+-----------------+-----------------+--------+----------+
| PROFILING INFO | WOSIZE | COLOR | TAG |
+-----------------+-----------------+--------+----------+
bits 63 43 42 10 9 8 7 0
+-----------------+-----------------+--------+----------+
+ 21bits + 33bits + 2bits + 10bits +
=== OCaml 4.00.1 with memory profiling support version 0.1
ChangeLog:
* version 0.2: /!\ bytecode and native /!\
- Dump heap image, dump profiling information (especially location information)
and then draw simple graphs using hp2ps
* version 0.1: /!\ bytecode only /!\
- Dump heap image, dump profiling information (especially location information)
and then draw simple graphs using hp2ps
=== OCamlmemprof
Dump a memory image of the application on the disk which contains modified memory
representation (no overhead here, just reduced the wosize field, see picture above),
dump also a file "exe.prof" which contains locations informations of blocks.
Then, you can use the profiler in the memprof/ directory to re-type the heap and obtain
a simple graph.
=== How to use the compiler and the profiler
1- Fork the compiler available on github
> git clone https://github.com/cago/ocaml/
> git checkout 4.00.1+memprof
With OPAM:
> opam remote add memprof https://github.com/cago/opam-repository --kind=git
> opam switch 4.00.1+memprof
2- Compile OCaml and install: bytecode and native !
> ./configure -prefix /path/
> make world world.opt
3- Then, ocamlc and ocamlrun is now available. Compile your application and to dump the heap, you have 3 choices:
* Using OCAMLRUNPARAM=m to dump the heap image after each major garbage collection
e.g.: OCAMLRUNPARAM=m ocamlopt -o exe my_project.ml
* Using a signal: when receiving a HUP signal, the application will dump its
memory on disk for future profiling.
* Using the dumping function in the GC module:
Gc.dump_heap ()
e.g.:
let x = ...
...
Gc.dump_heap ();
...
After that, you have a file which looks like :
heap.dump.<pid-number>.<image-number>
4- Finally, use the profiler:
* on several heap images
> profiler -prof my_exe.prof -heaps 1432
* on one heap image
> profiler -prof my_exe.prof -heap heap.dump.1432.5
If you want more details about location and type, you can add the -loc option:
* on several heap images
> profiler -loc -sizes 1432
* on one heap image
> profiler -loc -size heap.dump.1432.5
=== Contact http://www.ocamlpro.com
If you have any question or bug report, you can use the github bug tracker:
https://github.com/cago/ocaml/
Or contact me:
cagdas.bozman@ocamlpro.com