how to determine a programs memory usage at runtime?

Bernard James POPE bjpop at
Tue Jun 22 05:16:27 EDT 2004

On Tue, Jun 22, 2004 at 09:27:40AM +0100, Simon Marlow wrote:
> On 22 June 2004 03:51, Bernard James POPE wrote:
> > The mblocks_allocated variable should give me what I want.
> > 
> > I think having access to this would also be useful to people who are
> > profiling their programs. You see a few papers where people want to
> > report how much memory their application needs, and having a
> > high-water mark is usually good enough. Beats trying to get the
> > information from top. 
> Note that this only counts memory allocated by the GHC storage manager;
> it doesn't include the data segments, malloc(), the C stack, or other
> mmap()'d stuff.  Be careful if your program is using any of these other
> allocation methods (perhaps via an external library through the FFI).

Ah, that's a good point. I didn't think of that.

For what it is worth I've put a simple Haskell wrapper to mblocks_allocated
on the web. It provides this function:

   megaBytesAllocated :: IO Integer

On my simple tests it seems reliable, when compared to what top says.

I've put it here in case anyone wants to use it:


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