From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932409AbaIWQMw (ORCPT ); Tue, 23 Sep 2014 12:12:52 -0400 Received: from mail-wg0-f49.google.com ([74.125.82.49]:62787 "EHLO mail-wg0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756405AbaIWQJa (ORCPT ); Tue, 23 Sep 2014 12:09:30 -0400 From: Vincent Guittot To: peterz@infradead.org, mingo@kernel.org, linux-kernel@vger.kernel.org, preeti@linux.vnet.ibm.com, linux@arm.linux.org.uk, linux-arm-kernel@lists.infradead.org Cc: riel@redhat.com, Morten.Rasmussen@arm.com, efault@gmx.de, nicolas.pitre@linaro.org, linaro-kernel@lists.linaro.org, daniel.lezcano@linaro.org, dietmar.eggemann@arm.com, pjt@google.com, bsegall@google.com, Vincent Guittot Subject: [PATCH v6 1/6] sched: add per rq cpu_capacity_orig Date: Tue, 23 Sep 2014 18:08:00 +0200 Message-Id: <1411488485-10025-2-git-send-email-vincent.guittot@linaro.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1411488485-10025-1-git-send-email-vincent.guittot@linaro.org> References: <1411488485-10025-1-git-send-email-vincent.guittot@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This new field cpu_capacity_orig reflects the original capacity of a CPU before being altered by frequency scaling, rt tasks and/or IRQ The cpu_capacity_orig will be used in several places to detect when the capapcity of a CPU has been noticeably reduced so we can trig load balance to look for a CPU with better capacity. As an example, we can detect when a CPU handles a significant amount of irq (with CONFIG_IRQ_TIME_ACCOUNTING) but this CPU is seen as an idle CPU by scheduler whereas CPUs, which are really idle, are available In addition, this new cpu_capacity_orig will be used to evaluate the usage of a the CPU by CFS tasks Signed-off-by: Vincent Guittot Reviewed-by: Kamalesh Babulal --- kernel/sched/core.c | 2 +- kernel/sched/fair.c | 8 +++++++- kernel/sched/sched.h | 1 + 3 files changed, 9 insertions(+), 2 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 2a93b87..e20f203 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -7056,7 +7056,7 @@ void __init sched_init(void) #ifdef CONFIG_SMP rq->sd = NULL; rq->rd = NULL; - rq->cpu_capacity = SCHED_CAPACITY_SCALE; + rq->cpu_capacity = rq->cpu_capacity_orig = SCHED_CAPACITY_SCALE; rq->post_schedule = 0; rq->active_balance = 0; rq->next_balance = jiffies; diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 2a1e6ac..622f8b0 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -4092,6 +4092,11 @@ static unsigned long capacity_of(int cpu) return cpu_rq(cpu)->cpu_capacity; } +static unsigned long capacity_orig_of(int cpu) +{ + return cpu_rq(cpu)->cpu_capacity_orig; +} + static unsigned long cpu_avg_load_per_task(int cpu) { struct rq *rq = cpu_rq(cpu); @@ -5765,6 +5770,7 @@ static void update_cpu_capacity(struct sched_domain *sd, int cpu) capacity >>= SCHED_CAPACITY_SHIFT; + cpu_rq(cpu)->cpu_capacity_orig = capacity; sdg->sgc->capacity_orig = capacity; if (sched_feat(ARCH_CAPACITY)) @@ -5826,7 +5832,7 @@ void update_group_capacity(struct sched_domain *sd, int cpu) * Runtime updates will correct capacity_orig. */ if (unlikely(!rq->sd)) { - capacity_orig += capacity_of(cpu); + capacity_orig += capacity_orig_of(cpu); capacity += capacity_of(cpu); continue; } diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 1bc6aad..f332e45 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -575,6 +575,7 @@ struct rq { struct sched_domain *sd; unsigned long cpu_capacity; + unsigned long cpu_capacity_orig; unsigned char idle_balance; /* For active balancing */ -- 1.9.1