Re: 2.6.15-mm4 failure on power5

[Ingo Molnar <mingo@elte.hu>]

* Andrew Morton <akpm@osdl.org> wrote:

> > [ if this indeed is the case then i'll add irqs_off() checks to
> >   DEBUG_MUTEXES=y, to ensure that the mutex APIs are never called with 
> >   interrupts disabled. ]
> 
> Yes, I suppose so.  But we're already calling might_sleep(), and 
> might_sleep() checks for that.  Perhaps the might_sleep() check is 
> being defeated by the nasty system_running check.

ah ... indeed.

> There's a sad story behind that system_running check in might_sleep().  
> Because the kernel early boot is running in an in_atomic() state, a 
> great number of bogus might_sleep() warnings come out because of 
> various code doing potentially-sleepy things.  I ended up adding the 
> system_running test, with the changelog "OK, I give up.  Kill all the 
> might_sleep warnings from the early boot process." Undoing that and 
> fixing up the fallout would be a lot of nasty work.

OTOH, x86 was just fine last i checked, and it has alot more complex 
bootup code than any of the other architectures (due to the sheer number 
of x86 variants).

	Ingo