Re: [GIT RFC] percpu: use dynamic percpu allocator as the defaultpercpu allocator

[Tejun Heo]

Hello,

Martin Schwidefsky wrote:
>> Also, there is no guarantee that the offset from dynamic allocator
>> will fall in the same 4G.  There is reserve mechanism for static ones
>> for archs which need it but for dynamic ones, the offset can be any
>> value.
> 
> If we map the modules with a 4GB distance to the main kernel image then
> we don't have to worry about the offsets anymore. The compiler could
> just use LARL to get the address of the static per-cpu variables and
> SHIFT_PERCPU_PTR could be a RELOC_HIDE.

Ah... okay.  Great.  No more GOTENT trick for static ones and for
dynamic ones the compiler will generate indirection.

> It just that the remapping we need to do is sooo icky ..

Fingers and toes crossed.  It would improve general percpu access
performance too.

Thanks.

-- 
tejun
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