Re: [Bug #14467] Linker errors on ia64 with NR_CPUS=4096

Tejun Heo
2009-10-29T14:48:20Z

Christoph Lameter wrote:
>> There already are two patches for this acked by Ingo/Tejun, which Tejun is
>> going to take through his tree tomorrow.
>>
>> http://lkml.org/lkml/2009/10/27/132
>
> per cpu alloc from an atomic context without passing gfp flags through to
> the page allocator? That does not look right. Sure wish that the percpu
> allocator would be working from atomic contexts for other cases.

It's just for sched_init() which has irq off but is not really in
atomic context and does GFP_KERNEL allocations. The following comment
has been added to the first patch to explain it.

+ * allocations are done using GFP_KERNEL with pcpu_lock released. In
+ * general, percpu memory can't be allocated with irq off but
+ * irqsave/restore are still used in alloc path so that it can be used
+ * from early init path - sched_init() specifically.

Thanks.

--
tejun