* K.R. Foley <kr@xxxxxxxxxx> wrote:Well to produce useful results, amlat requires Andrew's rtc-debug patch that modifies the rtc driver as well as traps so that timings are kept when the isr gets run and when the rtc device is read to track scheduling latencies. Also if this patch was applied the value being read by amlat from the rtc device would be the last interrupt time instead of the interrupt info that rtc normally produces. So the latency values being spit out are bogus, but it's good enough to exercise the rtc.
Running amlat [...]
btw., to get good 'realfeel' results i had to apply the attached patch. Especially when running realfeel over the network it can easily happen
that it's delayed for some time and gets out of sync with the RTC. So
after a new maximum latency has triggered the code now waits 10 periods
to wait for the timings to recover.
this does not hurt the latency measurements in any way - latencies that
occur after these 10 ticks (~5 msecs) are over are still fully measured
and reported.
amlat produces weird output for me, continuously increasing latency
values:
latency = 2967939 milliseconds
latency = 2967950 milliseconds
sigint
max jitter = 0 microseconds
maybe some /dev/rtc API detail changed? Or is this the normal output?
Ingo