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* CONFIG_DEBUG_PAGEALLOC generates WARN_ON() in ppc32 hash
@ 2009-03-27 11:56 Kumar Gala
  2009-03-27 23:05 ` Benjamin Herrenschmidt
  0 siblings, 1 reply; 4+ messages in thread
From: Kumar Gala @ 2009-03-27 11:56 UTC (permalink / raw)
  To: Benjamin Herrenschmidt; +Cc: LinuxPPC Mailing List

Ben,

If we have CONFIG_DEBUG_PAGEALLOC enabled we end up hitting the  
WARN_ON() in set_pte_at() when we boot.  This appears because we've  
already setup pte's via mapin_ram() after which we end up calling  
kernel_map_pages().

So I'm not sure if __change_page_attr() should be doing something  
different or if the WARN_ON() should be conditional on ! 
CONFIG_DEBUG_PAGEALLOC

- k

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: CONFIG_DEBUG_PAGEALLOC generates WARN_ON() in ppc32 hash
  2009-03-27 11:56 CONFIG_DEBUG_PAGEALLOC generates WARN_ON() in ppc32 hash Kumar Gala
@ 2009-03-27 23:05 ` Benjamin Herrenschmidt
  2009-03-28 16:21   ` Kumar Gala
  0 siblings, 1 reply; 4+ messages in thread
From: Benjamin Herrenschmidt @ 2009-03-27 23:05 UTC (permalink / raw)
  To: Kumar Gala; +Cc: LinuxPPC Mailing List

On Fri, 2009-03-27 at 06:56 -0500, Kumar Gala wrote:
> Ben,
> 
> If we have CONFIG_DEBUG_PAGEALLOC enabled we end up hitting the  
> WARN_ON() in set_pte_at() when we boot.  This appears because we've  
> already setup pte's via mapin_ram() after which we end up calling  
> kernel_map_pages().
> 
> So I'm not sure if __change_page_attr() should be doing something  
> different or if the WARN_ON() should be conditional on ! 
> CONFIG_DEBUG_PAGEALLOC

Or use __set_pte_at() ?

Note that C_D_P doesn't work on hash32 anyway...

Ben.

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: CONFIG_DEBUG_PAGEALLOC generates WARN_ON() in ppc32 hash
  2009-03-27 23:05 ` Benjamin Herrenschmidt
@ 2009-03-28 16:21   ` Kumar Gala
  2009-03-28 21:25     ` Benjamin Herrenschmidt
  0 siblings, 1 reply; 4+ messages in thread
From: Kumar Gala @ 2009-03-28 16:21 UTC (permalink / raw)
  To: Benjamin Herrenschmidt; +Cc: LinuxPPC Mailing List


On Mar 27, 2009, at 6:05 PM, Benjamin Herrenschmidt wrote:

> On Fri, 2009-03-27 at 06:56 -0500, Kumar Gala wrote:
>> Ben,
>>
>> If we have CONFIG_DEBUG_PAGEALLOC enabled we end up hitting the
>> WARN_ON() in set_pte_at() when we boot.  This appears because we've
>> already setup pte's via mapin_ram() after which we end up calling
>> kernel_map_pages().
>>
>> So I'm not sure if __change_page_attr() should be doing something
>> different or if the WARN_ON() should be conditional on !
>> CONFIG_DEBUG_PAGEALLOC
>
> Or use __set_pte_at() ?
>
> Note that C_D_P doesn't work on hash32 anyway...

really, what mmu config does it work on ? just hash64?

- k

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: CONFIG_DEBUG_PAGEALLOC generates WARN_ON() in ppc32 hash
  2009-03-28 16:21   ` Kumar Gala
@ 2009-03-28 21:25     ` Benjamin Herrenschmidt
  0 siblings, 0 replies; 4+ messages in thread
From: Benjamin Herrenschmidt @ 2009-03-28 21:25 UTC (permalink / raw)
  To: Kumar Gala; +Cc: LinuxPPC Mailing List


> > Note that C_D_P doesn't work on hash32 anyway...
> 
> really, what mmu config does it work on ? just hash64?

Pretty much :-) It's implemented for hash32 but there are issues
with the BAT mapping that were never quite resolved.

Cheers,
Ben.

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2009-03-28 21:25 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2009-03-27 11:56 CONFIG_DEBUG_PAGEALLOC generates WARN_ON() in ppc32 hash Kumar Gala
2009-03-27 23:05 ` Benjamin Herrenschmidt
2009-03-28 16:21   ` Kumar Gala
2009-03-28 21:25     ` Benjamin Herrenschmidt

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