Re: [PATCH] tracing: Fix TRACING_SUPPORT dependency

On Sat, 21 Mar 2009, Ingo Molnar wrote:

quoted

quoted

Hm, do all the tracers even compile on ppc32 with your patch?

We had periodic build failures on weird, unmaintained architectures 
that had no irqflags-tracing support and hence didnt know the 
raw_irqs_save/restore primitives ...

I'm not trying to make things more difficult for you (and we can 
apply your patch if it builds fine and does not cause problems 
elsewhere), but there were some real downsides to not having proper 
irq APIs ...

Note, the issue is not with the hooks into local_irq_save/restore, 
but with the entry.S code. That code is very sensitive where the 
irqs are enabled and disabled.

i know. What i'm talking about is that non-lockdep architectures 
have the habit of not defining raw_local_irq_save() - which the 
tracing core relies on.

Since we know that's not an issue with PPC32, perhaps we should add (I 
hate to do this)...


	depends on TRACE_IRQFLAGS_SUPPORT || PPC32

And document that the "|| PPC32" should go when PowerPC32 gets its act
together.  :-/

-- Steve