Messages in this thread | | | Subject | Re: [RFC PATCH 1/2] zap_pte_range: update addr when forcing flush after TLB batching faiure | From | Benjamin Herrenschmidt <> | Date | Sun, 02 Nov 2014 07:25:02 +1100 |
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On Sat, 2014-11-01 at 10:01 -0700, Linus Torvalds wrote: > On Wed, Oct 29, 2014 at 2:27 PM, Benjamin Herrenschmidt > <benh@kernel.crashing.org> wrote: > > > > TLB flushing is only me I think, I'll engage my brain after breakfast > > and see if is all good > > Ping? Breakfast is either long over, of you're starting to look a bit > like Mr Creosote...
Argh... dropped that ball.
> Anyway, Will, I assume this is not a correctness issue for you, just > an annoying performance issue. Right? Or is there actually some issue > with the actual range not being set to be sufficiently large?
It should be fine for us in term of correctness I think. We rely on the lazy mmu bits for batching/flushing on hash64, we use __tlb_remove_tlb_entry() for immediate flush on hash32 and the SW loaded TLB cases are pretty dumb here and should be generally unaffected.
> Also, it strikes me that I *think* that you might be able to extend > your patch to remove the whole "need_flush" field, since as far as I > can tell, "tlb->need_flush" is now equivalent to "tlb->start < > tlb->end". Of course, as long as we still require that > "need_flush_all", that doesn't actually save us any space, so maybe > it's not worth changing.
Cheers, Ben.
> Linus > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/
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