| Date | Wed, 24 Jul 2019 10:53:25 +0200 | From | Jiri Olsa <> | Subject | Re: [RFC 00/79] perf tools: Initial libperf separation |
| |
On Mon, Jul 22, 2019 at 09:23:36AM -0700, Ian Rogers wrote: > This is really helpful and thank you for taking the initiative! I've > no real feedback other than to offer support. > We've been looking in this direction to avoid memory overhead in: > https://github.com/google/perf_data_converter > Some use cases: > 1) streaming protobuf rather than perf.data files,
hum, we already have the CTF conversion support (perf data convert --to-ctf), perhaps we could add support for profile.proto, so you dont need special app
> 2) using libperf inside of a runtime with JIT for a symbolization > story that can reduce the storage/memory overhead of the current 'perf > record' and 'perf inject -j'. Something similar is done here: > https://github.com/jvm-profiling-tools/async-profiler/blob/936a9fea8dafc5d0674860d229a1b3d86d295e2f/src/perfEvents_linux.cpp
I think that once we have the mmap interface in place we can discuss some higher level interface that would help you
> 3) self profiling with dwarf based call graphs, to avoid stack samples > being visible outside of the process which could be a security > concern.
same as above, once we have mmap support I think this is one of the things we definitely want to add to libperf
> > Most of our tooling is C++ rather than C, and we run into issues like > tools/include/linux/list.h using 'new' as a variable name. The
libperf has currently the full object separation, so outside users dont see its object struct's inners.. that should solve the 'new' issue
> duplication of header files in tools/, the importance of -I precedence > and the use of -include have been other build system gotchas - > principally because there are so many files with exactly the same > name. I don't know if in the reorganization into a library this can be > simplified.
libperf will be public so the building should be hopefuly simpler and straightforward
thanks a lot for the feedback, jirka
|