Re: [fedora-arm] [PATCH] oprofile, perf: Use per-cpu framework

[William Cohen]

On 03/02/2012 06:31 AM, Robert Richter wrote:
>  On 23.02.12 17:25:11, Robert Richter wrote:
> > On 23.02.12 10:12:35, Will Deacon wrote:
> >> On Thu, Feb 23, 2012 at 04:08:23AM +0000, William Cohen wrote:
> >>> I was looking to see why the arm kernel builds for fedora 17 were failing
> with:
> >>>
> >>> arch/arm/oprofile/../../../drivers/oprofile/oprofile_perf.c:28:28: error:
> variably modified 'perf_events' at file scope
> >>>
> >>> The error points to the following line in oprofile_perf.c:
> >>>  
> >>> static struct perf_event **perf_events[nr_cpumask_bits];
> >
> >> That or use NR_CPUS instead (which will be the same as nr_cpu_ids on ARM).
> >
> > William,
> >
> > the patch below uses per-cpu macros and should probably fix the
> > above. But it's *compile tested only*.
>  
>  William,
>  
>  could you give this patch a try? I would like to remove the cpu array
>  implementation and change the code to use the cpu framework.
>  
>  Please, send me also your config for further testing.
>  
>  Many thanks,
>  
>  -Robert 
Hi Robert,

After getting the perf support working on the trimslice machine with the 3.3.0-rc5+ kernel
I tried the patch today with the attached fixup for kzalloc on an arm machine. Also made
sure that the following options were set:

CONFIG_CPUMASK_OFFSTACK=y
CONFIG_DEBUG_PER_CPU_MAPS=y

Your patch compiles and seems to work. I exercised oprofile a bit on the arm machine with
the simple exercise.sh script.   I didn't see complaints on the /var/log/messages.

-Will