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Re: Process map and fork problems
- From: Achim Gratz <Stromeko at NexGo dot DE>
- To: cygwin at cygwin dot com
- Date: Wed, 20 Apr 2016 11:24:32 +0000 (UTC)
- Subject: Re: Process map and fork problems
- Authentication-results: sourceware.org; auth=none
- References: <loom dot 20160420T121651-786 at post dot gmane dot org> <20160420104633 dot GA26118 at calimero dot vinschen dot de> <loom dot 20160420T124825-644 at post dot gmane dot org> <20160420111431 dot GB13570 at calimero dot vinschen dot de>
Corinna Vinschen <corinna-cygwin <at> cygwin.com> writes:
> > I think all the affected machines have 4GB memory installed, but the
> > option may not have been default when they were installed.
> They never are default. Default is 2 Gigs application VM, 2 Gigs
> kernelÌ memory space. Specifying /3Gb means 3 Gigs application VM
> vs. 1 Gig kernelÌ memory space. That's not always a good thing
> since it could lead to kernel memory pool exhaustion.
I meant "not default in the base install image provided by corporate IT".
I'll have to ask if they have some special procedure to switch it on.
> > With /3GB you mean 4GT (aka PAE), right? And 32bit is without PAE?
> No, PAE works differently, using different calls. I'm talking abut
> the normal 32 bit address space of a 32 bit CPU.
Hmm. Microsoft's 4GT documentation makes you believe that /3GB and PAE is
always coupled, though. But then even non-/3GB might laready use some PAE
facilities anyway. But I guess it's not important.
> It can only know its own heap. But keep in mind that the heap can
> be differently sized in different applications. The heap only *starts*
> as a 384Meg heap, it could easly grow in big apps (gcc, emacs, ...)
> when calling sbrk.
So it can grow only so much until it runs into the first loaded DLL above?
Or does it fragment into yet unused areas then?