From: Thara Gopinath <thara.gopinath@linaro.org>
To: linux-kernel@vger.kernel.org, mingo@redhat.com,
peterz@infradead.org, rui.zhang@intel.com
Cc: gregkh@linuxfoundation.org, rafael@kernel.org,
amit.kachhap@gmail.com, viresh.kumar@linaro.org,
javi.merino@kernel.org, edubezval@gmail.com,
daniel.lezcano@linaro.org, linux-pm@vger.kernel.org,
quentin.perret@arm.com, ionela.voinescu@arm.com,
vincent.guittot@linaro.org
Subject: [RFC PATCH 3/7] sched: Add infrastructure to store and update instantaneous thermal pressure
Date: Tue, 9 Oct 2018 12:24:58 -0400 [thread overview]
Message-ID: <1539102302-9057-4-git-send-email-thara.gopinath@linaro.org> (raw)
In-Reply-To: <1539102302-9057-1-git-send-email-thara.gopinath@linaro.org>
Add thermal.c and thermal.h files that provides interface
APIs to initialize, update/average, track, accumulate and decay
thermal pressure per cpu basis. A per cpu structure max_capacity_info is
introduced to keep track of instantaneous per cpu thermal pressure.
Thermal pressure the delta between max_capacity and cap_capacity.
API update_periodic_maxcap is called for periodic accumulate and decay
of the thermal pressure. It is to to be called from a periodic tick
function. The API calculates the delta between max_capacity and
cap_capacity and passes on the delta to update_thermal_avg to do the
necessary accumulate, decay and average. update_maxcap_capacity is for
the system to update the thermal pressure by updating cap_capacity.
Considering, update_periodic_maxcap reads cap_capacity and
update_maxcap_capacity writes into cap_capacity, one can argue for
some sort of locking mechanism to avoid a stale value.
But considering update_periodic_maxcap can be called from a system
critical path like scheduler tick function, a locking mechanism is not
ideal. This means that possibly for 1 tick period the value used to
calculate average thermal pressure for a cpu can be stale.
Signed-off-by: Thara Gopinath <thara.gopinath@linaro.org>
---
include/linux/sched.h | 14 +++++++++++
kernel/sched/Makefile | 2 +-
kernel/sched/thermal.c | 66 ++++++++++++++++++++++++++++++++++++++++++++++++++
kernel/sched/thermal.h | 13 ++++++++++
4 files changed, 94 insertions(+), 1 deletion(-)
create mode 100644 kernel/sched/thermal.c
create mode 100644 kernel/sched/thermal.h
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 977cb57..931b76d 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1891,3 +1891,17 @@ static inline void rseq_syscall(struct pt_regs *regs)
#endif
#endif
+
+#ifdef CONFIG_SMP
+void update_maxcap_capacity(int cpu, u64 capacity);
+
+void populate_max_capacity_info(void);
+#else
+static inline void update_maxcap_capacity(int cpu, u64 capacity)
+{
+}
+
+static inline void populate_max_capacity_info(void)
+{
+}
+#endif
diff --git a/kernel/sched/Makefile b/kernel/sched/Makefile
index 7fe1834..232a0cf 100644
--- a/kernel/sched/Makefile
+++ b/kernel/sched/Makefile
@@ -20,7 +20,7 @@ obj-y += core.o loadavg.o clock.o cputime.o
obj-y += idle.o fair.o rt.o deadline.o
obj-y += wait.o wait_bit.o swait.o completion.o
-obj-$(CONFIG_SMP) += cpupri.o cpudeadline.o topology.o stop_task.o pelt.o
+obj-$(CONFIG_SMP) += cpupri.o cpudeadline.o topology.o stop_task.o pelt.o thermal.o
obj-$(CONFIG_SCHED_AUTOGROUP) += autogroup.o
obj-$(CONFIG_SCHEDSTATS) += stats.o
obj-$(CONFIG_SCHED_DEBUG) += debug.o
diff --git a/kernel/sched/thermal.c b/kernel/sched/thermal.c
new file mode 100644
index 0000000..dd8300d
--- /dev/null
+++ b/kernel/sched/thermal.c
@@ -0,0 +1,66 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Sceduler Thermal Interactions
+ *
+ * Copyright (C) 2018 Linaro, Inc., Thara Gopinath <thara.gopinath@linaro.org>
+ */
+
+#include <linux/sched.h>
+#include "sched.h"
+#include "pelt.h"
+#include "thermal.h"
+
+struct max_capacity_info {
+ unsigned long max_capacity;
+ unsigned long cap_capacity;
+};
+
+static DEFINE_PER_CPU(struct max_capacity_info, max_cap);
+
+void update_maxcap_capacity(int cpu, u64 capacity)
+{
+ struct max_capacity_info *__max_cap;
+ u64 __capacity;
+
+ __max_cap = (&per_cpu(max_cap, cpu));
+ if (!__max_cap) {
+ pr_err("no max_capacity_info structure for cpu %d\n", cpu);
+ return;
+ }
+
+ /* Normalize the capacity */
+ __capacity = (capacity * arch_scale_cpu_capacity(NULL, cpu)) >>
+ SCHED_CAPACITY_SHIFT;
+ pr_debug("updating cpu%d capped capacity from %ld to %ld\n", cpu, __max_cap->cap_capacity, __capacity);
+
+ __max_cap->cap_capacity = __capacity;
+}
+
+void populate_max_capacity_info(void)
+{
+ struct max_capacity_info *__max_cap;
+ u64 capacity;
+ int cpu;
+
+
+ for_each_possible_cpu(cpu) {
+ __max_cap = (&per_cpu(max_cap, cpu));
+ if (!__max_cap)
+ continue;
+ capacity = arch_scale_cpu_capacity(NULL, cpu);
+ __max_cap->max_capacity = __max_cap->cap_capacity = capacity;
+ pr_debug("cpu %d max capacity set to %ld\n", cpu, __max_cap->max_capacity);
+ }
+}
+
+void update_periodic_maxcap(struct rq *rq)
+{
+ struct max_capacity_info *__max_cap = (&per_cpu(max_cap, cpu_of(rq)));
+ unsigned long delta;
+
+ if (!__max_cap)
+ return;
+
+ delta = __max_cap->max_capacity - __max_cap->cap_capacity;
+ update_thermal_avg(rq_clock_task(rq), rq, delta);
+}
diff --git a/kernel/sched/thermal.h b/kernel/sched/thermal.h
new file mode 100644
index 0000000..20a0270
--- /dev/null
+++ b/kernel/sched/thermal.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Scheduler thermal interaction internal methods.
+ */
+
+#ifdef CONFIG_SMP
+void update_periodic_maxcap(struct rq *rq);
+
+#else
+static inline void update_periodic_maxcap(struct rq *rq)
+{
+}
+#endif
--
2.1.4
next prev parent reply other threads:[~2018-10-09 16:25 UTC|newest]
Thread overview: 67+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20181009162509epcas1p4fdd2e23039caa24586a4a52c6d2e7336@epcas1p4.samsung.com>
2018-10-09 16:24 ` [RFC PATCH 0/7] Introduce thermal pressure Thara Gopinath
2018-10-09 16:24 ` [RFC PATCH 1/7] sched/pelt.c: Add option to make load and util calculations frequency invariant Thara Gopinath
2018-10-09 16:24 ` [RFC PATCH 2/7] sched/pelt.c: Add support to track thermal pressure Thara Gopinath
2018-10-09 16:24 ` Thara Gopinath [this message]
2018-10-09 16:24 ` [RFC PATCH 4/7] sched: Initialize per cpu thermal pressure structure Thara Gopinath
2018-10-09 16:25 ` [RFC PATCH 5/7] sched/fair: Enable CFS periodic tick to update thermal pressure Thara Gopinath
2018-12-04 15:43 ` Vincent Guittot
2018-10-09 16:25 ` [RFC PATCH 6/7] sched/fair: update cpu_capcity to reflect " Thara Gopinath
2018-10-10 5:57 ` Javi Merino
2018-10-10 14:22 ` Thara Gopinath
2018-10-09 16:25 ` [RFC PATCH 7/7] thermal/cpu-cooling: Update thermal pressure in case of a maximum frequency capping Thara Gopinath
2018-10-10 5:44 ` [RFC PATCH 0/7] Introduce thermal pressure Javi Merino
2018-10-10 14:15 ` Thara Gopinath
2018-10-10 6:17 ` Ingo Molnar
2018-10-10 8:29 ` Quentin Perret
2018-10-10 8:50 ` Vincent Guittot
2018-10-10 9:55 ` Quentin Perret
2018-10-10 10:14 ` Vincent Guittot
2018-10-10 10:36 ` Quentin Perret
2018-10-10 12:04 ` Vincent Guittot
2018-10-10 12:23 ` Juri Lelli
2018-10-10 12:34 ` Vincent Guittot
2018-10-10 12:50 ` Juri Lelli
2018-10-10 13:08 ` Vincent Guittot
2018-10-10 13:34 ` Juri Lelli
2018-10-10 13:38 ` Vincent Guittot
2018-10-10 17:08 ` Thara Gopinath
2018-10-10 13:11 ` Quentin Perret
2018-10-10 13:05 ` Quentin Perret
2018-10-10 13:27 ` Vincent Guittot
2018-10-10 13:47 ` Quentin Perret
2018-10-10 15:19 ` Vincent Guittot
2018-10-10 16:15 ` Ionela Voinescu
2018-10-10 17:03 ` Thara Gopinath
2018-10-10 15:43 ` Thara Gopinath
2018-10-16 7:33 ` Ingo Molnar
2018-10-16 9:28 ` Lukasz Luba
2018-10-17 16:21 ` Thara Gopinath
2018-10-18 6:48 ` Ingo Molnar
2018-10-18 7:08 ` Rafael J. Wysocki
2018-10-18 7:50 ` Ingo Molnar
2018-10-18 8:14 ` Rafael J. Wysocki
2018-10-18 9:35 ` [PATCH 1/2] sched/cpufreq: Reorganize the cpufreq files Daniel Lezcano
2018-10-18 9:35 ` [PATCH 2/2] sched/cpufreq: Add the SPDX tags Daniel Lezcano
2018-10-18 9:42 ` [PATCH 1/2] sched/cpufreq: Reorganize the cpufreq files Rafael J. Wysocki
2018-10-18 9:54 ` Daniel Lezcano
2018-10-18 10:06 ` Rafael J. Wysocki
2018-10-18 10:13 ` Daniel Lezcano
2018-10-18 9:45 ` Daniel Lezcano
2018-10-19 5:24 ` kbuild test robot
2018-10-19 5:52 ` kbuild test robot
2018-10-18 9:44 ` [PATCH V2 " Daniel Lezcano
2018-10-18 9:44 ` [PATCH V2 2/2] sched/cpufreq: Add the SPDX tags Daniel Lezcano
2018-10-18 16:17 ` [RFC PATCH 0/7] Introduce thermal pressure Thara Gopinath
2018-10-19 8:02 ` Ingo Molnar
2018-10-19 11:29 ` Valentin Schneider
2018-10-10 15:35 ` Lukasz Luba
2018-10-10 16:54 ` Daniel Lezcano
2018-10-11 7:35 ` Lukasz Luba
2018-10-11 8:23 ` Daniel Lezcano
2018-10-12 9:37 ` Lukasz Luba
2018-10-10 17:30 ` Thara Gopinath
2018-10-11 11:10 ` Lukasz Luba
2018-10-16 17:11 ` Vincent Guittot
2018-10-17 16:24 ` Thara Gopinath
2018-10-18 8:00 ` Lukasz Luba
2018-10-18 8:12 ` Lukasz Luba
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=1539102302-9057-4-git-send-email-thara.gopinath@linaro.org \
--to=thara.gopinath@linaro.org \
--cc=amit.kachhap@gmail.com \
--cc=daniel.lezcano@linaro.org \
--cc=edubezval@gmail.com \
--cc=gregkh@linuxfoundation.org \
--cc=ionela.voinescu@arm.com \
--cc=javi.merino@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pm@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
--cc=quentin.perret@arm.com \
--cc=rafael@kernel.org \
--cc=rui.zhang@intel.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).