Re: [PATCH v2] arch/cacheflush: Introduce flush_all_caches()

[Davidlohr Bueso]

On Sun, 21 Aug 2022, Christoph Hellwig wrote:

> On Fri, Aug 19, 2022 at 10:10:24AM -0700, Davidlohr Bueso wrote:
> > index b192d917a6d0..ac4d4fd4e508 100644
> > --- a/arch/x86/include/asm/cacheflush.h
> > +++ b/arch/x86/include/asm/cacheflush.h
> > @@ -10,4 +10,8 @@
> >
> >  void clflush_cache_range(void *addr, unsigned int size);
> >
> > +/* see comments in the stub version */
> > +#define flush_all_caches() \
> > +	do { wbinvd_on_all_cpus(); } while(0)
>
> Yikes.  This is just a horrible, horrible name and placement for a bad
> hack that should have no generic relevance.

Why does this have no generic relevance? There's already been discussions
on how much wbinv is hated[0].

> Please fix up the naming to make it clear that this function is for a
> very specific nvdimm use case, and move it to a nvdimm-specific header
> file.

Do you have any suggestions for a name? And, as the changelog describes,
this is not nvdimm specific anymore, and the whole point of all this is
volatile memory components for cxl, hence nvdimm namespace is bogus.

[0] https://lore.kernel.org/all/Yvtc2u1J%2Fqip8za9@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/

Thanks,
Davidlohr