Subject: Re: SMP work on sparc64
To: Chris Ross <cross+netbsd@distal.com>
From: Chuck Silvers <chuq@chuq.com>
List: current-users
Date: 04/30/2005 09:16:33
hi,

On Wed, Apr 27, 2005 at 11:56:06AM -0400, Chris Ross wrote:
>   Hi there.  I didn't really get any response on this, so I
> thought I'd ask again.  Is there any work actively ongoing for
> sparc64 SMP support for either -current, or NetBSD 3?
> 
>   I have a quad proc machine that I'd love to have running
> MP without having to load Solaris 10 on it.
> 
>   If anyone has an update on the current status, please let
> me know.

I looked into this again a month or so ago to see where we were at.
right now the first trouble shows up with the secondary CPUs attempt
to switch from the virtual memory mappings that the PROM sets up to
the kernel's.  somewhere in that process the machine locks up.

I looked to see how freebsd does this stuff, and their scheme is much nicer.
instead of the kernel jumping through hoops to remap itself with large TLB
entries, the bootloader takes care of all this by mapping the memory into
which the kernel image is loaded with large TLB entries in the first place.
I think that the freebsd scheme is likely to work better for MP startup
(as well as eliminating a bunch of tricky assembly code).  I'm hoping this
also makes my E4500 go, which currently has this same problem even with
the boot CPU.

I'll make this change eventually unless someone beats me to it.

-Chuck


>                       - Chris
> 
> ps,
>   On a related but separate note, there used to be a web site
> where people would commit money into escrow for coding tasks.
> Does this still exist?  Does anyone remember what/where it is/
> was?