On 30/04/20 2:03 am, Andi Kleen wrote: >> +One caveat with the G and L options is that they work poorly with "Large >> PEBS". >> +Large PEBS means PEBS records will be accumulated by hardware and the >> written >> +into the event buffer in one go. That reduces interrupts, but can give very >> +late timestamps. Because the Intel PT trace is synchronized by timestamps, > > Are you refering to Broadwell here?
I was testing on Coffee Lake > > On Skylake/Goldmont the PEBS event contains the TSC and the time stamp > reported by > perf should report the time the event was sampled based on that TSC. > Or is that not working for some reason? I guess it is not working like that, but perf tools would probably need special rules to sort the events because the they would break the rules of PERF_RECORD_FINISHED_ROUND, wouldn't they?
