[Mono-dev] Memory usage differences between GC and OS

[Andreas Nahr]

> Well, the point of the email is the following: something I've found
> several times is a situation where GC.GetTotalMemory gives me something
> like, let's say, 40Mb, then VIRT is something like 200Mb and RES is
> 80Mb.
>
> Mark refreshed me that jitted and non-jitted code will be eating up
> memory, then metadata and so on... and of course the GC internals with
> things like free memory lists and so on. But, I think it would be great
> for application developers to really understand how this is working and
> where your memory is going, because the diff between 40Mb and 200Mb is
> simply... huge!

As you wrote: That 200Mb isn't memory! It is address space.
And as you have about 17592186044416 Mb of address space available on a
64-bit system 200MB isn't much to worry about.

Moreover I don't really see much sense in trying to "tweak" that. But in
case you are interested: Afaik one of the big blocks is simply the raw
assemblies. Each of them gets loaded memmapped, so their entire file size
counts into your VIRT.

Happy Hacking
Andreas