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

From: Ingo Molnar
Date: Sun Oct 04 2009 - 12:49:09 EST



* Pekka Enberg <penberg@xxxxxxxxxxxxxx> wrote:

> Hi,
>
> Ingo Molnar wrote:
>> * cl@xxxxxxxxxxxxxxxxxxxx <cl@xxxxxxxxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxxxxxxxx>
>>
>> Acked-by: Ingo Molnar <mingo@xxxxxxx>
>
> 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?

Ingo
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