From mboxrd@z Thu Jan  1 00:00:00 1970
From: compudj@krystal.dyndns.org (Mathieu Desnoyers)
Date: Mon, 16 Mar 2009 16:47:18 -0400
Subject: [ltt-dev] 2.6.29-rc7-lttng-0.110 broken with CONFIG_SLUB
In-Reply-To: <20090316200115.GA22538@yoda.jdub.homelinux.org>
References: <20090316182227.GA2444@yoda.jdub.homelinux.org>
	<20090316194459.GD11878@Krystal>
	<20090316200115.GA22538@yoda.jdub.homelinux.org>
Message-ID: <20090316204718.GB14337@Krystal>

* Josh Boyer (jwboyer at linux.vnet.ibm.com) wrote:
> On Mon, Mar 16, 2009 at 03:44:59PM -0400, Mathieu Desnoyers wrote:
> >* Josh Boyer (jwboyer at linux.vnet.ibm.com) wrote:
> >> Hi All,
> >> 
> >> I was attempting to build a simple ppc64_defconfig using
> >> the latest LTTng tag from git.  When doing a:
> >> 
> >> 	make ppc64_defconfig
> >> 	make
> >> 
> >> I get the error below.
> >> 
> >
> >Hi Josh,
> >
> >Yes, LTTng has been tested with slub, but not for the powerpc64
> >cross-build. Thanks for the report, this is actually a header circular
> >dependency I caused. It should be fixed in LTTng 0.111.
> 
> Bah. Yes, I should have clarified on ppc/ppc64.  Sorry for the confusion
> there.
> 
> >I'll have to update my powerpc64 cross compiler to test it, because I am
> >stucked with a broken gcc 4.1. Please tell me if 0.111 fixes the problem
> >for you or if you encounter other problems.
> 
> Yep, the extern on tb_ticks_per_sec is what I had come up with locally.
> It should work fine, and does indeed get past the error I was seeing.  The
> build now dies with:
> 
> kernel/irq/handle.c:259: error: __ksymtab_irq_to_desc causes a section type conflict
> kernel/irq/handle.c:259: error: __ksymtab_irq_to_desc causes a section type conflict
> make[2]: *** [kernel/irq/handle.o] Error 1
> make[1]: *** [kernel/irq] Error 2
> make: *** [kernel] Error 2
> make: *** Waiting for unfinished jobs....
> 
> josh
> 

Threads like this 
http://lkml.org/lkml/2008/1/13/175

Tells me this kind of problems appears with the symbol is declared
static *and* exported, which does not seem to be the case for
irq_to_desc. It's first declared here :

(supposing CONFIG_GENERIC_HARDIRQS)

include/linux/irqnr.h:

extern struct irq_desc *irq_to_desc(unsigned int irq);

then declared here :

!CONFIG_SPARSE_IRQ :

struct irq_desc *irq_to_desc(unsigned int irq)
{
        return (irq < NR_IRQS) ? irq_desc + irq : NULL;
}
EXPORT_SYMBOL(irq_to_desc);


I don't see the problem.. any idea ? I'll have to install a
cross-compiler to find out what is happening here. What is your compiler
version ?

Mathieu

-- 
Mathieu Desnoyers
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