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=-16.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 95C3FC433ED for ; Thu, 22 Apr 2021 10:24:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5B02B61458 for ; Thu, 22 Apr 2021 10:24:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235932AbhDVKZK (ORCPT ); Thu, 22 Apr 2021 06:25:10 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:34176 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S235877AbhDVKY6 (ORCPT ); Thu, 22 Apr 2021 06:24:58 -0400 Received: from pps.filterd (m0098416.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 13MA3VtN121664; Thu, 22 Apr 2021 06:24:03 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding; s=pp1; bh=0lfonzMjgGuLsMfJSIbTjpzf9KIbUe0NIUMFOewiXpY=; b=pAdpfbW88RJX2QEPt/oQRdOEPsNd1POYepwv3cWLEeqhh7+iUwd3dzgn3QcAMvVW7Dmr tjP/QdF9xm8DAuTeIk+RdNhedCeg+43LAcDoIO59e1nEYTxbQRGxsotdF+hFGwYvNOdH ce/mTxnaZtlMo2Eu4O0UZYj0i+9h94tX0rXRjaz5WJ0dnKmb4rQUvAuoaIOIlcPBvBT0 SIcrUEmMvLVE9moFGM0410FlZLukTioXB4gQlOzaLRIxOuOVfuFUZzPz6xob/9QWgoKt Dpd311j2a04flrkjPG6uVxRQU0oixs2CMMFg941XJyerOnGvEDD3LQqA42w6xVFgytO1 oQ== Received: from ppma06fra.de.ibm.com (48.49.7a9f.ip4.static.sl-reverse.com [159.122.73.72]) by mx0b-001b2d01.pphosted.com with ESMTP id 3835n0365t-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 22 Apr 2021 06:24:03 -0400 Received: from pps.filterd (ppma06fra.de.ibm.com [127.0.0.1]) by ppma06fra.de.ibm.com (8.16.0.43/8.16.0.43) with SMTP id 13MALsev013071; Thu, 22 Apr 2021 10:24:02 GMT Received: from b06avi18878370.portsmouth.uk.ibm.com (b06avi18878370.portsmouth.uk.ibm.com [9.149.26.194]) by ppma06fra.de.ibm.com with ESMTP id 37ypxh9j0q-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 22 Apr 2021 10:24:01 +0000 Received: from d06av26.portsmouth.uk.ibm.com (d06av26.portsmouth.uk.ibm.com [9.149.105.62]) by b06avi18878370.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 13MANabh18022744 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 22 Apr 2021 10:23:36 GMT Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 86C03AE05D; Thu, 22 Apr 2021 10:23:59 +0000 (GMT) Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id B7964AE053; Thu, 22 Apr 2021 10:23:56 +0000 (GMT) Received: from saptagiri.in.ibm.com (unknown [9.199.63.107]) by d06av26.portsmouth.uk.ibm.com (Postfix) with ESMTP; Thu, 22 Apr 2021 10:23:56 +0000 (GMT) From: Srikar Dronamraju To: Ingo Molnar , Peter Zijlstra Cc: LKML , Mel Gorman , Rik van Riel , Srikar Dronamraju , Thomas Gleixner , Valentin Schneider , Vincent Guittot , Dietmar Eggemann , Gautham R Shenoy , Parth Shah Subject: [PATCH 06/10] sched/idle: Move busy_cpu accounting to idle callback Date: Thu, 22 Apr 2021 15:53:22 +0530 Message-Id: <20210422102326.35889-7-srikar@linux.vnet.ibm.com> X-Mailer: git-send-email 2.26.3 In-Reply-To: <20210422102326.35889-1-srikar@linux.vnet.ibm.com> References: <20210422102326.35889-1-srikar@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: JCV6EUUr67Eb_yScyaYIorG4ZUZU3Ueo X-Proofpoint-GUID: JCV6EUUr67Eb_yScyaYIorG4ZUZU3Ueo X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.391,18.0.761 definitions=2021-04-22_04:2021-04-21,2021-04-22 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 adultscore=0 impostorscore=0 mlxscore=0 lowpriorityscore=0 bulkscore=0 suspectscore=0 spamscore=0 mlxlogscore=999 malwarescore=0 phishscore=0 priorityscore=1501 clxscore=1015 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2104060000 definitions=main-2104220084 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently we account nr_busy_cpus in no_hz idle functions. There is no reason why nr_busy_cpus should updated be in NO_HZ_COMMON configs only. Also scheduler can mark a CPU as non-busy as soon as an idle class task starts to run. Scheduler can then mark a CPU as busy as soon as its woken up from idle or a new task is placed on it's runqueue. Cc: LKML Cc: Gautham R Shenoy Cc: Parth Shah Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Valentin Schneider Cc: Dietmar Eggemann Cc: Mel Gorman Cc: Vincent Guittot Cc: Rik van Riel Signed-off-by: Srikar Dronamraju --- kernel/sched/fair.c | 6 ++++-- kernel/sched/idle.c | 29 +++++++++++++++++++++++++++-- kernel/sched/sched.h | 1 + kernel/sched/topology.c | 2 ++ 4 files changed, 34 insertions(+), 4 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index f8c98e544418..00bcf1d861b5 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -10384,7 +10384,10 @@ static void set_cpu_sd_state_busy(int cpu) goto unlock; sd->nohz_idle = 0; - atomic_inc(&sd->shared->nr_busy_cpus); + if (sd && per_cpu(is_idle, cpu)) { + atomic_add_unless(&sd->shared->nr_busy_cpus, 1, per_cpu(sd_llc_size, cpu)); + per_cpu(is_idle, cpu) = 0; + } unlock: rcu_read_unlock(); } @@ -10414,7 +10417,6 @@ static void set_cpu_sd_state_idle(int cpu) goto unlock; sd->nohz_idle = 1; - atomic_dec(&sd->shared->nr_busy_cpus); unlock: rcu_read_unlock(); } diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c index cc828f3efe71..e624a05e48bd 100644 --- a/kernel/sched/idle.c +++ b/kernel/sched/idle.c @@ -425,12 +425,25 @@ static void check_preempt_curr_idle(struct rq *rq, struct task_struct *p, int fl static void put_prev_task_idle(struct rq *rq, struct task_struct *prev) { -#ifdef CONFIG_SCHED_SMT +#ifdef CONFIG_SMP + struct sched_domain_shared *sds; int cpu = rq->cpu; +#ifdef CONFIG_SCHED_SMT if (static_branch_likely(&sched_smt_present)) set_core_busy(cpu); #endif + + rcu_read_lock(); + sds = rcu_dereference(per_cpu(sd_llc_shared, cpu)); + if (sds) { + if (per_cpu(is_idle, cpu)) { + atomic_inc(&sds->nr_busy_cpus); + per_cpu(is_idle, cpu) = 0; + } + } + rcu_read_unlock(); +#endif } static void set_next_task_idle(struct rq *rq, struct task_struct *next, bool first) @@ -442,9 +455,21 @@ static void set_next_task_idle(struct rq *rq, struct task_struct *next, bool fir struct task_struct *pick_next_task_idle(struct rq *rq) { struct task_struct *next = rq->idle; +#ifdef CONFIG_SMP + struct sched_domain_shared *sds; + int cpu = rq->cpu; - set_next_task_idle(rq, next, true); + rcu_read_lock(); + sds = rcu_dereference(per_cpu(sd_llc_shared, cpu)); + if (sds) { + atomic_add_unless(&sds->nr_busy_cpus, -1, 0); + per_cpu(is_idle, cpu) = 1; + } + rcu_read_unlock(); +#endif + + set_next_task_idle(rq, next, true); return next; } diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 5c0bd4b0e73a..baf8d9a4cb26 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -1483,6 +1483,7 @@ DECLARE_PER_CPU(int, sd_llc_id); #ifdef CONFIG_SCHED_SMT DECLARE_PER_CPU(int, smt_id); #endif +DECLARE_PER_CPU(int, is_idle); DECLARE_PER_CPU(struct sched_domain_shared __rcu *, sd_llc_shared); DECLARE_PER_CPU(struct sched_domain __rcu *, sd_numa); DECLARE_PER_CPU(struct sched_domain __rcu *, sd_asym_packing); diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c index 8db40c8a6ad0..00e4669bb241 100644 --- a/kernel/sched/topology.c +++ b/kernel/sched/topology.c @@ -647,6 +647,7 @@ DEFINE_PER_CPU(int, sd_llc_id); #ifdef CONFIG_SCHED_SMT DEFINE_PER_CPU(int, smt_id); #endif +DEFINE_PER_CPU(int, is_idle); DEFINE_PER_CPU(struct sched_domain_shared __rcu *, sd_llc_shared); DEFINE_PER_CPU(struct sched_domain __rcu *, sd_numa); DEFINE_PER_CPU(struct sched_domain __rcu *, sd_asym_packing); @@ -673,6 +674,7 @@ static void update_top_cache_domain(int cpu) #ifdef CONFIG_SCHED_SMT per_cpu(smt_id, cpu) = cpumask_first(cpu_smt_mask(cpu)); #endif + per_cpu(is_idle, cpu) = 1; rcu_assign_pointer(per_cpu(sd_llc_shared, cpu), sds); sd = lowest_flag_domain(cpu, SD_NUMA); -- 2.18.2