[PATCH] 2.5.8 fix for percpu area

[PATCH] 2.5.8 fix for percpu area

[Dipankar Sarma]

The percpu area stuff is broken in two places -

Missing stub for setup_per_cpu_areas() in the UP case
and missing definition of __per_cpu_data attribute in percpu.h.
Here is a patch that fixes these. Please apply.

Thanks
-- 
Dipankar Sarma  <dipankar@in.ibm.com> http://lse.sourceforge.net
Linux Technology Center, IBM Software Lab, Bangalore, India.


[percpufix-2.5.8-1.patch]


diff -urN linux-2.5.8-base/include/asm-generic/percpu.h linux-2.5.8-percpufix/include/asm-generic/percpu.h
--- linux-2.5.8-base/include/asm-generic/percpu.h	Mon Apr 15 00:48:47 2002
+++ linux-2.5.8-percpufix/include/asm-generic/percpu.h	Tue Apr 16 11:49:28 2002
@@ -4,6 +4,8 @@
 #define __GENERIC_PER_CPU
 #include <linux/compiler.h>
 
+#define __per_cpu_data  __attribute__((section(".data.percpu")))
+
 extern unsigned long __per_cpu_offset[NR_CPUS];
 
 /* var is in discarded region: offset to particular copy we want */
diff -urN linux-2.5.8-base/init/main.c linux-2.5.8-percpufix/init/main.c
--- linux-2.5.8-base/init/main.c	Mon Apr 15 00:48:46 2002
+++ linux-2.5.8-percpufix/init/main.c	Tue Apr 16 11:50:57 2002
@@ -272,6 +272,10 @@
 #define smp_init()	do { } while (0)
 #endif
 
+static inline void setup_per_cpu_areas(void)
+{
+}
+
 #else
 
 #ifdef __GENERIC_PER_CPU

Re: [PATCH] 2.5.8 fix for percpu area

[Rusty Russell]

In message <20020416125716.A31123@in.ibm.com> you write:
> The percpu area stuff is broken in two places -
> 
> Missing stub for setup_per_cpu_areas() in the UP case
> and missing definition of __per_cpu_data attribute in percpu.h.
> Here is a patch that fixes these. Please apply.

You should be including "linux/percpu.h" which defines __per_cpu_data
for UP.

The other fix is to move the whole #ifdef __GENERIC_PER_CPU
... setup_per_cpu_areas(void) { ...#endif out from inside the #ifdef
CONFIG_SMP block (patch sent).

Thanks,
Rusty.
--
  Anyone who quotes me in their sig is an idiot. -- Rusty Russell.

Re: [PATCH] 2.5.8 fix for percpu area

[Dipankar Sarma]

On Wed, Apr 17, 2002 at 04:57:44PM +1000, Rusty Russell wrote:
> In message <20020416125716.A31123@in.ibm.com> you write:
> > The percpu area stuff is broken in two places -
> > 
> > Missing stub for setup_per_cpu_areas() in the UP case
> > and missing definition of __per_cpu_data attribute in percpu.h.
> > Here is a patch that fixes these. Please apply.
> 
> You should be including "linux/percpu.h" which defines __per_cpu_data
> for UP.

I didn't know that existed. This works.

> 
> The other fix is to move the whole #ifdef __GENERIC_PER_CPU
> ... setup_per_cpu_areas(void) { ...#endif out from inside the #ifdef
> CONFIG_SMP block (patch sent).

Ok. I will make a new patch for my own use until you fix gets included.

Thanks
-- 
Dipankar Sarma  <dipankar@in.ibm.com> http://lse.sourceforge.net
Linux Technology Center, IBM Software Lab, Bangalore, India.