From: Patrick Bellasi <patrick.bellasi@arm.com>
To: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org,
linux-api@vger.kernel.org
Cc: Ingo Molnar <mingo@redhat.com>,
Peter Zijlstra <peterz@infradead.org>, Tejun Heo <tj@kernel.org>,
"Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
Vincent Guittot <vincent.guittot@linaro.org>,
Viresh Kumar <viresh.kumar@linaro.org>,
Paul Turner <pjt@google.com>,
Quentin Perret <quentin.perret@arm.com>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Morten Rasmussen <morten.rasmussen@arm.com>,
Juri Lelli <juri.lelli@redhat.com>, Todd Kjos <tkjos@google.com>,
Joel Fernandes <joelaf@google.com>,
Steve Muckle <smuckle@google.com>,
Suren Baghdasaryan <surenb@google.com>
Subject: [PATCH v6 14/16] sched/core: uclamp: Map TG's clamp values into CPU's clamp buckets
Date: Tue, 15 Jan 2019 10:15:11 +0000 [thread overview]
Message-ID: <20190115101513.2822-15-patrick.bellasi@arm.com> (raw)
In-Reply-To: <20190115101513.2822-1-patrick.bellasi@arm.com>
Utilization clamping requires to map each different clamp value into one
of the available clamp buckets used at {en,de}queue time (fast-path).
Each time a TG's clamp value sysfs attribute is updated via:
cpu_util_{min,max}_write_u64()
we need to update the task group reference to the new value's clamp
bucket and release the reference to the previous one.
Ensure that, whenever a task group is assigned a specific clamp_value,
this is properly translated into a unique clamp bucket to be used in the
fast-path. Do it by slightly refactoring uclamp_bucket_inc() to make the
(*task_struct) parameter optional and by reusing the code already
available for the per-task API.
Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
---
Changes in v6:
Others:
- wholesale s/group/bucket/
- wholesale s/_{get,put}/_{inc,dec}/ to match refcount APIs
---
include/linux/sched.h | 4 ++--
kernel/sched/core.c | 53 +++++++++++++++++++++++++++++++++----------
2 files changed, 43 insertions(+), 14 deletions(-)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 05d286524d70..3f02128fe6b2 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -617,8 +617,8 @@ struct sched_dl_entity {
* uclamp_bucket_dec() - for the old clamp value
*
* The active bit is set whenever a task has got an effective clamp bucket
- * and value assigned, which can be different from the user requested ones.
- * This allows to know a task is actually refcounting a CPU's clamp bucket.
+ * and value assigned, and it allows to know a task is actually refcounting a
+ * CPU's clamp bucket.
*/
struct uclamp_se {
unsigned int value : bits_per(SCHED_CAPACITY_SCALE);
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index ddbd591b305c..734b769db2ca 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1298,9 +1298,9 @@ static void __init init_uclamp(void)
#ifdef CONFIG_UCLAMP_TASK_GROUP
/* Init root TG's clamp bucket */
uc_se = &root_task_group.uclamp[clamp_id];
- uc_se->value = uclamp_none(clamp_id);
- uc_se->bucket_id = 0;
- uc_se->effective.value = uclamp_none(clamp_id);
+ uclamp_bucket_inc(NULL, uc_se, clamp_id, uclamp_none(UCLAMP_MAX));
+ uc_se->effective.bucket_id = uc_se->bucket_id;
+ uc_se->effective.value = uc_se->value;
#endif
}
}
@@ -6880,6 +6880,16 @@ void ia64_set_curr_task(int cpu, struct task_struct *p)
/* task_group_lock serializes the addition/removal of task groups */
static DEFINE_SPINLOCK(task_group_lock);
+static inline void free_uclamp_sched_group(struct task_group *tg)
+{
+#ifdef CONFIG_UCLAMP_TASK_GROUP
+ int clamp_id;
+
+ for (clamp_id = 0; clamp_id < UCLAMP_CNT; ++clamp_id)
+ uclamp_bucket_dec(clamp_id, tg->uclamp[clamp_id].bucket_id);
+#endif
+}
+
static inline int alloc_uclamp_sched_group(struct task_group *tg,
struct task_group *parent)
{
@@ -6887,12 +6897,12 @@ static inline int alloc_uclamp_sched_group(struct task_group *tg,
int clamp_id;
for (clamp_id = 0; clamp_id < UCLAMP_CNT; ++clamp_id) {
- tg->uclamp[clamp_id].value =
- parent->uclamp[clamp_id].value;
- tg->uclamp[clamp_id].bucket_id =
- parent->uclamp[clamp_id].bucket_id;
+ uclamp_bucket_inc(NULL, &tg->uclamp[clamp_id], clamp_id,
+ parent->uclamp[clamp_id].value);
tg->uclamp[clamp_id].effective.value =
parent->uclamp[clamp_id].effective.value;
+ tg->uclamp[clamp_id].effective.bucket_id =
+ parent->uclamp[clamp_id].effective.bucket_id;
}
#endif
@@ -6901,6 +6911,7 @@ static inline int alloc_uclamp_sched_group(struct task_group *tg,
static void sched_free_group(struct task_group *tg)
{
+ free_uclamp_sched_group(tg);
free_fair_sched_group(tg);
free_rt_sched_group(tg);
autogroup_free(tg);
@@ -7147,7 +7158,8 @@ static void cpu_cgroup_attach(struct cgroup_taskset *tset)
#ifdef CONFIG_UCLAMP_TASK_GROUP
static void cpu_util_update_hier(struct cgroup_subsys_state *css,
- int clamp_id, unsigned int value)
+ unsigned int clamp_id, unsigned int bucket_id,
+ unsigned int value)
{
struct cgroup_subsys_state *top_css = css;
struct uclamp_se *uc_se, *uc_parent;
@@ -7159,8 +7171,10 @@ static void cpu_util_update_hier(struct cgroup_subsys_state *css,
* groups we consider their current value.
*/
uc_se = &css_tg(css)->uclamp[clamp_id];
- if (css != top_css)
+ if (css != top_css) {
value = uc_se->value;
+ bucket_id = uc_se->effective.bucket_id;
+ }
/*
* Skip the whole subtrees if the current effective clamp is
@@ -7176,12 +7190,15 @@ static void cpu_util_update_hier(struct cgroup_subsys_state *css,
}
/* Propagate the most restrictive effective value */
- if (uc_parent->effective.value < value)
+ if (uc_parent->effective.value < value) {
value = uc_parent->effective.value;
+ bucket_id = uc_parent->effective.bucket_id;
+ }
if (uc_se->effective.value == value)
continue;
uc_se->effective.value = value;
+ uc_se->effective.bucket_id = bucket_id;
}
}
@@ -7194,6 +7211,7 @@ static int cpu_util_min_write_u64(struct cgroup_subsys_state *css,
if (min_value > SCHED_CAPACITY_SCALE)
return -ERANGE;
+ mutex_lock(&uclamp_mutex);
rcu_read_lock();
tg = css_tg(css);
@@ -7204,11 +7222,16 @@ static int cpu_util_min_write_u64(struct cgroup_subsys_state *css,
goto out;
}
+ /* Update TG's reference count */
+ uclamp_bucket_inc(NULL, &tg->uclamp[UCLAMP_MIN], UCLAMP_MIN, min_value);
+
/* Update effective clamps to track the most restrictive value */
- cpu_util_update_hier(css, UCLAMP_MIN, min_value);
+ cpu_util_update_hier(css, UCLAMP_MIN, tg->uclamp[UCLAMP_MIN].bucket_id,
+ min_value);
out:
rcu_read_unlock();
+ mutex_unlock(&uclamp_mutex);
return ret;
}
@@ -7222,6 +7245,7 @@ static int cpu_util_max_write_u64(struct cgroup_subsys_state *css,
if (max_value > SCHED_CAPACITY_SCALE)
return -ERANGE;
+ mutex_lock(&uclamp_mutex);
rcu_read_lock();
tg = css_tg(css);
@@ -7232,11 +7256,16 @@ static int cpu_util_max_write_u64(struct cgroup_subsys_state *css,
goto out;
}
+ /* Update TG's reference count */
+ uclamp_bucket_inc(NULL, &tg->uclamp[UCLAMP_MAX], UCLAMP_MAX, max_value);
+
/* Update effective clamps to track the most restrictive value */
- cpu_util_update_hier(css, UCLAMP_MAX, max_value);
+ cpu_util_update_hier(css, UCLAMP_MAX, tg->uclamp[UCLAMP_MAX].bucket_id,
+ max_value);
out:
rcu_read_unlock();
+ mutex_unlock(&uclamp_mutex);
return ret;
}
--
2.19.2
next prev parent reply other threads:[~2019-01-15 10:16 UTC|newest]
Thread overview: 89+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-15 10:14 [PATCH v6 00/16] Add utilization clamping support Patrick Bellasi
2019-01-15 10:14 ` [PATCH v6 01/16] sched/core: Allow sched_setattr() to use the current policy Patrick Bellasi
2019-01-25 13:56 ` Alessio Balsini
2019-01-15 10:14 ` [PATCH v6 02/16] sched/core: uclamp: Extend sched_setattr() to support utilization clamping Patrick Bellasi
2019-01-15 10:15 ` [PATCH v6 03/16] sched/core: uclamp: Map TASK's clamp values into CPU's clamp buckets Patrick Bellasi
2019-01-21 10:15 ` Peter Zijlstra
2019-01-21 12:27 ` Patrick Bellasi
2019-01-21 12:51 ` Peter Zijlstra
2019-01-21 15:05 ` Peter Zijlstra
2019-01-21 15:34 ` Patrick Bellasi
2019-01-15 10:15 ` [PATCH v6 04/16] sched/core: uclamp: Add CPU's clamp buckets refcounting Patrick Bellasi
2019-01-21 14:59 ` Peter Zijlstra
2019-01-21 15:23 ` Patrick Bellasi
2019-01-21 16:12 ` Peter Zijlstra
2019-01-21 16:33 ` Patrick Bellasi
2019-01-22 9:45 ` Peter Zijlstra
2019-01-22 10:31 ` Patrick Bellasi
2019-01-21 15:17 ` Peter Zijlstra
2019-01-21 15:54 ` Patrick Bellasi
2019-01-22 10:03 ` Peter Zijlstra
2019-01-22 10:53 ` Patrick Bellasi
2019-01-15 10:15 ` [PATCH v6 05/16] sched/core: uclamp: Update CPU's refcount on clamp changes Patrick Bellasi
2019-01-21 15:33 ` Peter Zijlstra
2019-01-21 15:44 ` Patrick Bellasi
2019-01-22 9:37 ` Peter Zijlstra
2019-01-22 10:43 ` Patrick Bellasi
2019-01-22 13:28 ` Peter Zijlstra
2019-01-22 14:01 ` Patrick Bellasi
2019-01-22 14:57 ` Peter Zijlstra
2019-01-22 15:33 ` Patrick Bellasi
2019-01-23 9:16 ` Peter Zijlstra
2019-01-23 14:14 ` Patrick Bellasi
2019-01-23 18:59 ` Peter Zijlstra
2019-01-24 11:21 ` Patrick Bellasi
2019-01-24 12:38 ` Peter Zijlstra
2019-01-15 10:15 ` [PATCH v6 06/16] sched/core: uclamp: Enforce last task UCLAMP_MAX Patrick Bellasi
2019-01-15 10:15 ` [PATCH v6 07/16] sched/core: uclamp: Add system default clamps Patrick Bellasi
2019-01-22 13:56 ` Peter Zijlstra
2019-01-22 14:43 ` Patrick Bellasi
2019-01-22 15:13 ` Peter Zijlstra
2019-01-22 15:41 ` Patrick Bellasi
2019-01-23 9:22 ` Peter Zijlstra
2019-01-23 14:19 ` Patrick Bellasi
2019-01-23 19:10 ` Peter Zijlstra
2019-01-15 10:15 ` [PATCH v6 08/16] sched/cpufreq: uclamp: Add utilization clamping for FAIR tasks Patrick Bellasi
2019-01-22 10:37 ` Rafael J. Wysocki
2019-01-22 11:02 ` Patrick Bellasi
2019-01-22 11:04 ` Rafael J. Wysocki
2019-01-22 11:27 ` Patrick Bellasi
2019-01-22 15:21 ` Peter Zijlstra
2019-01-22 15:45 ` Patrick Bellasi
2019-01-22 17:13 ` Peter Zijlstra
2019-01-22 18:18 ` Patrick Bellasi
2019-01-23 9:52 ` Peter Zijlstra
2019-01-23 14:24 ` Patrick Bellasi
2019-01-15 10:15 ` [PATCH v6 09/16] sched/cpufreq: uclamp: Add utilization clamping for RT tasks Patrick Bellasi
2019-01-22 12:30 ` Quentin Perret
2019-01-22 12:37 ` Patrick Bellasi
2019-01-23 10:28 ` Peter Zijlstra
2019-01-23 14:33 ` Patrick Bellasi
2019-01-23 10:49 ` Peter Zijlstra
2019-01-23 14:40 ` Patrick Bellasi
2019-01-23 20:11 ` Peter Zijlstra
2019-01-24 12:30 ` Patrick Bellasi
2019-01-24 12:38 ` Patrick Bellasi
2019-01-24 15:12 ` Peter Zijlstra
2019-01-24 16:00 ` Patrick Bellasi
2019-01-24 15:31 ` Peter Zijlstra
2019-01-24 16:14 ` Patrick Bellasi
2019-01-24 15:33 ` Peter Zijlstra
2019-01-24 15:15 ` Peter Zijlstra
2019-01-24 16:05 ` Patrick Bellasi
2019-01-15 10:15 ` [PATCH v6 10/16] sched/core: Add uclamp_util_with() Patrick Bellasi
2019-01-23 13:33 ` Peter Zijlstra
2019-01-23 14:51 ` Patrick Bellasi
2019-01-23 19:22 ` Peter Zijlstra
2019-01-15 10:15 ` [PATCH v6 11/16] sched/fair: Add uclamp support to energy_compute() Patrick Bellasi
2019-01-22 12:13 ` Quentin Perret
2019-01-22 12:45 ` Patrick Bellasi
2019-01-22 13:29 ` Quentin Perret
2019-01-22 14:26 ` Patrick Bellasi
2019-01-22 14:39 ` Quentin Perret
2019-01-22 15:01 ` Patrick Bellasi
2019-01-22 15:14 ` Quentin Perret
2019-01-15 10:15 ` [PATCH v6 12/16] sched/core: uclamp: Extend CPU's cgroup controller Patrick Bellasi
2019-01-15 10:15 ` [PATCH v6 13/16] sched/core: uclamp: Propagate parent clamps Patrick Bellasi
2019-01-15 10:15 ` Patrick Bellasi [this message]
2019-01-15 10:15 ` [PATCH v6 15/16] sched/core: uclamp: Use TG's clamps to restrict TASK's clamps Patrick Bellasi
2019-01-15 10:15 ` [PATCH v6 16/16] sched/core: uclamp: Update CPU's refcount on TG's clamp changes Patrick Bellasi
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