Re: [PATCH 6/6] perf: Add dcacheline sort

Stephane Eranian
2014-05-16T16:27:39Z

On Fri, May 16, 2014 at 6:24 PM, Don Zickus <dzickus@redhat.com> wrote:
> On Fri, May 16, 2014 at 06:02:43PM +0200, Stephane Eranian wrote:
>> On Fri, May 16, 2014 at 5:59 PM, Peter Zijlstra <peterz@infradead.org> wrote:
>> > On Fri, May 16, 2014 at 04:09:59PM +0200, Stephane Eranian wrote:
>> >> > +#define CACHE_LINESIZE 64
>> >> I had something similar to your patch here in my original series for
>> >> perf mem, but I never pushed it.
>> >> I think this is a useful feature to have.
>> >> However, I don't think you can hardcode the cache line size to 64.
>> >> This is generic
>> >> code. There may be architectures where the line size is different from 64.
>> >> So I think you should add an option to change the default line size or provide
>> >> an arch-specific definition.
>> >
>> > # cat /sys/devices/system/cpu/cpu0/cache/index0/coherency_line_size
>> > 64
>> Excellent, then we should use that!
>
> Would it make sense to create an accessory function that sets the size in
> util/cpumap.c and provides it as an inline from util/cpumap.h?
>
I am fine with it.