perf.data file has no samples

Question

I am using perf 3.0.4 on ubuntu 11.10. Its record command works well and displays on terminal 256 samples collected. But when I make use of perf report , it giv

Answer 1

The number of samples reported by the perf record command is an approximation and not the correct number of events (see perf wiki here).

To get the accurate number of events, dump the raw file and use wc -l to count then number of results:

perf report -D -i perf.data | grep RECORD_SAMPLE | wc -l

This command should report 0 in your case where perf report says it can't find events.

Let us know more information about how you use perf record, which event are you sampling, which hardware, which program.

EDIT: you can try first to increase the sampling period or frequency with the -c or -F options