[PATCH] powerpc/mm: Use tlbiel only if we ever ran on the current cpu

[Aneesh Kumar K.V]

Balbir Singh <bsingharora at gmail.com> writes:

> On 24/10/16 14:20, Aneesh Kumar K.V wrote:
>> Before this patch, we used tlbiel, if we ever ran only on this core.
>> That was mostly derived from the nohash usage of the same. But the
>> ISA 3.0 clarifies tlbiel such that
>> 
>> "All TLB entries that have all of the following properties are made
>> invalid on the thread executing the tlbiel instruction"
>> 
>> Hence use tlbiel, if we only ever ran on just the current cpu.
>> 
>
> Could you clarify the impact. The impact I see is that it could
> lead to us thinking we invalidated the TLB across the core whereas
> we did it only on the current thread? This could leave others threads
> in the same core with invalid TLB's, if cpumask reported we ran on
> other threads in the same core?

Correct.

-aneesh