On Wed, 28 Feb 2018, Felipe Balbi wrote: > Thomas Gleixner <tglx@xxxxxxxxxxxxx> writes: > > All numbers in micro seconds! What happens if you load the system or > > restrict C-States? > > added intel_idle.max_cstate=0 to cmdline. Still see some failures, > albeit a lot more rare, for example, caught one on iteration 8 of > 8192Hz: > > 8192Hz: 1 2 3 4 5 6 7 > PIE delta error: 0.000135 should be close to 0.000122 > > That is, however, only 13 uS late. Is that within the limits of "we > don't quite care"? I think so. 13us (depending on the machine) can easily happen if multiple interrupts/timers happen at the same time or if something keeps interrupts disabled for a few microseconds which is certainly possible. What kind of system is this? > BTW, it took some effort to get that one failure. I'll leave rtctest > running in a long loop and try to figure out approximately how frequently > it fails, but it seems like it's within the realm of "don't care", would > you agree? Yes. Thanks, tglx
