README-py

*** OVERVIEW ***

This tool is composed by three scripts:

./stackcollapse-perf.py	
	generates formatted performance data starting from the output
	of "perf script".

./stackcollapse-stap.py
	generates formatted performance data starting from the output
	of the below example.

./flamegraph.py
	generates an SVG flamegraph starting from the output of one
	of the previous script.

The following example involves the execution of a one-second sleep.

*** PERF USAGE ***

perf record -a -g -F 1000 sleep 1
perf script | ./stackcollapse-perf.py | ./flamegraph.py > perf-kernel.svg

*** SYSTEMTAP USAGE ***

stap -s 32 -D MAXBACKTRACE=100 -D MAXSTRINGLEN=4096 -D MAXMAPENTRIES=10240 \
    -D MAXACTION=10000 -D STP_OVERLOAD_THRESHOLD=5000000000 --all-modules \
    -ve 'global s; probe timer.profile { s[backtrace()] <<< 1; }
    probe end { foreach (i in s+) { print_stack(i);
    printf("\t%d\n", @count(s[i])); } } probe timer.s(1) { exit(); }' \
    > out.stap-stacks
./stackcollapse-stap.py out.stap-stacks > out.stap-folded
cat out.stap-folded | ./flamegraph.py > stap-kernel.svg