From owner-freebsd-alpha  Fri Jun  8  3:39:41 2001
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Date: Fri, 8 Jun 2001 11:38:21 +0100 (BST)
From: Doug Rabson <dfr@nlsystems.com>
To: Andrew Gallatin <gallatin@cs.duke.edu>
Cc: Wilko Bulte <wkb@freebie.demon.nl>, <freebsd-alpha@freebsd.org>
Subject: Re: 8 CPU SMP attempt
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On Thu, 7 Jun 2001, Andrew Gallatin wrote:

>
> Wilko Bulte writes:
>  >
>  > Possible. I cannot really try as the smallest config would be a single
>  > CPU board housing 2 CPUs. Or do we honor the maxcpus (or whatever it
>  > is called..) SRM variable?
>
> "whatever its called" works, at least on Matt's 4100, so you could see if a
> dual or single processor config boots.  I think its just a bitmask of
> available CPUs on most (all?) platforms.

I use this patch to ignore all except the first secondary CPU.

Index: mp_machdep.c
===================================================================
RCS file: /home/ncvs/src/sys/alpha/alpha/mp_machdep.c,v
retrieving revision 1.20
diff -u -r1.20 mp_machdep.c
--- mp_machdep.c	2001/05/15 23:22:17	1.20
+++ mp_machdep.c	2001/05/22 13:17:13
@@ -363,13 +363,14 @@
 		}
 		all_cpus |= 1 << i;
 		mp_ncpus++;
+		break;
 	}
 	PCPU_SET(other_cpus, all_cpus & ~(1 << boot_cpu_id));

 	for (i = 0; i < hwrpb->rpb_pcs_cnt; i++) {
 		if (i == boot_cpu_id)
 			continue;
-		if (all_cpus & 1 << i)
+		if (all_cpus & 1 << i)
 			smp_start_secondary(i);
 	}
 }

-- 
Doug Rabson				Mail:  dfr@nlsystems.com
					Phone: +44 20 8348 6160



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