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 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 4748EC2BA4C for ; Wed, 26 Jan 2022 08:12:57 +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:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:CC:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=1EQJ5luYOR4uJkh9IB1nlueu6MDRcTDCVH7Ng/cEbZo=; b=FpQlnQcpssQz4A MLUURyUm3i3kAEci7G1RRG24tH2fhD7SsJXdMKIivS+z+ZuE0khhmUtjhDSUFbImP6KSJ0l4kHbzf f4SCGZqN4ti+69CbDTSTiHckZzj5WQ/S5BU/4xr+dv0Xz9ua5/B+9TTWM76QLCSls67YNoFFOiag0 njZIVDW5ROw3HUCd1nZEitRTcJML59Lh7WtmYj6JwbSnsdSGlBQSpb6XAbdJC0IpoG1kBAf6otas3 wePlmXoiBjq7mDxZdD5BfJkwEAKRYbqcbdfsXO+uR/eA3pr5DZamoPYKCH0dElXLPgdEuRDRAt/va PypX2T4GB6sjzbTM3DeQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nCdP5-00Ae8P-T1; Wed, 26 Jan 2022 08:11:44 +0000 Received: from szxga02-in.huawei.com ([45.249.212.188]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nCdOc-00AduL-KM for linux-arm-kernel@lists.infradead.org; Wed, 26 Jan 2022 08:11:16 +0000 Received: from canpemm500009.china.huawei.com (unknown [172.30.72.56]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4JkGbZ3D4gz9sJq; Wed, 26 Jan 2022 16:09:46 +0800 (CST) Received: from localhost.localdomain (10.67.164.66) by canpemm500009.china.huawei.com (7.192.105.203) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Wed, 26 Jan 2022 16:11:06 +0800 From: Yicong Yang To: , , , , , , , CC: , , , , , , , , , , <21cnbao@gmail.com>, , Subject: [PATCH v2 2/2] sched/fair: Scan cluster before scanning LLC in wake-up path Date: Wed, 26 Jan 2022 16:09:47 +0800 Message-ID: <20220126080947.4529-3-yangyicong@hisilicon.com> X-Mailer: git-send-email 2.31.0 In-Reply-To: <20220126080947.4529-1-yangyicong@hisilicon.com> References: <20220126080947.4529-1-yangyicong@hisilicon.com> MIME-Version: 1.0 X-Originating-IP: [10.67.164.66] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To canpemm500009.china.huawei.com (7.192.105.203) X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220126_001115_094266_81954B9B X-CRM114-Status: GOOD ( 16.11 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Barry Song For platforms having clusters like Kunpeng920, CPUs within the same cluster have lower latency when synchronizing and accessing shared resources like cache. Thus, this patch tries to find an idle cpu within the cluster of the target CPU before scanning the whole LLC to gain lower latency. Note neither Kunpeng920 nor x86 Jacobsville supports SMT, so this patch doesn't consider SMT for this moment. Testing has been done on Kunpeng920 by pinning tasks to one numa and two numa. On Kunpeng920, Each numa has 8 clusters and each cluster has 4 CPUs. With this patch, We noticed enhancement on tbench within one numa or cross two numa. On numa 0: 5.17-rc1 patched Hmean 1 324.73 ( 0.00%) 378.01 * 16.41%* Hmean 2 645.36 ( 0.00%) 754.63 * 16.93%* Hmean 4 1302.09 ( 0.00%) 1507.54 * 15.78%* Hmean 8 2612.03 ( 0.00%) 2982.57 * 14.19%* Hmean 16 5307.12 ( 0.00%) 5886.66 * 10.92%* Hmean 32 9354.22 ( 0.00%) 9908.13 * 5.92%* Hmean 64 7240.35 ( 0.00%) 7278.78 * 0.53%* Hmean 128 6186.40 ( 0.00%) 6187.85 ( 0.02%) On numa 0-1: 5.17-rc1 patched Hmean 1 320.01 ( 0.00%) 378.44 * 18.26%* Hmean 2 643.85 ( 0.00%) 752.52 * 16.88%* Hmean 4 1287.36 ( 0.00%) 1505.62 * 16.95%* Hmean 8 2564.60 ( 0.00%) 2955.29 * 15.23%* Hmean 16 5195.69 ( 0.00%) 5814.74 * 11.91%* Hmean 32 9769.16 ( 0.00%) 10872.63 * 11.30%* Hmean 64 15952.50 ( 0.00%) 17281.98 * 8.33%* Hmean 128 13113.77 ( 0.00%) 13895.20 * 5.96%* Hmean 256 10997.59 ( 0.00%) 11244.69 * 2.25%* Hmean 512 14623.60 ( 0.00%) 15526.25 * 6.17%* This will also help to improve the MySQL. With MySQL server running on numa 0 and client running on numa 1, both QPS and latency is imporved on read-write case: 5.17-rc1 patched QPS-16threads 143333.2633 145077.4033(+1.22%) QPS-24threads 195085.9367 202719.6133(+3.91%) QPS-32threads 241165.6867 249020.74(+3.26%) QPS-64threads 244586.8433 253387.7567(+3.60%) avg-lat-16threads 2.23 2.19(+1.19%) avg-lat-24threads 2.46 2.36(+3.79%) avg-lat-36threads 2.66 2.57(+3.26%) avg-lat-64threads 5.23 5.05(+3.44%) Tested-by: Yicong Yang Signed-off-by: Barry Song Signed-off-by: Yicong Yang --- kernel/sched/fair.c | 46 +++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 42 insertions(+), 4 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 5146163bfabb..2f84a933aedd 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -6262,12 +6262,46 @@ static inline int select_idle_smt(struct task_struct *p, struct sched_domain *sd #endif /* CONFIG_SCHED_SMT */ +#ifdef CONFIG_SCHED_CLUSTER +/* + * Scan the cluster domain for idle CPUs and clear cluster cpumask after scanning + */ +static inline int scan_cluster(struct task_struct *p, int prev_cpu, int target) +{ + struct cpumask *cpus = this_cpu_cpumask_var_ptr(select_idle_mask); + struct sched_domain *sd = rcu_dereference(per_cpu(sd_cluster, target)); + int cpu, idle_cpu; + + /* TODO: Support SMT case while a machine with both cluster and SMT born */ + if (!sched_smt_active() && sd) { + for_each_cpu_and(cpu, cpus, sched_domain_span(sd)) { + idle_cpu = __select_idle_cpu(cpu, p); + if ((unsigned int)idle_cpu < nr_cpumask_bits) + return idle_cpu; + } + + /* Don't ping-pong tasks in and out cluster frequently */ + if (cpus_share_resources(target, prev_cpu)) + return target; + + cpumask_andnot(cpus, cpus, sched_domain_span(sd)); + } + + return -1; +} +#else +static inline int scan_cluster(struct task_struct *p, int prev_cpu, int target) +{ + return -1; +} +#endif + /* * Scan the LLC domain for idle CPUs; this is dynamically regulated by * comparing the average scan cost (tracked in sd->avg_scan_cost) against the * average idle time for this rq (as found in rq->avg_idle). */ -static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, bool has_idle_core, int target) +static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, bool has_idle_core, int prev_cpu, int target) { struct cpumask *cpus = this_cpu_cpumask_var_ptr(select_idle_mask); int i, cpu, idle_cpu = -1, nr = INT_MAX; @@ -6282,6 +6316,10 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, bool cpumask_and(cpus, sched_domain_span(sd), p->cpus_ptr); + idle_cpu = scan_cluster(p, prev_cpu, target); + if ((unsigned int)idle_cpu < nr_cpumask_bits) + return idle_cpu; + if (sched_feat(SIS_PROP) && !has_idle_core) { u64 avg_cost, avg_idle, span_avg; unsigned long now = jiffies; @@ -6416,7 +6454,7 @@ static int select_idle_sibling(struct task_struct *p, int prev, int target) /* * If the previous CPU is cache affine and idle, don't be stupid: */ - if (prev != target && cpus_share_cache(prev, target) && + if (prev != target && cpus_share_resources(prev, target) && (available_idle_cpu(prev) || sched_idle_cpu(prev)) && asym_fits_capacity(task_util, prev)) return prev; @@ -6442,7 +6480,7 @@ static int select_idle_sibling(struct task_struct *p, int prev, int target) p->recent_used_cpu = prev; if (recent_used_cpu != prev && recent_used_cpu != target && - cpus_share_cache(recent_used_cpu, target) && + cpus_share_resources(recent_used_cpu, target) && (available_idle_cpu(recent_used_cpu) || sched_idle_cpu(recent_used_cpu)) && cpumask_test_cpu(p->recent_used_cpu, p->cpus_ptr) && asym_fits_capacity(task_util, recent_used_cpu)) { @@ -6483,7 +6521,7 @@ static int select_idle_sibling(struct task_struct *p, int prev, int target) } } - i = select_idle_cpu(p, sd, has_idle_core, target); + i = select_idle_cpu(p, sd, has_idle_core, prev, target); if ((unsigned)i < nr_cpumask_bits) return i; -- 2.24.0 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel