On Thu, May 07, 2020 at 12:41:07AM +0300, Serge Semin wrote: > Currently neither clocksource nor scheduler clock kernel framework > support the clocks with variable frequency. Needless to say how many > problems may cause the sudden base clocks frequency change. In a > simplest case the system time will either slow down or speed up. > Since on CM2.5 and earlier MIPS GIC timer is synchronously clocked > with CPU we must set some limitations on using it for these frameworks > if CPU frequency may change. First of all it's not safe to have the > MIPS GIC used for scheduler timings. So we shouldn't proceed with > the clocks registration in the sched-subsystem. Secondly we must > significantly decrease the MIPS GIC clocksource rating. This will let > the system to use it only as a last resort. > > Note CM3.x-based systems may also experience the problems with MIPS GIC > if the CPU-frequency change is activated for the whole CPU cluster > instead of using the individual CPC core clocks divider. May be there is no alternative but the code looks a bit hacksih. Isn't possible to do something with the sched_mark_unstable? Or just not use the timer at all ?
