From: Lukasz Luba <lukasz.luba@arm.com>
To: linux-kernel@vger.kernel.org
Cc: linux-pm@vger.kernel.org, peterz@infradead.org,
rjw@rjwysocki.net, viresh.kumar@linaro.org,
vincent.guittot@linaro.org, qperret@google.com,
dietmar.eggemann@arm.com, vincent.donnefort@arm.com,
lukasz.luba@arm.com, Beata.Michalska@arm.com, mingo@redhat.com,
juri.lelli@redhat.com, rostedt@goodmis.org, segall@google.com,
mgorman@suse.de, bristot@redhat.com, thara.gopinath@linaro.org,
amit.kachhap@gmail.com, amitk@kernel.org, rui.zhang@intel.com,
daniel.lezcano@linaro.org
Subject: [PATCH v3 0/3] Add allowed CPU capacity knowledge to EAS
Date: Thu, 10 Jun 2021 16:03:21 +0100 [thread overview]
Message-ID: <20210610150324.22919-1-lukasz.luba@arm.com> (raw)
Hi all,
The patch set v3 aims to add knowledge about reduced CPU capacity
into the Energy Model (EM) and Energy Aware Scheduler (EAS). Currently the
issue is that SchedUtil CPU frequency and EM frequency are not aligned,
when there is a CPU thermal capping. This causes an estimation error.
This patch set provides the information about allowed CPU capacity
into the EM (thanks to thermal pressure information). This improves the
energy estimation. More info about this mechanism can be found in the
patches comments.
There is a new patch 1/3 in this v3, addressing an issue triggered for
hotplugged out CPU. The offline CPUs don't have proper value stored by
thermal framework in their per-cpu thermal_pressure. Thus, the thermal
pressure geometric series machinery reads 'stale' value when the CPU
is back online. The patch fixes it, so all mechanisms like
load balance, not only EAS, would have more accurate CPU capacity
information for those 'returning online' CPUs. I've added also related
cpu cooling maintainers to the CC of this patch set.
Changelog:
v3:
- switched to 'raw' per-cpu thermal pressure instead of thermal pressure
geometric series signal, since it more suited for purpose of
this use case: predicting SchedUtil frequency (Vincent, Dietmar)
- added more comment in the patch 2/3 header for use case when thermal
capping might be applied even the CPUs are not over-utilized
(Dietmar)
- added ACK tag from Rafael for SchedUtil part
- added a fix patch for offline CPUs in cpufreq_cooling and per-cpu
thermal_pressure missing update
v2 [2]:
- clamp the returned value from effective_cpu_util() and avoid irq
util scaling issues (Quentin)
v1 is available at [1]
Regards,
Lukasz
[1] https://lore.kernel.org/linux-pm/20210602135609.10867-1-lukasz.luba@arm.com/
[2] https://lore.kernel.org/lkml/20210604080954.13915-1-lukasz.luba@arm.com/
Lukasz Luba (3):
thermal: cpufreq_cooling: Update also offline CPUs per-cpu
thermal_pressure
sched/fair: Take thermal pressure into account while estimating energy
sched/cpufreq: Consider reduced CPU capacity in energy calculation
drivers/thermal/cpufreq_cooling.c | 2 +-
include/linux/energy_model.h | 16 +++++++++++++---
include/linux/sched/cpufreq.h | 2 +-
kernel/sched/cpufreq_schedutil.c | 1 +
kernel/sched/fair.c | 14 ++++++++++----
5 files changed, 26 insertions(+), 9 deletions(-)
--
2.17.1
next reply other threads:[~2021-06-10 15:03 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-10 15:03 Lukasz Luba [this message]
2021-06-10 15:03 ` [PATCH v3 1/3] thermal: cpufreq_cooling: Update also offline CPUs per-cpu thermal_pressure Lukasz Luba
2021-06-14 10:12 ` Viresh Kumar
2021-06-14 10:21 ` Lukasz Luba
2021-06-10 15:03 ` [PATCH v3 2/3] sched/fair: Take thermal pressure into account while estimating energy Lukasz Luba
2021-06-14 15:29 ` Lukasz Luba
2021-06-14 15:48 ` Vincent Guittot
2021-06-14 16:03 ` Vincent Guittot
2021-06-14 18:22 ` Lukasz Luba
2021-06-10 15:03 ` [PATCH v3 3/3] sched/cpufreq: Consider reduced CPU capacity in energy calculation 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=20210610150324.22919-1-lukasz.luba@arm.com \
--to=lukasz.luba@arm.com \
--cc=Beata.Michalska@arm.com \
--cc=amit.kachhap@gmail.com \
--cc=amitk@kernel.org \
--cc=bristot@redhat.com \
--cc=daniel.lezcano@linaro.org \
--cc=dietmar.eggemann@arm.com \
--cc=juri.lelli@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pm@vger.kernel.org \
--cc=mgorman@suse.de \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
--cc=qperret@google.com \
--cc=rjw@rjwysocki.net \
--cc=rostedt@goodmis.org \
--cc=rui.zhang@intel.com \
--cc=segall@google.com \
--cc=thara.gopinath@linaro.org \
--cc=vincent.donnefort@arm.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.