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! -Joel
