Re: [Gcl-devel] Building GCL from CVS on Ubuntu 12.04

[Raymond Toy]

>>>>> "Camm" == Camm Maguire <address@hidden> writes:

    Camm> I haven't updated cvs head recently as I've been trying to
    Camm> solidify the experimental branch, which I hope to make the

Oh.  Maybe I should try the experimental branch.

    >> Why do you need a heap ceiling?  How would I find out a value
    >> for Solaris/sparc?

    Camm> gcl uses the sbrk system call to grow memory contiguously
    Camm> from the end of the .data section of the executable.
    Camm> Various systems load shared libraries at some arbitrary (but
    Camm> 'basically' fixed) address above this point.  Alas, I have

I'm not 100% sure about this, but there's a comment in the cmucl
sources for sparc that says:

 * It may be possible to increase the size of the dynamic spaces even
 * further, but Casper H.S. Dik says shared libraries are loaded
 * directly under the stack, so we need to leave some space for the C
 * stack and shared libraries.  He also says the top of stack is
 * 0xffbf0000 for Ultrasparcs in Solaris 7+, but it's 0xf0000000 for
 * sun4m (and 4u in S2.6-) 0xe0000000 for sun4d)
 *
 * Shared libraries can be mapped anywhere there's room.

I guess that means they aren't fixed, but you can grow to a fairly
large value if you don't load up tons of shared libraries.

Ray