On Monday, July 24, 2017 11:37:58 AM Joel Fernandes wrote: > On Mon, Jul 24, 2017 at 1:57 AM, Viresh Kumar <[email protected]> wrote: > > 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 ? > > No they are the same. Rafael suggested reposting it with linux-pm in > CC I just resent it. > > > > > For both the patches: > > > > Acked-by: Viresh Kumar <[email protected]> > > Thanks!
Applied, thanks!
