Re: [RFC] MIPS: Add cacheinfo support

[Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>]

On 12/12/2016 10:24 AM, Florian Fainelli wrote:
>
> What Justin's patch is about is not so much about providing hints to
> user-space to bypass the kernel's own management of caches, (even though
> that has been used as an argument by the original introduction of
> cacheinfo), but more to provide some information to user-space about the
> cache topology and hierarchy.

I missed that, if it is for information purpose only, then it is OK.

>
> Even though this is limited information this is still helpful to
> applications like lshw and others out there.
>
> What would be needed from your perspective to get cacheinfo added to
> MIPS, shall we go back and address your initial comment about all the
> little details about coherency, snooping and re-filling strategy?

It depends. Initially, I thought Justin wants to replace 
arch/mips/mm/c-XXX.c with some universal approach and listed the missed 
stuff for that (I actually missed some more points in that list).

But for information purpose I don't have any more addition to Justin's 
patch... may be the coherency status, it has impact on performance: 
coherency of L1D->L2, L2->memory and L1I->L1D/L2.


- Leonid