Re: [this_cpu_xx V4 02/20] this_cpu: X86 optimized this_cpu operations

[Pekka Enberg <penberg@cs.helsinki.fi>]

Hi Ingo,

Ingo Molnar wrote:
> * Pekka Enberg <penberg@cs.helsinki.fi> wrote:
> 
>> Hi,
>>
>> Ingo Molnar wrote:
>>> * cl@linux-foundation.org <cl@linux-foundation.org> wrote:
>>>
>>>> Basically the existing percpu ops can be used for this_cpu variants  
>>>> that allow operations also on dynamically allocated percpu data.  
>>>> However, we do not pass a reference to a percpu variable in. Instead 
>>>> a dynamically or statically allocated percpu variable is provided.
>>>>
>>>> Preempt, the non preempt and the irqsafe operations generate the same 
>>>> code. It will always be possible to have the requires per cpu  
>>>> atomicness in a single RMW instruction with segment override on x86.
>>>>
>>>> 64 bit this_cpu operations are not supported on 32 bit.
>>>>
>>>> Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
>>> Acked-by: Ingo Molnar <mingo@elte.hu>
>> I haven't looked at the series in detail but AFAICT the SLUB patches 
>> depend on the x86 ones. Any suggestions how to get all this into 
>> linux-next? Should I make a topic branch in slab.git on top of -tip or 
>> something?
> 
> I'd suggest to keep these patches together in the right topical tree: 
> Tejun's percpu tree. Any problem with that approach?

I'm fine with that. Just wanted to make sure who is taking the patches 
and if I should pick any of them up. We can get some conflicts between 
the per-cpu tree and slab.git if new SLUB patches get merged but that's 
probably not a huge problem.

			Pekka