Subject: Re: Wine & NetBSD?
To: Chuck Cranor <chuck@xxx.research.att.com>
From: Bang Jun-Young <bjy@mogua.org>
List: tech-kern
Date: 11/27/2001 14:30:52
On Wed, Nov 21, 2001 at 10:03:30PM -0500, Chuck Cranor wrote:
>    the problem with your patch is this: suppose you set addr to a value
> that is in the 128MB prior to vm_taddr.   furthermore, suppose that memory
> is already fully allocated.   what will happen?   since the area before
> the text is full, the mmap code will skip to the next hole.   where is
> the next hole?   --- it is the start of the heap/malloc area.   the next
> time sbrk is called to grow the heap it will blow away the mapping you
> just established (sys_obreak uses MAP_FIXED).   i think that's bad.

I admit I was wrong. The patch was incomplete. sys_obreak should
be also modified to avoid the problem you pointed out.
Probably uvm_map_findspace will help, but modifying sys_obreak
won't be accepted either ("If it ain't broke, don't fix it").

Conclusion: the only solution to Wine problem would be to maintain
NetBSD specific patches in pkgsrc tree. 

Jun-Young

-- 
Bang Jun-Young <bjy@mogua.org>