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Subject: Re: [PATCH 3/4] powerpc/mm/radix: Avoid flushing the PWC on every
 flush_tlb_range
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>,
 linuxppc-dev@lists.ozlabs.org
Cc: npiggin@gmail.com
Date: Fri, 14 Jul 2017 16:22:44 +1000
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References: <20170714015258.7933-1-benh@kernel.crashing.org>
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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.