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 <[email protected]>
> Cc: Len Brown <[email protected]>
> Cc: Rafael J. Wysocki <[email protected]>
> Cc: Viresh Kumar <[email protected]>
> Cc: Ingo Molnar <[email protected]>
> Cc: Peter Zijlstra <[email protected]>
> Suggested-by: Peter Zijlstra <[email protected]>
> Suggested-by: Viresh Kumar <[email protected]>
> Signed-off-by: Joel Fernandes <[email protected]>
> ---
>  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 <[email protected]>

-- 
viresh

Reply via email to