Will rr work on my system (original) (raw)

This question mostly pertains to Virtual Machines rather than real hardware. To check if it's supposed to work execute the following

on Intel CPUs:

 $ perf stat -e br_inst_retired.conditional true

 Performance counter stats for 'true':

            95,027      br_inst_retired.conditional

       0.003255114 seconds time elapsed

       0.003127000 seconds user
       0.000000000 seconds sys

Check that br_inst_retired.conditional value is not zero in the output.

Note:

On newer systems you might get an error that says that there is an event syntax error and that br_inst_retired.conditional does not exist. If that occurs, try:

 $ perf stat -e br_inst_retired.cond true

on AMD Ryzen CPUs

$ perf stat -e ex_ret_cond true

 Performance counter stats for 'true':

            17.525      ex_ret_cond:u

       0,002422402 seconds time elapsed

       0,002737000 seconds user
       0,000000000 seconds sys

Check that ex_ret_cond:u value is not zero in the output.

in General

You will also likely have to change your kernel.perf_event_paranoid setting to 1, at least when recording.
That is documented on the Building-And-Installing page.

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