Re: perf: rdpmc bug when viewing all procs on remote cpu

Vince Weaver
2019-01-10T17:50:58Z

On Thu, 10 Jan 2019, Vince Weaver wrote:

> However if you create an all-process attached to CPU event:
> perf_event_open(attr, -1, X, -1, 0);
> the mmap event index is set as if this were a valid event and so the rdpmc
> succeeds even though it shouldn't (we're trying to read an event value
> on a remote cpu with a local rdpmc).

For a test case, try the
tests/rdpmc/rdpmc_attach_other_cpu
test found in my perf_event_tests suite
git clone https://github.com/deater/perf_event_tests

I can trigger it with current git on an intel machine, but not on an AMD
machine. Possibly because it is defaulting to one of the fixed counter
slots?

Vince