svn commit: r222356 - projects/pseries/kern

[John Baldwin]

On Friday, May 27, 2011 10:27:28 am Nathan Whitehorn wrote:
> Author: nwhitehorn
> Date: Fri May 27 14:27:28 2011
> New Revision: 222356
> URL: http://svn.freebsd.org/changeset/base/222356
> 
> Log:
>   On multi-core, multi-threaded PPC systems, it is important that the threads
>   be brought up in the order they are enumerated in the device tree (in
>   particular, that thread 0 on each core be brought up first). The SLIST
>   through which we loop to start the CPUs has all of its entries added with
>   SLIST_INSERT_HEAD(), which means it is in reverse order of enumeration
>   and so AP startup would always fail in such situation (causing a machine
>   check or RTAS failure).
>   
>   The best fix is probably to change this from a LIST to a TAILQ, but fix
>   this by looping through to add new cpus to the end of the list.

Just make it a STAILQ.  That has a STAILQ_INSERT_TAIL() method and doesn't
change the ABI of 'struct pcpu'.  It just adds an extra pointer to the head.

-- 
John Baldwin