Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753779AbdLDKYj (ORCPT ); Mon, 4 Dec 2017 05:24:39 -0500 Received: from mail-wm0-f68.google.com ([74.125.82.68]:41379 "EHLO mail-wm0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753724AbdLDKYe (ORCPT ); Mon, 4 Dec 2017 05:24:34 -0500 X-Google-Smtp-Source: AGs4zMZkc6xG9ZbvWJBfApmQHYAybPppTmgUfV5dwwaKrDnbbjdp0j8G4fK1TYfielBwPZ4HovIwEQ== From: Juri Lelli To: peterz@infradead.org, mingo@redhat.com, rjw@rjwysocki.net, viresh.kumar@linaro.org Cc: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, tglx@linutronix.de, vincent.guittot@linaro.org, rostedt@goodmis.org, luca.abeni@santannapisa.it, claudio@evidence.eu.com, tommaso.cucinotta@santannapisa.it, bristot@redhat.com, mathieu.poirier@linaro.org, tkjos@android.com, joelaf@google.com, morten.rasmussen@arm.com, dietmar.eggemann@arm.com, patrick.bellasi@arm.com, alessio.balsini@arm.com, juri.lelli@redhat.com, Juri Lelli , Ingo Molnar , "Rafael J . Wysocki" Subject: [RFC PATCH v2 8/8] sched/deadline: make bandwidth enforcement scale-invariant Date: Mon, 4 Dec 2017 11:23:25 +0100 Message-Id: <20171204102325.5110-9-juri.lelli@redhat.com> X-Mailer: git-send-email 2.14.3 In-Reply-To: <20171204102325.5110-1-juri.lelli@redhat.com> References: <20171204102325.5110-1-juri.lelli@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3304 Lines: 95 From: Juri Lelli Apply frequency and cpu scale-invariance correction factor to bandwidth enforcement (similar to what we already do to fair utilization tracking). Each delta_exec gets scaled considering current frequency and maximum cpu capacity; which means that the reservation runtime parameter (that need to be specified profiling the task execution at max frequency on biggest capacity core) gets thus scaled accordingly. Signed-off-by: Juri Lelli Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Rafael J. Wysocki Cc: Viresh Kumar Cc: Luca Abeni Cc: Claudio Scordino --- kernel/sched/deadline.c | 26 ++++++++++++++++++++++---- kernel/sched/fair.c | 2 -- kernel/sched/sched.h | 2 ++ 3 files changed, 24 insertions(+), 6 deletions(-) diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 40f12aab9250..741d2fe26f88 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -1151,7 +1151,8 @@ static void update_curr_dl(struct rq *rq) { struct task_struct *curr = rq->curr; struct sched_dl_entity *dl_se = &curr->dl; - u64 delta_exec; + u64 delta_exec, scaled_delta_exec; + int cpu = cpu_of(rq); if (!dl_task(curr) || !on_dl_rq(dl_se)) return; @@ -1185,9 +1186,26 @@ static void update_curr_dl(struct rq *rq) if (unlikely(dl_entity_is_special(dl_se))) return; - if (unlikely(dl_se->flags & SCHED_FLAG_RECLAIM)) - delta_exec = grub_reclaim(delta_exec, rq, &curr->dl); - dl_se->runtime -= delta_exec; + /* + * For tasks that participate in GRUB, we implement GRUB-PA: the + * spare reclaimed bandwidth is used to clock down frequency. + * + * For the others, we still need to scale reservation parameters + * according to current frequency and CPU maximum capacity. + */ + if (unlikely(dl_se->flags & SCHED_FLAG_RECLAIM)) { + scaled_delta_exec = grub_reclaim(delta_exec, + rq, + &curr->dl); + } else { + unsigned long scale_freq = arch_scale_freq_capacity(cpu); + unsigned long scale_cpu = arch_scale_cpu_capacity(NULL, cpu); + + scaled_delta_exec = cap_scale(delta_exec, scale_freq); + scaled_delta_exec = cap_scale(scaled_delta_exec, scale_cpu); + } + + dl_se->runtime -= scaled_delta_exec; throttle: if (dl_runtime_exceeded(dl_se) || dl_se->dl_yielded) { diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 535d9409f4af..5bc3273a5c1c 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -3091,8 +3091,6 @@ static u32 __accumulate_pelt_segments(u64 periods, u32 d1, u32 d3) return c1 + c2 + c3; } -#define cap_scale(v, s) ((v)*(s) >> SCHED_CAPACITY_SHIFT) - /* * Accumulate the three separate parts of the sum; d1 the remainder * of the last (incomplete) period, d2 the span of full periods and d3 diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 0022c649fabb..6d9d55e764fa 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -156,6 +156,8 @@ static inline int task_has_dl_policy(struct task_struct *p) return dl_policy(p->policy); } +#define cap_scale(v, s) ((v)*(s) >> SCHED_CAPACITY_SHIFT) + /* * !! For sched_setattr_nocheck() (kernel) only !! * -- 2.14.3