Version française
Home     About     Download     Resources     Contact us    
Browse thread
[Caml-list] Slow GC problem
[ Home ] [ Index: by date | by threads ]
[ Search: ]

[ Message by date: previous | next ] [ Message in thread: previous | next ] [ Thread: previous | next ]
Date: -- (:)
From: David Monniaux <monniaux@d...>
Subject: Re: [Caml-list] Slow GC problem
On Mon, 7 Apr 2003, Chris Hecker wrote:

> >I am concluding that gc is to blame.
> Did you profile to check this assumption?  What's the profile look like?

A little bit of experience here: I have done such profiles with the
following tools:

* gprof (compile with ocamlopt -p and gcc -pg);

* oprofile (hardware-based, supports only certain platforms including
  Linux/x86; can profile not only clock ticks, but also events such as
  cache faults).

My (somehow unsurprising) experience was that:
* GC generates 15-20% of cache faults
* GC takes about 15% of time.
A conjecture on my part is that using a lot of unboxed floats is partly
responsible.

My conclusion: you should definitely profile your code before starting
to incriminate the GC or any other module.


David Monniaux            http://www.di.ens.fr/~monniaux
Laboratoire d'informatique de l'École Normale Supérieure,
Paris, France

-------------------
To unsubscribe, mail caml-list-request@inria.fr Archives: http://caml.inria.fr
Bug reports: http://caml.inria.fr/bin/caml-bugs FAQ: http://caml.inria.fr/FAQ/
Beginner's list: http://groups.yahoo.com/group/ocaml_beginners