[PATCH] kernel/irq/handle.c fix kstat_irqs_cpu and irq_to_desc symbols

[Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>]

On Mon, Mar 16, 2009 at 05:53:37PM -0400, Mathieu Desnoyers wrote:
>* Josh Boyer (jwboyer@linux.vnet.ibm.com) wrote:
>> On Mon, Mar 16, 2009 at 04:25:00PM -0400, Mathieu Desnoyers wrote:
>> >* Josh Boyer (jwboyer@linux.vnet.ibm.com) wrote:
>> >> On Mon, Mar 16, 2009 at 03:44:59PM -0400, Mathieu Desnoyers wrote:
>> >> >* Josh Boyer (jwboyer@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....
>> >> 
>> >
>> >Can I get your full .config ?
>> 
>> Sure, attached.  Note, this is just:
>> 
>> make ppc64_defconfig
>> make vmlinux
>> 
>> josh
>
>Can you try moving this code around ?

Yep, allows vmlinux and modules to build just fine.  Here's a patch for you ;)

Mathieu :

This build problem was exhibited because of the added
EXPORT_SYMBOL(irq_to_desc) in the LTTng tree, but only on powerpc.

Applies on 2.6.29-rc8.

From: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
---
 include/linux/irqnr.h |    4 ++++
 kernel/irq/handle.c   |    2 +-
 2 files changed, 5 insertions(+), 1 deletion(-)

Index: linux-2.6-lttng/include/linux/irqnr.h
===================================================================
--- linux-2.6-lttng.orig/include/linux/irqnr.h	2009-02-10 22:53:36.000000000 -0500
+++ linux-2.6-lttng/include/linux/irqnr.h	2009-03-16 18:40:01.000000000 -0400
@@ -38,6 +38,10 @@ extern struct irq_desc *irq_to_desc(unsi
 
 #endif /* CONFIG_GENERIC_HARDIRQS */
 
+extern int nr_irqs;
+struct irq_desc;
+extern struct irq_desc *irq_to_desc(unsigned int irq);
+
 #define for_each_irq_nr(irq)                   \
        for (irq = 0; irq < nr_irqs; irq++)
 
Index: linux-2.6-lttng/kernel/irq/handle.c
===================================================================
--- linux-2.6-lttng.orig/kernel/irq/handle.c	2009-03-16 18:38:51.000000000 -0400
+++ linux-2.6-lttng/kernel/irq/handle.c	2009-03-16 18:40:01.000000000 -0400
@@ -473,6 +473,6 @@ unsigned int kstat_irqs_cpu(unsigned int
 	struct irq_desc *desc = irq_to_desc(irq);
 	return desc ? desc->kstat_irqs[cpu] : 0;
 }
-#endif
 EXPORT_SYMBOL(kstat_irqs_cpu);
+#endif
 

-- 
Mathieu Desnoyers
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