On Mon, Feb 12, 2018 at 09:42:05AM -0800, Raghavendra Rao Ananta wrote: > Hi Jiri, > > Thank you for the response. > > Does perf tool has its own check to see if the CPU was offline during the > lifetime of an event? If so, it might ignore these type of events.
nope, we don't check on that > > Initially, I tested the same using perf tool and found similar results. > Then I debugged further and found that the perf core was actually sending > data to the userspace (copy_to_user()) and the corresponding count for the > data. Hence, I tested this further by writing my own userspace application, > and I was able to read the count through this, > even when the CPU was made offline and back online. > > Do you think we also have to modify the perf tool accordingly? hum, I wonder what's wrong.. will check jirka