Re: [Caml-list] A question about GC.

[Guillaume Yziquel <guillaume.yziquel@gmx.ch>]

Le Monday 13 Jun 2011 à 09:35:41 (+0900), Yoonseok Ko a écrit :
> Hello everyone.
> 
> I have two questions.
> 
> 1. Is there any solution? Explicit garbage collection is too slow
> and hard to collect garbage on time.
>     I want to know what happened in GC, and why GC won't work.

First you'll have to know what kind of values accumulate in the heap. If
they are custom blocks, then you'll have a pointer in the block pointing
to a structure that identifies the kind of values (as a general rule).
If it's a problem in the binding, then looking closely at custom blocks
is likely a good idea.

Do not know about muddy, but it may be a good idea to tweak parameters
in alloc_custom in order to force garbage collection often. If the
problem goes away, I'd recommend reading closely about alloc_custom,
look at how it is implemented, and modify muddy.c accordingly.

Anyhow, for such GC problems, I'd recommend using ocamlviz.

> 2. Sometimes GC log has this message: "Growing gray_vals to 32768k bytes."
>     What does that means?

Good read on the topic:

http://caml.inria.fr/pub/docs/oreilly-book/pdf/chap9.pdf

In the marking phase of Mark & Sweep, gray cells are marked cells whose
descendents are not yet marked.

> Best Regards,
> 
> Yoonseok Ko

-- 
     Guillaume Yziquel