Messages in this thread | | | Date | Mon, 24 Jul 2017 14:27:45 +0530 | From | Viresh Kumar <> | Subject | Re: [PATCH v7 1/2] cpufreq: schedutil: Make iowait boost more energy efficient |
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On 23-07-17, 08:54, Joel Fernandes wrote: > Currently the iowait_boost feature in schedutil makes the frequency go to max > on iowait wakeups. This feature was added to handle a case that Peter > described where the throughput of operations involving continuous I/O requests > [1] is reduced due to running at a lower frequency, however the lower > throughput itself causes utilization to be low and hence causing frequency to > be low hence its "stuck". > > Instead of going to max, its also possible to achieve the same effect by > ramping up to max if there are repeated in_iowait wakeups happening. This patch > is an attempt to do that. We start from a lower frequency (policy->min) > and double the boost for every consecutive iowait update until we reach the > maximum iowait boost frequency (iowait_boost_max). > > I ran a synthetic test (continuous O_DIRECT writes in a loop) on an x86 machine > with intel_pstate in passive mode using schedutil. In this test the iowait_boost > value ramped from 800MHz to 4GHz in 60ms. The patch achieves the desired improved > throughput as the existing behavior. > > [1] https://patchwork.kernel.org/patch/9735885/ > > Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> > Cc: Len Brown <lenb@kernel.org> > Cc: Rafael J. Wysocki <rjw@rjwysocki.net> > Cc: Viresh Kumar <viresh.kumar@linaro.org> > Cc: Ingo Molnar <mingo@redhat.com> > Cc: Peter Zijlstra <peterz@infradead.org> > Suggested-by: Peter Zijlstra <peterz@infradead.org> > Suggested-by: Viresh Kumar <viresh.kumar@linaro.org> > Signed-off-by: Joel Fernandes <joelaf@google.com> > --- > kernel/sched/cpufreq_schedutil.c | 38 ++++++++++++++++++++++++++++++++------ > 1 file changed, 32 insertions(+), 6 deletions(-)
You Send V7 [1-2]/2 twice, Are they different ?
For both the patches:
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
-- viresh
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