From patchwork Fri Oct 20 13:43:37 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Zijlstra X-Patchwork-Id: 13430764 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 64547C001DF for ; Fri, 20 Oct 2023 13:44:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=lMFXD3pnN+Ywx9P+Hh8tFqTt47Fb0pJg41zxfPmI+yU=; b=ibSnl2oi6tZDsd CEzQv4ADeq0g6pWeGP8+kr7NcdMq+voYsuQTdZY8R+EedmEVKuxmPl3cWGu6YtLynJA23az+NapVm X70Fmn+KVudIMvrUZ1rHJQfZvDtVi92QM4YMpY1mXXWcI214FUhfw6VQ4LEREYoATjIMXhXxgF3bJ xo1CJhWvMJo0nqe3BQcJJV8SUu3iKjrV0uTYUIXOIII4GzomJ0stLlEDNF2ffTXHwPogYVYiWWPv6 956X58UJliVmSufO6Yq/gKTB8w4TR4uzunQdf7wOBsnKBdqypVKWSbsrknu2oS+z9HigdpuVe9VSg lxuTxMXt+vNasr5jCmig==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qtpmw-002PKf-2t; Fri, 20 Oct 2023 13:43:42 +0000 Received: from casper.infradead.org ([2001:8b0:10b:1236::1]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qtpmv-002PJk-1l for linux-arm-kernel@bombadil.infradead.org; Fri, 20 Oct 2023 13:43:41 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=VtM4fZvfkrGP76noU6hoHZ7O8+G+x3ssq63G10tuoB0=; b=FbZu5DGm6rwLX9Tb2SzEf9Jqqi ypsCIfvuVb7UuqsjmvA3xKHhsrOkP7XJCXM9EAIk93OK0ViQElE27AkiEPWmpZA03soRwDFgpWHEb HgvttCTMxpqDJA9S0EZFenzPXi/G3SgmaSF/8O70XRJSZpgcTt0EJoeijiZO9SYgl11f5OkCiZms6 qx8zRNI+qdzjdqyPayxNvdRA129rhkdI/yXk2t86MRF5Nq4b4dSw/ArFdEOXH4yLcSYTZbTJxWdPZ oOIdLqjgHCarypugH3yY+KMwy9Cw2Q8HVmHbbz4i44CHbnPwAdua9UaDoEuUOOmNUEyD1STVw8Lro iFjCuLVg==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1qtpms-00DQUw-Fn; Fri, 20 Oct 2023 13:43:38 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id CA0AB300392; Fri, 20 Oct 2023 15:43:37 +0200 (CEST) Date: Fri, 20 Oct 2023 15:43:37 +0200 From: Peter Zijlstra To: Yicong Yang Cc: mingo@redhat.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, tim.c.chen@linux.intel.com, yu.c.chen@intel.com, gautham.shenoy@amd.com, mgorman@suse.de, vschneid@redhat.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, rostedt@goodmis.org, bsegall@google.com, bristot@redhat.com, prime.zeng@huawei.com, yangyicong@hisilicon.com, jonathan.cameron@huawei.com, ego@linux.vnet.ibm.com, srikar@linux.vnet.ibm.com, linuxarm@huawei.com, 21cnbao@gmail.com, kprateek.nayak@amd.com, wuyun.abel@bytedance.com Subject: [PATCH] sched/fair: Remove SIS_PROP Message-ID: <20231020134337.GD33965@noisy.programming.kicks-ass.net> References: <20231019033323.54147-1-yangyicong@huawei.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20231019033323.54147-1-yangyicong@huawei.com> X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Since this had me looking at all that code, I did the below. Holler if there's objections etc.. Acked-by: Vincent Guittot Reviewed-by: Yicong Yang Acked-by: Mel Gorman --- Subject: sched/fair: Remove SIS_PROP From: Peter Zijlstra Date: Fri Oct 20 12:35:33 CEST 2023 SIS_UTIL seems to work well, lets remove the old thing. Signed-off-by: Peter Zijlstra (Intel) --- include/linux/sched/topology.h | 2 - kernel/sched/core.c | 5 ---- kernel/sched/fair.c | 48 ----------------------------------------- kernel/sched/features.h | 1 kernel/sched/sched.h | 3 -- 5 files changed, 59 deletions(-) --- a/include/linux/sched/topology.h +++ b/include/linux/sched/topology.h @@ -109,8 +109,6 @@ struct sched_domain { u64 max_newidle_lb_cost; unsigned long last_decay_max_lb_cost; - u64 avg_scan_cost; /* select_idle_sibling */ - #ifdef CONFIG_SCHEDSTATS /* load_balance() stats */ unsigned int lb_count[CPU_MAX_IDLE_TYPES]; --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -3792,9 +3792,6 @@ ttwu_do_activate(struct rq *rq, struct t if (rq->avg_idle > max) rq->avg_idle = max; - rq->wake_stamp = jiffies; - rq->wake_avg_idle = rq->avg_idle / 2; - rq->idle_stamp = 0; } #endif @@ -9991,8 +9988,6 @@ void __init sched_init(void) rq->online = 0; rq->idle_stamp = 0; rq->avg_idle = 2*sysctl_sched_migration_cost; - rq->wake_stamp = jiffies; - rq->wake_avg_idle = rq->avg_idle; rq->max_idle_balance_cost = sysctl_sched_migration_cost; INIT_LIST_HEAD(&rq->cfs_tasks); --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -7209,45 +7209,9 @@ static int select_idle_cpu(struct task_s struct cpumask *cpus = this_cpu_cpumask_var_ptr(select_rq_mask); int i, cpu, idle_cpu = -1, nr = INT_MAX; struct sched_domain_shared *sd_share; - struct rq *this_rq = this_rq(); - int this = smp_processor_id(); - struct sched_domain *this_sd = NULL; - u64 time = 0; cpumask_and(cpus, sched_domain_span(sd), p->cpus_ptr); - if (sched_feat(SIS_PROP) && !has_idle_core) { - u64 avg_cost, avg_idle, span_avg; - unsigned long now = jiffies; - - this_sd = rcu_dereference(*this_cpu_ptr(&sd_llc)); - if (!this_sd) - return -1; - - /* - * If we're busy, the assumption that the last idle period - * predicts the future is flawed; age away the remaining - * predicted idle time. - */ - if (unlikely(this_rq->wake_stamp < now)) { - while (this_rq->wake_stamp < now && this_rq->wake_avg_idle) { - this_rq->wake_stamp++; - this_rq->wake_avg_idle >>= 1; - } - } - - avg_idle = this_rq->wake_avg_idle; - avg_cost = this_sd->avg_scan_cost + 1; - - span_avg = sd->span_weight * avg_idle; - if (span_avg > 4*avg_cost) - nr = div_u64(span_avg, avg_cost); - else - nr = 4; - - time = cpu_clock(this); - } - if (sched_feat(SIS_UTIL)) { sd_share = rcu_dereference(per_cpu(sd_llc_shared, target)); if (sd_share) { @@ -7301,18 +7265,6 @@ static int select_idle_cpu(struct task_s if (has_idle_core) set_idle_cores(target, false); - if (sched_feat(SIS_PROP) && this_sd && !has_idle_core) { - time = cpu_clock(this) - time; - - /* - * Account for the scan cost of wakeups against the average - * idle time. - */ - this_rq->wake_avg_idle -= min(this_rq->wake_avg_idle, time); - - update_avg(&this_sd->avg_scan_cost, time); - } - return idle_cpu; } --- a/kernel/sched/features.h +++ b/kernel/sched/features.h @@ -49,7 +49,6 @@ SCHED_FEAT(TTWU_QUEUE, true) /* * When doing wakeups, attempt to limit superfluous scans of the LLC domain. */ -SCHED_FEAT(SIS_PROP, false) SCHED_FEAT(SIS_UTIL, true) /* --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -1059,9 +1059,6 @@ struct rq { u64 idle_stamp; u64 avg_idle; - unsigned long wake_stamp; - u64 wake_avg_idle; - /* This is used to determine avg_idle's max value */ u64 max_idle_balance_cost;