On 22-Dec 13:07, Juri Lelli wrote: > Hi Peter, > > On 22/12/17 12:46, Peter Zijlstra wrote: > > On Fri, Dec 22, 2017 at 11:02:06AM +0000, Patrick Bellasi wrote: > > > > @@ -315,8 +315,8 @@ static unsigned int sugov_next_freq_shared(struct > > > > sugov_cpu *sg_cpu, u64 time) > > > > unsigned long j_util, j_max; > > > > s64 delta_ns; > > > > > > > > - if (j_sg_cpu != sg_cpu) > > > > - sugov_get_util(j_sg_cpu); > > > > + if (idle_cpu(j)) > > > > + continue; > > > > > > That should work to skip IDLE CPUs... however I'm missing where now we > > > get the sugov_get_util(j_sg_cpu) for active CPUs. It has been moved > > > somewhere else I guess... > > > > No, I'm just an idiot... lemme fix that. > > > > > Moreover, that way don't we completely disregard CFS blocked load for > > > IDLE CPUs... as well as DL reserved utilization, which should be > > > released only at the 0-lag time? > > > > I was thinking that since dl is a 'global' scheduler the reservation > > would be too and thus the freq just needs a single CPU to be observed; > > but I suppose there's nothing stopping anybody from splitting a clock > > domain down the middle scheduling wise. So yes, good point. > > Also, for CFS current behaviour is to start ignoring contributions after > TICK_NS. It seems that your change might introduce regressions?
Good point, an energy regression I guess you mean... I think that check is already gone for CFS in the current PeterZ tree. It seems we use TICK_NS just for the reset of iowait_boost, isn't it? However, if the remote updates of CFS works as expected, the removal of the TICK_NS for CFS is not intentional? -- #include <best/regards.h> Patrick Bellasi
