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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY,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 60794C49ED7 for ; Thu, 19 Sep 2019 07:20:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3A5B2206C2 for ; Thu, 19 Sep 2019 07:20:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731957AbfISHUc (ORCPT ); Thu, 19 Sep 2019 03:20:32 -0400 Received: from mailgw01.mediatek.com ([210.61.82.183]:29782 "EHLO mailgw01.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1727435AbfISHUb (ORCPT ); Thu, 19 Sep 2019 03:20:31 -0400 X-UUID: fc7af5658cfe446e889f9502c20999bf-20190919 X-UUID: fc7af5658cfe446e889f9502c20999bf-20190919 Received: from mtkexhb01.mediatek.inc [(172.21.101.102)] by mailgw01.mediatek.com (envelope-from ) (Cellopoint E-mail Firewall v4.1.10 Build 0809 with TLS) with ESMTP id 2040254327; Thu, 19 Sep 2019 15:20:25 +0800 Received: from mtkcas08.mediatek.inc (172.21.101.126) by mtkmbs07n1.mediatek.inc (172.21.101.16) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Thu, 19 Sep 2019 15:20:23 +0800 Received: from mtkswgap22.mediatek.inc (172.21.77.33) by mtkcas08.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1395.4 via Frontend Transport; Thu, 19 Sep 2019 15:20:21 +0800 From: YT Chang To: Peter Zijlstra , Matthias Brugger CC: , , , , YT Chang Subject: [PATCH 1/1] sched/eas: introduce system-wide overutil indicator Date: Thu, 19 Sep 2019 15:20:22 +0800 Message-ID: <1568877622-28073-1-git-send-email-yt.chang@mediatek.com> X-Mailer: git-send-email 1.9.1 MIME-Version: 1.0 Content-Type: text/plain X-MTK: N Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When the system is overutilization, the load-balance crossing clusters will be triggered and scheduler will not use energy aware scheduling to choose CPUs. The overutilization means the loading of ANY CPUs exceeds threshold (80%). However, only 1 heavy task or while-1 program will run on highest capacity CPUs and it still result to trigger overutilization. So the system will not use Energy Aware scheduling. To avoid it, a system-wide over-utilization indicator to trigger load-balance cross clusters. The policy is: The loading of "ALL CPUs in the highest capacity" exceeds threshold(80%) or The loading of "Any CPUs not in the highest capacity" exceed threshold(80%) Signed-off-by: YT Chang --- kernel/sched/fair.c | 76 +++++++++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 65 insertions(+), 11 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 036be95..f4c3d70 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -5182,10 +5182,71 @@ static inline bool cpu_overutilized(int cpu) static inline void update_overutilized_status(struct rq *rq) { if (!READ_ONCE(rq->rd->overutilized) && cpu_overutilized(rq->cpu)) { - WRITE_ONCE(rq->rd->overutilized, SG_OVERUTILIZED); - trace_sched_overutilized_tp(rq->rd, SG_OVERUTILIZED); + if (capacity_orig_of(cpu_of(rq)) < rq->rd->max_cpu_capacity) { + WRITE_ONCE(rq->rd->overutilized, SG_OVERUTILIZED); + trace_sched_overutilized_tp(rq->rd, SG_OVERUTILIZED); + } } } + +static +void update_system_overutilized(struct sched_domain *sd, struct cpumask *cpus) +{ + unsigned long group_util; + bool intra_overutil = false; + unsigned long max_capacity; + struct sched_group *group = sd->groups; + struct root_domain *rd; + int this_cpu; + bool overutilized; + int i; + + this_cpu = smp_processor_id(); + rd = cpu_rq(this_cpu)->rd; + overutilized = READ_ONCE(rd->overutilized); + max_capacity = rd->max_cpu_capacity; + + do { + group_util = 0; + for_each_cpu_and(i, sched_group_span(group), cpus) { + group_util += cpu_util(i); + if (cpu_overutilized(i)) { + if (capacity_orig_of(i) < max_capacity) { + intra_overutil = true; + break; + } + } + } + + /* + * A capacity base hint for over-utilization. + * Not to trigger system overutiled if heavy tasks + * in Big.cluster, so + * add the free room(20%) of Big.cluster is impacted which means + * system-wide over-utilization, + * that considers whole cluster not single cpu + */ + if (group->group_weight > 1 && (group->sgc->capacity * 1024 < + group_util * capacity_margin)) { + intra_overutil = true; + break; + } + + group = group->next; + + } while (group != sd->groups && !intra_overutil); + + if (overutilized != intra_overutil) { + if (intra_overutil == true) { + WRITE_ONCE(rd->overutilized, SG_OVERUTILIZED); + trace_sched_overutilized_tp(rd, SG_OVERUTILIZED); + } else { + WRITE_ONCE(rd->overutilized, 0); + trace_sched_overutilized_tp(rd, 0); + } + } +} + #else static inline void update_overutilized_status(struct rq *rq) { } #endif @@ -8242,15 +8303,6 @@ static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sd /* update overload indicator if we are at root domain */ WRITE_ONCE(rd->overload, sg_status & SG_OVERLOAD); - - /* Update over-utilization (tipping point, U >= 0) indicator */ - WRITE_ONCE(rd->overutilized, sg_status & SG_OVERUTILIZED); - trace_sched_overutilized_tp(rd, sg_status & SG_OVERUTILIZED); - } else if (sg_status & SG_OVERUTILIZED) { - struct root_domain *rd = env->dst_rq->rd; - - WRITE_ONCE(rd->overutilized, SG_OVERUTILIZED); - trace_sched_overutilized_tp(rd, SG_OVERUTILIZED); } } @@ -8476,6 +8528,8 @@ static struct sched_group *find_busiest_group(struct lb_env *env) */ update_sd_lb_stats(env, &sds); + update_system_overutilized(env->sd, env->cpus); + if (sched_energy_enabled()) { struct root_domain *rd = env->dst_rq->rd; -- 1.9.1