Subject: Re: [PATCH 3/4] powerpc/mm/radix: Avoid flushing the PWC on every flush_tlb_range

From: Benjamin Herrenschmidt <[email-masked]>
Date: Fri, 14 Jul 2017 16:22:44 +1000

On Fri, 2017-07-14 at 11:14 +0530, Aneesh Kumar K.V wrote:
> > +     pid = mm ? mm->context.id : 0;
> > +     if (unlikely(pid == MMU_NO_CONTEXT))
> > +             goto no_context;
> > +
> > +     /* 4k page size, just blow the world */
> > +     if (PAGE_SIZE == 0x1000) {
> > +             radix__flush_all_mm(mm);
> > +             return;
> > +     }
> 
> What is special here ? because it is 4096 tlb flushes ?

Yes, keeping in line with the existing logic in flush_tlb_pages(), more
than 32, do a full flush.

Cheers,
Ben.