begins the randomizable portion of task_struct. Only diff --git a/kernel/sched/core.c b/kernel/sched/core.c index c52c2eba7c73..58921ab7442b 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2219,31 +2219,21 @@ int __task_state_match(struct task_struct *p, unsigned int state) if (READ_ONCE(p->__state) & state) return 1; -#ifdef CONFIG_PREEMPT_RT if (READ_ONCE(p->saved_state) & state) return -1; -#endif + return 0; } static __always_inline int task_state_match(struct task_struct *p, unsigned int state) { -#ifdef CONFIG_PREEMPT_RT - int match; - /* * Serialize against current_save_and_set_rtlock_wait_state() and * current_restore_rtlock_saved_state(). */ - raw_spin_lock_irq(&p->pi_lock); - match = __task_state_match(p, state); - raw_spin_unlock_irq(&p->pi_lock); - - return match; -#else + guard(raw_spinlock_irq)(&p->pi_lock); return __task_state_match(p, state); -#endif } /* @@ -4053,7 +4043,6 @@ bool ttwu_state_match(struct task_struct *p, unsigned int state, int *success) *success = !!(match = __task_state_match(p, state)); -#ifdef CONFIG_PREEMPT_RT /* * Saved state preserves the task state across blocking on * an RT lock. If the state matches, set p::saved_state to @@ -4069,7 +4058,7 @@ bool ttwu_state_match(struct task_struct *p, unsigned int state, int *success) */ if (match < 0) p->saved_state = TASK_RUNNING; -#endif + return match > 0; }