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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=unavailable 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 64D45C54FCC for ; Mon, 20 Apr 2020 08:29:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 45F7F214AF for ; Mon, 20 Apr 2020 08:29:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726208AbgDTI34 (ORCPT ); Mon, 20 Apr 2020 04:29:56 -0400 Received: from foss.arm.com ([217.140.110.172]:45042 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726100AbgDTI34 (ORCPT ); Mon, 20 Apr 2020 04:29:56 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 11C7030E; Mon, 20 Apr 2020 01:29:55 -0700 (PDT) Received: from [192.168.0.7] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 9BA1A3F6CF; Mon, 20 Apr 2020 01:29:48 -0700 (PDT) From: Dietmar Eggemann Subject: Re: [PATCH 1/2] sched/uclamp: Add a new sysctl to control RT default boost value To: Qais Yousef , Ingo Molnar , Peter Zijlstra Cc: Jonathan Corbet , Juri Lelli , Vincent Guittot , Steven Rostedt , Ben Segall , Mel Gorman , Luis Chamberlain , Kees Cook , Iurii Zaikin , Quentin Perret , Valentin Schneider , Patrick Bellasi , Pavan Kondeti , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org References: <20200403123020.13897-1-qais.yousef@arm.com> Message-ID: <292dbd54-e590-dc4f-41e6-5f86e478c0ee@arm.com> Date: Mon, 20 Apr 2020 10:29:46 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: <20200403123020.13897-1-qais.yousef@arm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On 03.04.20 14:30, Qais Yousef wrote: [...] > @@ -924,6 +945,14 @@ uclamp_eff_get(struct task_struct *p, enum uclamp_id clamp_id) > return uc_req; > } > > +static void uclamp_rt_sync_default_util_min(struct task_struct *p) > +{ > + struct uclamp_se *uc_se = &p->uclamp_req[UCLAMP_MIN]; > + > + if (!uc_se->user_defined) > + uclamp_se_set(uc_se, sysctl_sched_rt_default_uclamp_util_min, false); > +} > + > unsigned long uclamp_eff_value(struct task_struct *p, enum uclamp_id clamp_id) > { > struct uclamp_se uc_eff; > @@ -1030,6 +1059,12 @@ static inline void uclamp_rq_inc(struct rq *rq, struct task_struct *p) > if (unlikely(!p->sched_class->uclamp_enabled)) > return; > > + /* > + * When sysctl_sched_rt_default_uclamp_util_min value is changed by the > + * user, we apply any new value on the next wakeup, which is here. > + */ > + uclamp_rt_sync_default_util_min(p); > + Does this have to be an extra function? Can we not reuse uclamp_tg_restrict() by slightly rename it to uclamp_restrict()? This function will then deal with enforcing restrictions, whether system and taskgroup hierarchy related or default value (latter only for rt-min right now since the others are fixed) related. uclamp_eff_get() -> uclamp_restrict() is called from: 'enqueue_task(), uclamp_update_active() -> uclamp_rq_inc() -> uclamp_rq_inc_id()' and 'task_fits_capacity() -> clamp_task_util(), rt_task_fits_capacity() -> uclamp_eff_value()' and 'schedutil_cpu_util(), find_energy_efficient_cpu() -> uclamp_rq_util_with() -> uclamp_eff_value()' so there would be more check-points than the one in 'enqueue_task() -> uclamp_rq_inc()' now. Only lightly tested: ---8<--- From: Dietmar Eggemann Date: Sun, 19 Apr 2020 01:20:17 +0200 Subject: [PATCH] sched/core: uclamp: Move uclamp_rt_sync_default_util_min() into uclamp_tg_restrict() Signed-off-by: Dietmar Eggemann --- kernel/sched/core.c | 34 +++++++++++++++------------------- 1 file changed, 15 insertions(+), 19 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 8f4e0d5c7daf..6802113d6d4b 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -899,12 +899,22 @@ unsigned int uclamp_rq_max_value(struct rq *rq, enum uclamp_id clamp_id, } static inline struct uclamp_se -uclamp_tg_restrict(struct task_struct *p, enum uclamp_id clamp_id) +uclamp_restrict(struct task_struct *p, enum uclamp_id clamp_id) { - struct uclamp_se uc_req = p->uclamp_req[clamp_id]; -#ifdef CONFIG_UCLAMP_TASK_GROUP - struct uclamp_se uc_max; + struct uclamp_se uc_req, __maybe_unused uc_max; + + if (unlikely(rt_task(p)) && clamp_id == UCLAMP_MIN && + !uc_req.user_defined) { + struct uclamp_se *uc_se = &p->uclamp_req[UCLAMP_MIN]; + int rt_min = sysctl_sched_rt_default_uclamp_util_min; + + if (uc_se->value != rt_min) + uclamp_se_set(uc_se, rt_min, false); + } + uc_req = p->uclamp_req[clamp_id]; + +#ifdef CONFIG_UCLAMP_TASK_GROUP /* * Tasks in autogroups or root task group will be * restricted by system defaults. @@ -933,7 +943,7 @@ uclamp_tg_restrict(struct task_struct *p, enum uclamp_id clamp_id) static inline struct uclamp_se uclamp_eff_get(struct task_struct *p, enum uclamp_id clamp_id) { - struct uclamp_se uc_req = uclamp_tg_restrict(p, clamp_id); + struct uclamp_se uc_req = uclamp_restrict(p, clamp_id); struct uclamp_se uc_max = uclamp_default[clamp_id]; /* System default restrictions always apply */ @@ -943,14 +953,6 @@ uclamp_eff_get(struct task_struct *p, enum uclamp_id clamp_id) return uc_req; } -static void uclamp_rt_sync_default_util_min(struct task_struct *p) -{ - struct uclamp_se *uc_se = &p->uclamp_req[UCLAMP_MIN]; - - if (!uc_se->user_defined) - uclamp_se_set(uc_se, sysctl_sched_rt_default_uclamp_util_min, false); -} - unsigned long uclamp_eff_value(struct task_struct *p, enum uclamp_id clamp_id) { struct uclamp_se uc_eff; @@ -1057,12 +1059,6 @@ static inline void uclamp_rq_inc(struct rq *rq, struct task_struct *p) if (unlikely(!p->sched_class->uclamp_enabled)) return; - /* - * When sysctl_sched_rt_default_uclamp_util_min value is changed by the - * user, we apply any new value on the next wakeup, which is here. - */ - uclamp_rt_sync_default_util_min(p); - for_each_clamp_id(clamp_id) uclamp_rq_inc_id(rq, p, clamp_id); -- 2.17.1