Re: 2.5 kernels fail to start second CPU

[Bill Davidsen]

On Thu, 15 May 2003, William Lee Irwin III wrote:

> On Thu, May 15, 2003 at 02:48:34AM -0700, William Lee Irwin III wrote:
> > Sparse physical APIC ID's are not handled properly. This should correct
> > them.
> 
> I forgot to count the BSP in the initial count of the number of kicked
> cpus. This patch does it correctly.
> 
> To handle sparse physical APIC ID's properly the phys_cpu_present_map
> must be scanned beyond bit NR_CPUS while ensuring no more than NR_CPUS
> are woken in order not to attempt to wake non-addressible cpus.
> 
> The following patch adds that logic to smp_boot_cpus() and corrects the
> failure to wake secondaries reported by dhowells, with successful
> wakeup, runtime, reboot, and halting reported after it was applied.

While you are (somewhat) on the topic of starting processors, I want to
benchmark and application on a dual Xeon system. I want to try these
configurations, preferably without opening the box, since it's in
another time zone.

  2 cpu w/ ht		normal boot
  2 cpu w/o ht		noht
  1 cpu w/o ht		nosmp noht
  1 cpu w/ ht		???

It looks as if maxcpus=2 counts physical units? I can't try it until Monday.

-- 
bill davidsen <[e-mail]>
  CTO, TMR Associates, Inc
Doing interesting things with little computers since 1979.