Have you tried to use 'perf probe' to achieve any useful instrumentation on a real app? I just tried out the 'glibc:free' usecase and it's barely usable. Firstly, the recording very frequently produces overruns: $ perf record -e probe_libc:free -aR sleep 1 [ perf record: Woken up 169 times to write data ] [ perf record: Captured and wrote 89.674 MB perf.data (~3917919 samples) ] Warning:Processed 1349133 events and lost 1 chunks! Using -m 4096 made it work better. Adding -g for call-graph profiling caused 'perf report' to lock up: perf record -m 4096 -e probe_libc:free -agR sleep 1 perf report [ loops forever ] I've sent a testcase to Arnaldo separately. Note that perf report --stdio appears to work. Regular '-e cycles -g' works fine, so this is a uprobes specific bug. Thanks, Ingo -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>