Profiling CPU usage of a ceph command (gperftools)

Dec 10, 2013 loic

After compiling Ceph from sources with:

./configure --with-debug CFLAGS='-g' CXXFLAGS='-g'

The crushtool test mode is used to profile the crush implementation with:

LD_PRELOAD=/usr/lib/libprofiler.so.0 \ CPUPROFILE=crush.prof src/crushtool \ -i src/test/cli/crushtool/one-hundered-devices.crushmap \ --test --show-bad-mappings

as instructed in the cpu profiler documentation. The resulting crush.prof file can then be analyzed with

google-pprof --ignore=vector --focus=bucket_choose \ --gv ./src/crushtool crush.prof

and displays the following result:

Any Ceph command can be profiled in this way.