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Re: [patch] Allow -mcmodel=large for x86-64 target


On Sat, Dec 29, 2001 at 09:59:10PM +0100, Jan Hubicka wrote:

 > It does not work - at least not fully.
 > Large code model specifies no limitations for the code size so the
 > jumps needs not to be relative that are limited to 32bit. THis is tricky
 > and expensive to implement.

Ah, I see.

 > What exactly do you need? Why medium is not enought?

The kernel VM layout for NetBSD/x86_64 is larger than will fit in either
kernel or medium models.  The issue is the amount of VM required for 2
recursive linear PTE mappings (one for the current process, one for the
"alternate" PTE spaced used to operate the page tables of a non-current
process).

The kernel does not link unless large is used ("relocation truncted" errors).

-- 
        -- Jason R. Thorpe <thorpej@wasabisystems.com>


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