cvs commit: src/sys/ia64/ia64 sapic.c

[John Baldwin]

On Monday 14 April 2008 04:34:45 pm Marcel Moolenaar wrote:
> marcel      2008-04-14 20:34:45 UTC
>
>   FreeBSD src repository
>
>   Modified files:
>     sys/ia64/ia64        sapic.c
>   Log:
>   Revision 1.9 changes the delivery mode from the magic constant 0
>   (i.e. fixed delivery) to SAPIC_DELMODE_LOWPRI. While the commit
>   log doesn't mention the change in behaviour, it is believed to be
>   deliberate. In the last 5.5 years this hasn't been a problem. Nor
>   do I think did it make any difference, but who knows. However, I
>   do know that it break SMP support for Montecito-based machines.
>   Switch back to fixed-CPU delivery so that SMP works again. This
>   gives me some time to look more closely at the problem, as well
>   as make sure the I-cache validation as it's implemented currently
>   is sufficient in SMP configurations...

Intel is deprecating the LOWPRI delivery mode on x86 CPUs with x2APIC, so I 
think it is probably best to switch to using FIXED mode on ia64 as well (x86 
has used fixed mode since the new APIC code came in due to LOWPRI being 
effectively useless on P4 CPUs).

-- 
John Baldwin