how to determine a programs memory usage at runtime?

David Roundy droundy at
Tue Jun 22 05:25:38 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).

Might it be worthwhile adding to the foreignPtr interface a way of telling
the RTS how much memory that foreignPtr actually uses? It might be useable
in an advisory sense in deciding which garbage to collect, or just in an
informational sense (as here), when one wants to see how much memory is
used (or, for example, when profiling).

One could also add an extra "user" flag, so perhaps when profiling memory
usage one could look at only "mmapped" memory usage, or something like
that.  The "user" flag could perhaps be ignored when compiling without
David Roundy

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