From mboxrd@z Thu Jan 1 00:00:00 1970 From: Juri Lelli Subject: [PATCH 4/6] sched/deadline: Create DL BW alloc, free & check overflow interface Date: Wed, 29 Mar 2023 14:55:56 +0200 Message-ID: <20230329125558.255239-5-juri.lelli@redhat.com> References: <20230329125558.255239-1-juri.lelli@redhat.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1680094599; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=iaWZTicEe0Rf17O02C5dBoHMVec0v/VEmNZr7Wzl9CM=; b=jP/UsPQ1D1KbB5NLeq2T3VNT6kppjDWzrhzSlvi2kqfl2NjcVARIG3ZqyHC4lW8YVmr8q4 tDlYpmGuxRfxZT6PjQhmx1O2z1G+Z21aoG7s3tyX7SQWwuq0KLP3R6asLJ+GwPIjN4a9iu nP1l2+zEJowZEM11B3aQxbwC+7ArAl4= In-Reply-To: <20230329125558.255239-1-juri.lelli-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> List-ID: Content-Type: text/plain; charset="us-ascii" To: Peter Zijlstra , Ingo Molnar , Qais Yousef , Waiman Long , Tejun Heo , Zefan Li , Johannes Weiner , Hao Luo Cc: Dietmar Eggemann , Steven Rostedt , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, luca.abeni-5rdYK369eBLQB0XuIGIEkQ@public.gmane.org, claudio-YOzL5CV4y4YG1A2ADO40+w@public.gmane.org, tommaso.cucinotta-5rdYK369eBLQB0XuIGIEkQ@public.gmane.org, bristot-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, mathieu.poirier-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Vincent Guittot , Wei Wang , Rick Yiu , Quentin Perret , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Sudeep Holla , Juri Lelli From: Dietmar Eggemann Rework the existing dl_cpu_busy() interface which offers DL BW overflow checking and per-task DL BW allocation. Add dl_bw_free() as an interface to be able to free DL BW. It will be used to allow freeing of the DL BW request done during cpuset_can_attach() in case multiple controllers are attached to the cgroup next to the cpuset controller and one of the non-cpuset can_attach() fails. dl_bw_alloc() (and dl_bw_free()) now take a `u64 dl_bw` parameter instead of `struct task_struct *p` used in dl_cpu_busy(). This allows to allocate DL BW for a set of tasks too rater than only for a single task. Signed-off-by: Dietmar Eggemann Signed-off-by: Juri Lelli --- include/linux/sched.h | 2 ++ kernel/sched/core.c | 4 ++-- kernel/sched/deadline.c | 53 +++++++++++++++++++++++++++++++---------- kernel/sched/sched.h | 2 +- 4 files changed, 45 insertions(+), 16 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index 6d654eb4cabd..6f3d84e0ed08 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1848,6 +1848,8 @@ current_restore_flags(unsigned long orig_flags, unsigned long flags) extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial); extern int task_can_attach(struct task_struct *p, const struct cpumask *cs_effective_cpus); +extern int dl_bw_alloc(int cpu, u64 dl_bw); +extern void dl_bw_free(int cpu, u64 dl_bw); #ifdef CONFIG_SMP extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask); extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask); diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 179266ff653f..c83dae6b8586 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -9294,7 +9294,7 @@ int task_can_attach(struct task_struct *p, if (unlikely(cpu >= nr_cpu_ids)) return -EINVAL; - ret = dl_cpu_busy(cpu, p); + ret = dl_bw_alloc(cpu, p->dl.dl_bw); } out: @@ -9579,7 +9579,7 @@ static void cpuset_cpu_active(void) static int cpuset_cpu_inactive(unsigned int cpu) { if (!cpuhp_tasks_frozen) { - int ret = dl_cpu_busy(cpu, NULL); + int ret = dl_bw_check_overflow(cpu); if (ret) return ret; diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 8f92f0f87383..5b6965e0e537 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -3057,26 +3057,38 @@ int dl_cpuset_cpumask_can_shrink(const struct cpumask *cur, return ret; } -int dl_cpu_busy(int cpu, struct task_struct *p) +enum dl_bw_request { + dl_bw_req_check_overflow = 0, + dl_bw_req_alloc, + dl_bw_req_free +}; + +static int dl_bw_manage(enum dl_bw_request req, int cpu, u64 dl_bw) { - unsigned long flags, cap; + unsigned long flags; struct dl_bw *dl_b; - bool overflow; + bool overflow = 0; rcu_read_lock_sched(); dl_b = dl_bw_of(cpu); raw_spin_lock_irqsave(&dl_b->lock, flags); - cap = dl_bw_capacity(cpu); - overflow = __dl_overflow(dl_b, cap, 0, p ? p->dl.dl_bw : 0); - if (!overflow && p) { - /* - * We reserve space for this task in the destination - * root_domain, as we can't fail after this point. - * We will free resources in the source root_domain - * later on (see set_cpus_allowed_dl()). - */ - __dl_add(dl_b, p->dl.dl_bw, dl_bw_cpus(cpu)); + if (req == dl_bw_req_free) { + __dl_sub(dl_b, dl_bw, dl_bw_cpus(cpu)); + } else { + unsigned long cap = dl_bw_capacity(cpu); + + overflow = __dl_overflow(dl_b, cap, 0, dl_bw); + + if (req == dl_bw_req_alloc && !overflow) { + /* + * We reserve space in the destination + * root_domain, as we can't fail after this point. + * We will free resources in the source root_domain + * later on (see set_cpus_allowed_dl()). + */ + __dl_add(dl_b, dl_bw, dl_bw_cpus(cpu)); + } } raw_spin_unlock_irqrestore(&dl_b->lock, flags); @@ -3084,6 +3096,21 @@ int dl_cpu_busy(int cpu, struct task_struct *p) return overflow ? -EBUSY : 0; } + +int dl_bw_check_overflow(int cpu) +{ + return dl_bw_manage(dl_bw_req_check_overflow, cpu, 0); +} + +int dl_bw_alloc(int cpu, u64 dl_bw) +{ + return dl_bw_manage(dl_bw_req_alloc, cpu, dl_bw); +} + +void dl_bw_free(int cpu, u64 dl_bw) +{ + dl_bw_manage(dl_bw_req_free, cpu, dl_bw); +} #endif #ifdef CONFIG_SCHED_DEBUG diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 060616944d7a..81ecfd1a1a48 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -330,7 +330,7 @@ extern void __getparam_dl(struct task_struct *p, struct sched_attr *attr); extern bool __checkparam_dl(const struct sched_attr *attr); extern bool dl_param_changed(struct task_struct *p, const struct sched_attr *attr); extern int dl_cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial); -extern int dl_cpu_busy(int cpu, struct task_struct *p); +extern int dl_bw_check_overflow(int cpu); #ifdef CONFIG_CGROUP_SCHED -- 2.39.2