[PATCH] fix for process virtual size display

Chris January chris@atomice.net
Sat May 24 19:06:00 GMT 2003

> On Tue, May 20, 2003 at 08:31:06AM -0400, Joe Buehler wrote:
> >Pierre A. Humblet wrote:
> >
> >>MEM_RESERVE Reserves a range of the process's virtual address space
> >>without allocating any actual physical storage in memory or in
> the paging
> >>file on disk. Other memory allocation functions, such as malloc and
> >>LocalAlloc, cannot use a reserved range of memory until it is released.
> >
> >Yes -- I am wondering what Windows is really doing internally, though.
> >
> >What does it mean that no physical storage is allocated in memory?
> >Obviously
> >no pages are allocated.  But do they allocate page tables so
> they can catch
> >accesses to the reserved memory?  Or for performance reasons, so it can
> >be changed to committed faster?
> >
> >They're keeping track of reserved memory somehow, the question is what
> >amount of resource is being dedicated to the task.
> If I understand this thread correctly, Chris is not comfortable with the
> patch as is.  So, I'll wait for an updated patch given his suggestions?

I did some more reading around this and found that a lot of Unix systems
don't actually have a concept of reserved memory. Given that a large amount
of memory is reserved, but never comitted by Cygwin processes, this reserved
memory skews the vmsize quite a bit. With this patch, the values are a lot
more like Linux, therefore I'm actually for this patch being committed.


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