Re: SPARC32 SMP IRQ15 question

[Daniel Hellstrom <daniel@gaisler.com>]

David Miller wrote:

>From: Daniel Hellstrom <daniel@gaisler.com>
>Date: Wed, 22 Dec 2010 14:23:27 +0100
>
>  
>
>>I will try to create a patch for the atomic layer for SMP LEON systems
>>since they have the CASA instruction.
>>    
>>
>
>But see my other posting, you still have to fix the irq15 problem.
>
>Merely switching to CASA doesn't mean you don't still have a problem
>because spin_lock_irqsave() and other similar pieces of code expect
>they will not be interrupted by smp_call_function() calls.
>  
>
I totally agree, I brought up the atomic layer as an example because it 
could be triggered easiest. The atomic layer can be modified for LEON to 
gain some performance improvements I guess, I made a dirty patch for 
testing it seemed to work but then it freezes in the memory zone lock 
instead.

I will continue my investigations later, first I want to clean up my 
single-CPU patches and submit them to the list.

Daniel