Mike Hommey <m...@glandium.org> writes: > On Mon, Oct 22, 2018 at 02:20:32PM -0700, Panos Astithas wrote: >> To record a profile with the ‘perf’ command run the >> following commands and then load the firefox.symbol.data output file from >> https://perf-html.io: >> > sudo perf record -g -F 999 -p <firefox-bin-pid> >> > sudo perf script -F +pid > firefox.symbol.data > > sudo shouldn't be necessary in either case.
Changing the `kernel.perf_event_paranoid` sysctl (documented in the perf_event_open(2) man page; see also sysctl(8) and /etc/sysctl.conf to change it persistently) may be necessary to use perf as non-root. Also, Jeff Muizelaar <jmuizel...@mozilla.com> writes: > I think sudo will let you have symbolicated kernel stacks which can be handy. Lowering kernel.perf_event_paranoid to 1 or less seems to cover this: empirically on Fedora, the addresses in /proc/kallsyms read as "(null)" if it's set to 2 but give actual addresses if it's lower. (This makes sense: if you can capture kernel stacks with perf then you can easily break KASLR, so there's no point in redacting the symbol table.) --Jed _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
