From: Viresh Kumar <viresh.kumar@linaro.org>
To: Rafael Wysocki <rjw@rjwysocki.net>,
Ben Segall <bsegall@google.com>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Ingo Molnar <mingo@redhat.com>,
Juri Lelli <juri.lelli@redhat.com>, Mel Gorman <mgorman@suse.de>,
Peter Zijlstra <peterz@infradead.org>,
Steven Rostedt <rostedt@goodmis.org>,
Vincent Guittot <vincent.guittot@linaro.org>,
Viresh Kumar <viresh.kumar@linaro.org>
Cc: linux-pm@vger.kernel.org, Lukasz Luba <lukasz.luba@arm.com>,
cristian.marussi@arm.com, sudeep.holla@arm.com,
linux-kernel@vger.kernel.org
Subject: [PATCH V3 0/5] cpufreq: Record stats with fast-switching
Date: Mon, 5 Oct 2020 13:26:00 +0530 [thread overview]
Message-ID: <cover.1601884370.git.viresh.kumar@linaro.org> (raw)
Hi,
We disabled recording cpufreq stats when fast switching was introduced
to the cpufreq core as the cpufreq stats required to take a spinlock and
that can't be allowed (for performance reasons) on scheduler's hot path.
Here is an attempt to get rid of the lock and bring back the support.
V2->V3:
- Use READ/WRITE_ONCE() for reset-time as well.
- Use unlikely for few conditionals in the hot path.
- Better changelogs.
- Rebase changes.
V1-V2:
- Use READ_ONCE/WRITE_ONCE instead of atomic in the first patch.
--
Viresh
Viresh Kumar (5):
cpufreq: stats: Defer stats update to
cpufreq_stats_record_transition()
cpufreq: stats: Remove locking
cpufreq: stats: Mark few conditionals with unlikely()
cpufreq: stats: Enable stats for fast-switch as well
cpufreq: Move traces and update to policy->cur to cpufreq core
drivers/cpufreq/cpufreq.c | 11 ++++
drivers/cpufreq/cpufreq_stats.c | 89 ++++++++++++++++++++------------
kernel/sched/cpufreq_schedutil.c | 12 +----
3 files changed, 69 insertions(+), 43 deletions(-)
--
2.25.0.rc1.19.g042ed3e048af
next reply other threads:[~2020-10-05 7:56 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-05 7:56 Viresh Kumar [this message]
2020-10-05 7:56 ` [PATCH V3 1/5] cpufreq: stats: Defer stats update to cpufreq_stats_record_transition() Viresh Kumar
2020-10-05 7:56 ` [PATCH V3 2/5] cpufreq: stats: Remove locking Viresh Kumar
2020-10-05 7:56 ` [PATCH V3 3/5] cpufreq: stats: Mark few conditionals with unlikely() Viresh Kumar
2020-10-05 7:56 ` [PATCH V3 4/5] cpufreq: stats: Enable stats for fast-switch as well Viresh Kumar
2020-10-05 7:56 ` [PATCH V3 5/5] cpufreq: Move traces and update to policy->cur to cpufreq core Viresh Kumar
2020-10-05 13:25 ` [PATCH V3 0/5] cpufreq: Record stats with fast-switching Rafael J. Wysocki
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