Archives of the Caml mailing list > Message from Lionel Elie Mamane

Browse thread

OCaml runtime using too much memory in 64-bit Linux

Adam Chlipala
- Gerd Stolpmann
  - Adam Chlipala
    - Samuel Mimram
    - Romain Beauxis
      - Vladimir Shabanov
        
        Xavier Leroy
        
        Brian Hurt
        
        Romain Beauxis
        
        Markus Mottl
        
        Stefan Monnier
        
        Brian Hurt
        
        Lionel Elie Mamane
        
        Stefan Monnier
        
        Lionel Elie Mamane
        
        Lionel Elie Mamane
- Romain Beauxis

Date:	-- (:)
From:	Lionel Elie Mamane <lionel@m...>
Subject:	Re: [Caml-list] Re: OCaml runtime using too much memory in 64-bit Linux

On Wed, Nov 14, 2007 at 05:45:44PM +0100, Lionel Elie Mamane wrote:

> In particular, the addressing space of a 64 bit machine is, well... 64
> bits, by definition. For 4kiB = 2^12 B pages, one thus needs a table
> of size 2^(64-12) = 2^52 bytes, that is 4 EB. That is, on any machine
> with less than that of memory (and overcommit to 2), the program will
> not run. Even at one bit (and not byte) per page, that is still
> 16PB...

> Big pages don't get you out of the problem. 4MB pages only buy you a
> factor 1024, that is 4PB and 16GB.

I got my prefixes all wrong... It is 4PiB, 16TiB, 4TiB and 16GiB...

-- 
Lionel