On Fri, 20 Apr 2012 19:12:12 +0400 SerP <serp...@gmail.com> wrote: > Hi! > We have developped a daemon on ocaml using the lwt lib(libev). It processes > about 800 requests per second, but it increases to 2 Gb in memory for a > hour of work. We have studied the problem for a long time, using mtrace, > mallinfo and other tools, and we tried to change GC params. We found out > that setting up GC.minor_heap_size=10Mb а major_heap_increment=2Мb will > make the daemon grow slower. mallinfо shows that the memory (1,5G) is > allocated using mmap (blkhd field in mallinfo struct) and arena size - > about 20M In this case, first calls of GC.compact compress the daemon to > 200 Mb (live -110Mb) , and mallinfo show decreasing of total size of memory > allocated by mmap. The daemon keeps growing, but it allocates the memory to > arena (using brk), and calls of GC.compact leads to decrease of heap_bytes > to 200M, but arena size (1.5 Gb) does not decrease, just doing less > uordblks and more fordblks (fileds I.e., after first calls of GC.compact, > the daemon starts using brk much more than mmap, and cant memory given back > to the system.
Alternative malloc implementation may well be worth a try. I've seen the cases when glibc was constantly growing RSS while tcmalloc was on stable level (and 10x less), guessing due to fragmentation. Maybe related, see PR#5389 for ocaml compaction related issues. Also have a look at http://ygrek.org.ua/p/code/mlvalues.py for the way to peep into ocaml heap at runtime. -- ygrek http://ygrek.org.ua -- Caml-list mailing list. Subscription management and archives: https://sympa-roc.inria.fr/wws/info/caml-list Beginner's list: http://groups.yahoo.com/group/ocaml_beginners Bug reports: http://caml.inria.fr/bin/caml-bugs
