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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C51BFC4332F for ; Tue, 7 Nov 2023 14:44:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234032AbjKGOor (ORCPT ); Tue, 7 Nov 2023 09:44:47 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57644 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230178AbjKGOop (ORCPT ); Tue, 7 Nov 2023 09:44:45 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 23B239E for ; Tue, 7 Nov 2023 06:44:41 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=NbdBthsvDmWc+b1OxzhoxxTD1DSyiCWn83dIxsFA2aA=; b=CHADnMQaqH1P4xMoHaxCAZOFSz /2XlC8cD/UTJ5/QsbvBN0t4+P2MLFdf+KRnHNV6nqgEUOUbX75qcrE8xBRm6rwJPd1Lsl5sjvLaaM QyDcpTqTgwEIkW/cYyvEPsF37lwf5s0fqgbIMrbYV0o6OzkYzZ/mKggyXuFypGZNcLq6/+Pxasq9f i0Efqmqdvvr6Yi421/rGjUNBcStOyLml7FrMXWsLLZpkQRwEhao4yvnXWLCXsHvLZnZwoQ4/MpThl nvY13XAVIesBVYwzvhen8Al+ke5USYbp4gTrcNWW6S/bIl2y1TJXGiq+Ti/anW5V0O/4U5sPoi8n+ cSQjkzlQ==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1r0NJY-00Cqlv-Nu; Tue, 07 Nov 2023 14:44:25 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id E13E630049D; Tue, 7 Nov 2023 15:44:24 +0100 (CET) Date: Tue, 7 Nov 2023 15:44:24 +0100 From: Peter Zijlstra To: Daniel Bristot de Oliveira Cc: Ingo Molnar , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , linux-kernel@vger.kernel.org, Luca Abeni , Tommaso Cucinotta , Thomas Gleixner , Joel Fernandes , Vineeth Pillai , Shuah Khan , Phil Auld Subject: Re: [PATCH v5 7/7] sched/fair: Fair server interface Message-ID: <20231107144424.GX8262@noisy.programming.kicks-ass.net> References: <26adad2378c8b15533e4f6216c2863341e587f57.1699095159.git.bristot@kernel.org> <20231106154042.GH3818@noisy.programming.kicks-ass.net> <9a7222ed-88f8-4a3f-9d83-09b7fb977c27@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <9a7222ed-88f8-4a3f-9d83-09b7fb977c27@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 06, 2023 at 05:29:49PM +0100, Daniel Bristot de Oliveira wrote: > I was thinking about moving the entire throttling machinery inside CONFIG_RT_GROUP_SCHED > for now, because GROUP_SCHED depends on it, no? This builds and boots.. --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -9930,8 +9930,6 @@ void __init sched_init(void) #endif /* CONFIG_RT_GROUP_SCHED */ } - init_rt_bandwidth(&def_rt_bandwidth, global_rt_period(), global_rt_runtime()); - #ifdef CONFIG_SMP init_defrootdomain(); #endif @@ -9986,7 +9984,6 @@ void __init sched_init(void) init_tg_cfs_entry(&root_task_group, &rq->cfs, NULL, i, NULL); #endif /* CONFIG_FAIR_GROUP_SCHED */ - rq->rt.rt_runtime = def_rt_bandwidth.rt_runtime; #ifdef CONFIG_RT_GROUP_SCHED init_tg_rt_entry(&root_task_group, &rq->rt, NULL, i, NULL); #endif --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -1480,6 +1480,7 @@ static void update_curr_dl_se(struct rq if (dl_se == &rq->fair_server) return; +#ifdef CONFIG_RT_GROUP_SCHED /* * Because -- for now -- we share the rt bandwidth, we need to * account our runtime there too, otherwise actual rt tasks @@ -1504,6 +1505,7 @@ static void update_curr_dl_se(struct rq rt_rq->rt_time += delta_exec; raw_spin_unlock(&rt_rq->rt_runtime_lock); } +#endif } void dl_server_update(struct sched_dl_entity *dl_se, s64 delta_exec) --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -8,10 +8,6 @@ int sched_rr_timeslice = RR_TIMESLICE; /* More than 4 hours if BW_SHIFT equals 20. */ static const u64 max_rt_runtime = MAX_BW; -static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun); - -struct rt_bandwidth def_rt_bandwidth; - /* * period over which we measure -rt task CPU usage in us. * default: 1s @@ -67,6 +63,40 @@ static int __init sched_rt_sysctl_init(v late_initcall(sched_rt_sysctl_init); #endif +void init_rt_rq(struct rt_rq *rt_rq) +{ + struct rt_prio_array *array; + int i; + + array = &rt_rq->active; + for (i = 0; i < MAX_RT_PRIO; i++) { + INIT_LIST_HEAD(array->queue + i); + __clear_bit(i, array->bitmap); + } + /* delimiter for bitsearch: */ + __set_bit(MAX_RT_PRIO, array->bitmap); + +#if defined CONFIG_SMP + rt_rq->highest_prio.curr = MAX_RT_PRIO-1; + rt_rq->highest_prio.next = MAX_RT_PRIO-1; + rt_rq->overloaded = 0; + plist_head_init(&rt_rq->pushable_tasks); +#endif /* CONFIG_SMP */ + /* We start is dequeued state, because no RT tasks are queued */ + rt_rq->rt_queued = 0; + +#ifdef CONFIG_RT_GROUP_SCHED + rt_rq->rt_time = 0; + rt_rq->rt_throttled = 0; + rt_rq->rt_runtime = 0; + raw_spin_lock_init(&rt_rq->rt_runtime_lock); +#endif +} + +#ifdef CONFIG_RT_GROUP_SCHED + +static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun); + static enum hrtimer_restart sched_rt_period_timer(struct hrtimer *timer) { struct rt_bandwidth *rt_b = @@ -131,35 +161,6 @@ static void start_rt_bandwidth(struct rt do_start_rt_bandwidth(rt_b); } -void init_rt_rq(struct rt_rq *rt_rq) -{ - struct rt_prio_array *array; - int i; - - array = &rt_rq->active; - for (i = 0; i < MAX_RT_PRIO; i++) { - INIT_LIST_HEAD(array->queue + i); - __clear_bit(i, array->bitmap); - } - /* delimiter for bitsearch: */ - __set_bit(MAX_RT_PRIO, array->bitmap); - -#if defined CONFIG_SMP - rt_rq->highest_prio.curr = MAX_RT_PRIO-1; - rt_rq->highest_prio.next = MAX_RT_PRIO-1; - rt_rq->overloaded = 0; - plist_head_init(&rt_rq->pushable_tasks); -#endif /* CONFIG_SMP */ - /* We start is dequeued state, because no RT tasks are queued */ - rt_rq->rt_queued = 0; - - rt_rq->rt_time = 0; - rt_rq->rt_throttled = 0; - rt_rq->rt_runtime = 0; - raw_spin_lock_init(&rt_rq->rt_runtime_lock); -} - -#ifdef CONFIG_RT_GROUP_SCHED static void destroy_rt_bandwidth(struct rt_bandwidth *rt_b) { hrtimer_cancel(&rt_b->rt_period_timer); @@ -254,9 +255,6 @@ int alloc_rt_sched_group(struct task_gro if (!tg->rt_se) goto err; - init_rt_bandwidth(&tg->rt_bandwidth, - ktime_to_ns(def_rt_bandwidth.rt_period), 0); - for_each_possible_cpu(i) { rt_rq = kzalloc_node(sizeof(struct rt_rq), GFP_KERNEL, cpu_to_node(i)); @@ -605,70 +603,6 @@ static inline struct rt_bandwidth *sched return &rt_rq->tg->rt_bandwidth; } -#else /* !CONFIG_RT_GROUP_SCHED */ - -static inline u64 sched_rt_runtime(struct rt_rq *rt_rq) -{ - return rt_rq->rt_runtime; -} - -static inline u64 sched_rt_period(struct rt_rq *rt_rq) -{ - return ktime_to_ns(def_rt_bandwidth.rt_period); -} - -typedef struct rt_rq *rt_rq_iter_t; - -#define for_each_rt_rq(rt_rq, iter, rq) \ - for ((void) iter, rt_rq = &rq->rt; rt_rq; rt_rq = NULL) - -#define for_each_sched_rt_entity(rt_se) \ - for (; rt_se; rt_se = NULL) - -static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se) -{ - return NULL; -} - -static inline void sched_rt_rq_enqueue(struct rt_rq *rt_rq) -{ - struct rq *rq = rq_of_rt_rq(rt_rq); - - if (!rt_rq->rt_nr_running) - return; - - enqueue_top_rt_rq(rt_rq); - resched_curr(rq); -} - -static inline void sched_rt_rq_dequeue(struct rt_rq *rt_rq) -{ - dequeue_top_rt_rq(rt_rq, rt_rq->rt_nr_running); -} - -static inline int rt_rq_throttled(struct rt_rq *rt_rq) -{ - return rt_rq->rt_throttled; -} - -static inline const struct cpumask *sched_rt_period_mask(void) -{ - return cpu_online_mask; -} - -static inline -struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu) -{ - return &cpu_rq(cpu)->rt; -} - -static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq) -{ - return &def_rt_bandwidth; -} - -#endif /* CONFIG_RT_GROUP_SCHED */ - bool sched_rt_bandwidth_account(struct rt_rq *rt_rq) { struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); @@ -860,7 +794,7 @@ static int do_sched_rt_period_timer(stru const struct cpumask *span; span = sched_rt_period_mask(); -#ifdef CONFIG_RT_GROUP_SCHED + /* * FIXME: isolated CPUs should really leave the root task group, * whether they are isolcpus or were isolated via cpusets, lest @@ -872,7 +806,7 @@ static int do_sched_rt_period_timer(stru */ if (rt_b == &root_task_group.rt_bandwidth) span = cpu_online_mask; -#endif + for_each_cpu(i, span) { int enqueue = 0; struct rt_rq *rt_rq = sched_rt_period_rt_rq(rt_b, i); @@ -939,18 +873,6 @@ static int do_sched_rt_period_timer(stru return idle; } -static inline int rt_se_prio(struct sched_rt_entity *rt_se) -{ -#ifdef CONFIG_RT_GROUP_SCHED - struct rt_rq *rt_rq = group_rt_rq(rt_se); - - if (rt_rq) - return rt_rq->highest_prio.curr; -#endif - - return rt_task_of(rt_se)->prio; -} - static int sched_rt_runtime_exceeded(struct rt_rq *rt_rq) { u64 runtime = sched_rt_runtime(rt_rq); @@ -994,6 +916,70 @@ static int sched_rt_runtime_exceeded(str return 0; } +#else /* !CONFIG_RT_GROUP_SCHED */ + +typedef struct rt_rq *rt_rq_iter_t; + +#define for_each_rt_rq(rt_rq, iter, rq) \ + for ((void) iter, rt_rq = &rq->rt; rt_rq; rt_rq = NULL) + +#define for_each_sched_rt_entity(rt_se) \ + for (; rt_se; rt_se = NULL) + +static inline struct rt_rq *group_rt_rq(struct sched_rt_entity *rt_se) +{ + return NULL; +} + +static inline void sched_rt_rq_enqueue(struct rt_rq *rt_rq) +{ + struct rq *rq = rq_of_rt_rq(rt_rq); + + if (!rt_rq->rt_nr_running) + return; + + enqueue_top_rt_rq(rt_rq); + resched_curr(rq); +} + +static inline void sched_rt_rq_dequeue(struct rt_rq *rt_rq) +{ + dequeue_top_rt_rq(rt_rq, rt_rq->rt_nr_running); +} + +static inline int rt_rq_throttled(struct rt_rq *rt_rq) +{ + return false; +} + +static inline const struct cpumask *sched_rt_period_mask(void) +{ + return cpu_online_mask; +} + +static inline +struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu) +{ + return &cpu_rq(cpu)->rt; +} + +static void __enable_runtime(struct rq *rq) { } +static void __disable_runtime(struct rq *rq) { } + +#endif /* CONFIG_RT_GROUP_SCHED */ + +static inline int rt_se_prio(struct sched_rt_entity *rt_se) +{ +#ifdef CONFIG_RT_GROUP_SCHED + struct rt_rq *rt_rq = group_rt_rq(rt_se); + + if (rt_rq) + return rt_rq->highest_prio.curr; +#endif + + return rt_task_of(rt_se)->prio; +} + /* * Update the current task's runtime statistics. Skip current tasks that * are not in our scheduling class. @@ -1001,7 +987,6 @@ static int sched_rt_runtime_exceeded(str static void update_curr_rt(struct rq *rq) { struct task_struct *curr = rq->curr; - struct sched_rt_entity *rt_se = &curr->rt; s64 delta_exec; if (curr->sched_class != &rt_sched_class) @@ -1011,6 +996,9 @@ static void update_curr_rt(struct rq *rq if (unlikely(delta_exec <= 0)) return; +#ifdef CONFIG_RT_GROUP_SCHED + struct sched_rt_entity *rt_se = &curr->rt; + if (!rt_bandwidth_enabled()) return; @@ -1029,6 +1017,7 @@ static void update_curr_rt(struct rq *rq do_start_rt_bandwidth(sched_rt_bandwidth(rt_rq)); } } +#endif } static void @@ -1185,7 +1174,6 @@ dec_rt_group(struct sched_rt_entity *rt_ static void inc_rt_group(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) { - start_rt_bandwidth(&def_rt_bandwidth); } static inline @@ -2913,19 +2901,6 @@ int sched_rt_can_attach(struct task_grou #ifdef CONFIG_SYSCTL static int sched_rt_global_constraints(void) { - unsigned long flags; - int i; - - raw_spin_lock_irqsave(&def_rt_bandwidth.rt_runtime_lock, flags); - for_each_possible_cpu(i) { - struct rt_rq *rt_rq = &cpu_rq(i)->rt; - - raw_spin_lock(&rt_rq->rt_runtime_lock); - rt_rq->rt_runtime = global_rt_runtime(); - raw_spin_unlock(&rt_rq->rt_runtime_lock); - } - raw_spin_unlock_irqrestore(&def_rt_bandwidth.rt_runtime_lock, flags); - return 0; } #endif /* CONFIG_SYSCTL */ @@ -2945,12 +2920,6 @@ static int sched_rt_global_validate(void static void sched_rt_do_global(void) { - unsigned long flags; - - raw_spin_lock_irqsave(&def_rt_bandwidth.rt_runtime_lock, flags); - def_rt_bandwidth.rt_runtime = global_rt_runtime(); - def_rt_bandwidth.rt_period = ns_to_ktime(global_rt_period()); - raw_spin_unlock_irqrestore(&def_rt_bandwidth.rt_runtime_lock, flags); } static int sched_rt_handler(struct ctl_table *table, int write, void *buffer, --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -698,13 +698,13 @@ struct rt_rq { #endif /* CONFIG_SMP */ int rt_queued; +#ifdef CONFIG_RT_GROUP_SCHED int rt_throttled; u64 rt_time; u64 rt_runtime; /* Nests inside the rq lock: */ raw_spinlock_t rt_runtime_lock; -#ifdef CONFIG_RT_GROUP_SCHED unsigned int rt_nr_boosted; struct rq *rq; @@ -2460,7 +2460,6 @@ extern void reweight_task(struct task_st extern void resched_curr(struct rq *rq); extern void resched_cpu(int cpu); -extern struct rt_bandwidth def_rt_bandwidth; extern void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime); extern bool sched_rt_bandwidth_account(struct rt_rq *rt_rq);