Re: [RFC PATCH] ia64: convert to dynamic percpu allocator

[Tejun Heo <tj@kernel.org>]

Tejun Heo wrote:
> * Is ai->reserved_size necessary for ia64?  This is necessary if
>   there's linking range restriction when loading modules.
>   ai->reserved_size guarantees that all static module percpu variables
>   are allocated in the first chunk which will be in the linear address
>   range and very close to __per_cpu_start.  If ai->reserved_size is
>   not set, these areas are likely to end up high in the vmalloc area.
> 
>   For example, x86_64 assumes 32bit relocations should be enough to
>   link module symbols and thus needs to set reserved_size but x86_32
>   can link to the whole 32bit space and thus can leave reserved_size
>   at zero.
> 
> * After determining the above, we can set ai->dyn_size to be
> 
>   ai->dyn_size = min(ai->unit_size - ai->static_size - ai->reserved_size,
> 		     PERCPU_DYNAMIC_RESERVE);
> 
> Would the above work?
> 
>> Even with the above PAGE_SIZE changes, the kernel still reports
>> warning from 952: WARN_ON(chunk->immutable) and then panic.
> 
> Hah... strange.  Can you please attach full boot log?  This is
> dicontig configuration, right?

Any news?

Thanks.

-- 
tejun