Re: [PATCH 2/4] ia64: allocate percpu area for cpu0 like percpu areasfor other cpus

[Tejun Heo]

Christoph Lameter wrote:
> On Wed, 23 Sep 2009, Tejun Heo wrote:
> 
>> any special handling.  What problems are you seeing?
> 
> per cpu variable access on IA64 does not use the percpu_offset for the
> calculation of the current per cpu data area. Its using a virtual mapping.
> 
> How does the new percpu allocator support this? Does it use different
> methods of access for static and dynamic percpu access?

That's only when __ia64_per_cpu_var() macro is used in arch code which
always references static perpcu variable in the kernel image which
falls inside PERCPU_PAGE_SIZE.  For everything else, __my_cpu_offset
is defined as __ia64_per_cpu_var(local_per_cpu_offset) and regular
pointer offsetting is used.

Thanks.

-- 
tejun
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/