The prep-script.sh
will setup the latest Node and install the latest perf version on your Linux box.
When you want to generate the flame graph, run the following (folder locations taken from install script):
sudo sysctl kernel.kptr_restrict=0
# May also have to do the following:
# (additional reading http://unix.stackexchange.com/questions/14227/do-i-need-root-admin-permissions-to-run-userspace-perf-tool-perf-events-ar )
sudo sysctl kernel.perf_event_paranoid=0
perf record -i -g -e cycles:u -- ~/sources/node/node --perf-basic-prof script.js
perf script | egrep -v "( __libc_start| LazyCompile | v8::internal::| Builtin:| Stub:| LoadIC:|\[unknown\]| LoadPolymorphicIC:)" | sed 's/ LazyCompile:[*~]\?/ /' | ~/sources/FlameGraph/stackcollapse-perf.pl > out.perf-folded
~/sources/FlameGraph/flamegraph.pl out.perf-folded > node-flame.svg
The data munging is to help expose the most important bits. There is still some play that I'm working with, but right now it seems to be working.
Alternatives:
perf script | egrep -v "( __libc_start|node::Start\(| LazyCompile | Builtin:| Stub:| LoadIC:|\[unknown\]| LoadPolymorphicIC:)" | ../FlameGraph/stackcollapse-perf.pl | grep "uv_run" > out.perf-folded
perf script | egrep -v "( __libc_start|node::Start\(| LazyCompile | v8::internal::| Builtin:| Stub:| LoadIC:|\[unknown\]| LoadPolymorphicIC:)" | ../FlameGraph/stackcollapse-perf.pl | grep "uv_run" > out.perf-folded
I'm interested in the function calls. There's a lot of
module._something
,garbage collection
and_ZN2v88internal5Scope11LookupLocalEPKNS0_12AstRawStringE
stuff in the graph together with function calls. Can I remove all the other stuff and only have the function calls?