lkml.org 
[lkml]   [2017]   [Jul]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v7 1/2] cpufreq: schedutil: Make iowait boost more energy efficient
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

\
 
 \ /
  Last update: 2017-07-24 10:57    [W:0.368 / U:0.732 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site