Hi all, I just tried in a 2-threaded application to call twice (one call for each thread) perf_event_open syscall with parameters configured to do sampling on MEM INST RETIRED.LATENCY ABOVE THRESHOLD event. Both call succeed.
"mmaping" the file descriptor return by the first call succeed but "mmaping" the second file descriptor results in a "Operation not permitted" error (errno = 1). A work around could be to sample all threads (with pid = -1) including pid and tid in samples and filter samples at processing time. Before switching to this solution I wanted to ask if this a known limitation of the syscall, an error from my side, or a bug (the man page doesn't answer to this question) ? Thanks, Manu -- To unsubscribe from this list: send the line "unsubscribe linux-perf-users" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
