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 v9 15/16] sched/core: uclamp: Use TG's clamps to restrict TASK's clamps
Date: Wed, 15 May 2019 10:44:58 +0100 [thread overview]
Message-ID: <20190515094459.10317-16-patrick.bellasi@arm.com> (raw)
In-Reply-To: <20190515094459.10317-1-patrick.bellasi@arm.com>
When a task specific clamp value is configured via sched_setattr(2),
this value is accounted in the corresponding clamp bucket every time the
task is {en,de}qeued. However, when cgroups are also in use, the task
specific clamp values could be restricted by the task_group (TG)
clamp values.
Update uclamp_cpu_inc() to aggregate task and TG clamp values. Every
time a task is enqueued, it's accounted in the clamp_bucket defining the
smaller clamp between the task specific value and its TG effective
value. This allows to:
1. ensure cgroup clamps are always used to restrict task specific
requests, i.e. boosted only up to the effective granted value or
clamped at least to a certain value
2. implement a "nice-like" policy, where tasks are still allowed to
request less then what enforced by their current TG
This mimics what already happens for a task's CPU affinity mask when the
task is also in a cpuset, i.e. cgroup attributes are always used to
restrict per-task attributes.
Do this by exploiting the concept of "effective" clamp, which is already
used by a TG to track parent enforced restrictions.
Apply task group clamp restrictions only to tasks belonging to a child
group. While, for tasks in the root group or in an autogroup, only
system defaults are enforced.
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>
---
kernel/sched/core.c | 28 +++++++++++++++++++++++++++-
1 file changed, 27 insertions(+), 1 deletion(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index bd96a977ed07..354d925a6ba8 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -861,16 +861,42 @@ unsigned int uclamp_rq_max_value(struct rq *rq, unsigned int clamp_id,
return uclamp_idle_value(rq, clamp_id, clamp_value);
}
+static inline struct uclamp_se
+uclamp_tg_restrict(struct task_struct *p, unsigned int clamp_id)
+{
+ struct uclamp_se uc_req = p->uclamp_req[clamp_id];
+#ifdef CONFIG_UCLAMP_TASK_GROUP
+ struct uclamp_se uc_max;
+
+ /*
+ * Tasks in autogroups or root task group will be
+ * restricted by system defaults.
+ */
+ if (task_group_is_autogroup(task_group(p)))
+ return uc_req;
+ if (task_group(p) == &root_task_group)
+ return uc_req;
+
+ uc_max = task_group(p)->uclamp[clamp_id];
+ if (uc_req.value > uc_max.value || !uc_req.user_defined)
+ return uc_max;
+#endif
+
+ return uc_req;
+}
+
/*
* The effective clamp bucket index of a task depends on, by increasing
* priority:
* - the task specific clamp value, when explicitly requested from userspace
+ * - the task group effective clamp value, for tasks not either in the root
+ * group or in an autogroup
* - the system default clamp value, defined by the sysadmin
*/
static inline struct uclamp_se
uclamp_eff_get(struct task_struct *p, unsigned int clamp_id)
{
- struct uclamp_se uc_req = p->uclamp_req[clamp_id];
+ struct uclamp_se uc_req = uclamp_tg_restrict(p, clamp_id);
struct uclamp_se uc_max = uclamp_default[clamp_id];
/* System default restrictions always apply */
--
2.21.0
next prev parent reply other threads:[~2019-05-15 9:46 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-15 9:44 [PATCH v9 00/16] Add utilization clamping support Patrick Bellasi
2019-05-15 9:44 ` [PATCH v9 01/16] sched/core: uclamp: Add CPU's clamp buckets refcounting Patrick Bellasi
2019-05-15 9:44 ` [PATCH v9 02/16] sched/core: uclamp: Add bucket local max tracking Patrick Bellasi
2019-05-15 9:44 ` [PATCH v9 03/16] sched/core: uclamp: Enforce last task's UCLAMP_MAX Patrick Bellasi
2019-05-15 9:44 ` [PATCH v9 04/16] sched/core: uclamp: Add system default clamps Patrick Bellasi
2019-05-15 9:44 ` [PATCH v9 05/16] sched/core: Allow sched_setattr() to use the current policy Patrick Bellasi
2019-05-15 9:44 ` [PATCH v9 06/16] sched/core: uclamp: Extend sched_setattr() to support utilization clamping Patrick Bellasi
2019-05-15 9:44 ` [PATCH v9 07/16] sched/core: uclamp: Reset uclamp values on RESET_ON_FORK Patrick Bellasi
2019-05-15 9:44 ` [PATCH v9 08/16] sched/core: uclamp: Set default clamps for RT tasks Patrick Bellasi
2019-05-15 9:44 ` [PATCH v9 09/16] sched/cpufreq: uclamp: Add clamps for FAIR and " Patrick Bellasi
2019-05-15 9:44 ` [PATCH v9 10/16] sched/core: uclamp: Add uclamp_util_with() Patrick Bellasi
2019-05-15 9:44 ` [PATCH v9 11/16] sched/fair: uclamp: Add uclamp support to energy_compute() Patrick Bellasi
2019-05-15 9:44 ` [PATCH v9 12/16] sched/core: uclamp: Extend CPU's cgroup controller Patrick Bellasi
2019-05-31 15:35 ` Tejun Heo
2019-06-03 12:24 ` Patrick Bellasi
2019-06-03 12:27 ` Patrick Bellasi
2019-06-05 14:03 ` Tejun Heo
2019-06-05 14:39 ` Patrick Bellasi
2019-06-05 14:44 ` Tejun Heo
2019-06-05 15:37 ` Patrick Bellasi
2019-06-05 15:39 ` Tejun Heo
2019-06-03 12:29 ` Patrick Bellasi
2019-06-05 14:09 ` Tejun Heo
2019-06-05 15:06 ` Patrick Bellasi
2019-06-05 15:27 ` Tejun Heo
2019-05-15 9:44 ` [PATCH v9 13/16] sched/core: uclamp: Propagate parent clamps Patrick Bellasi
2019-05-15 9:44 ` [PATCH v9 14/16] sched/core: uclamp: Propagate system defaults to root group Patrick Bellasi
2019-05-15 9:44 ` Patrick Bellasi [this message]
2019-05-15 9:44 ` [PATCH v9 16/16] sched/core: uclamp: Update CPU's refcount on TG's clamp changes Patrick Bellasi
2019-05-30 10:15 ` [PATCH v9 00/16] Add utilization clamping support Patrick Bellasi
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190515094459.10317-16-patrick.bellasi@arm.com \
--to=patrick.bellasi@arm.com \
--cc=dietmar.eggemann@arm.com \
--cc=joelaf@google.com \
--cc=juri.lelli@redhat.com \
--cc=linux-api@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pm@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=morten.rasmussen@arm.com \
--cc=peterz@infradead.org \
--cc=pjt@google.com \
--cc=quentin.perret@arm.com \
--cc=rafael.j.wysocki@intel.com \
--cc=smuckle@google.com \
--cc=surenb@google.com \
--cc=tj@kernel.org \
--cc=tkjos@google.com \
--cc=vincent.guittot@linaro.org \
--cc=viresh.kumar@linaro.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).