I am using perf from linux-2.6.36-gentoo-r4. The /proc/sys/kernel/perf_event_paranoid is set to 0, so there should be no problems from there.
Because long-running application I am profiling sometimes crashes for some indetermined reason (no information as to reason for it stopping working could be found by me), I turned to system-wide profiling with perf events.
The application in question does parallelized numerical calculations, using MPI (Message Passing Interface) for communication. Before running the application (with mpirun) I have started recording system-wide profile data on one of nodes it is run with:
$ perf record -o perf.all.cycles,graph.data -g -e cycles -a &
After I have realized that application crashed, I have killed the perf task.
It had left
$ du -sh perf.all.cycles,graph.data
14G perf.all.cycles,graph.data
14GB of data. Unfortunately perf report doesn't support the -a switch.
How can I analyze system-wide profiling data from perf tool?
Added 2011.08.12
Simply running perf report doesn't produce useful output:
$ perf report -i perf.all.cycles,graph.data
#
# (For a higher level overview, try: perf report --sort comm,dso)
#
That is the whole of output from 14GB profile data...