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Date: Sat, 21 Mar 2009 12:41:42 -0400 (EDT)
From: Steven Rostedt <rostedt@goodmis.org>
To: Ingo Molnar <mingo@elte.hu>
Subject: Re: [PATCH] tracing: Fix TRACING_SUPPORT dependency
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On Sat, 21 Mar 2009, Ingo Molnar wrote:
> > > 
> > > 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