Re: [RFC PATCH 0/6] target/ppc: Improve 4xx and 440 tlbwe

[BALATON Zoltan]

On Fri, 22 Dec 2023, BALATON Zoltan wrote:
> On Wed, 15 Nov 2023, BALATON Zoltan wrote:
> > On Tue, 14 Nov 2023, Nicholas Piggin wrote:
> > > Well I split out these patches and looked a bit closer and added
> > > a few more things.
> > >
> > > I think it may be a bit too much to do the optimisations for
> > > this release, because 4xx TLB flushing has some quirks too so
> > > it's not just simple implementation of 4xx scheme in 440. We
> > > could try for next time.
> > >
> > > The bug fix patch 1 maybe we should do. We haven't been able to
> > > confirm it fixes anything but there was mention of occasional
> > > random crashes.
> >
> > I did some quick testing of this series and found that patch 1 alone makes 
> > it slower but not known to fix any issue so I'd say don't commit just this 
> > patch without the rest. The current version works enoigh so we can live 
> > with that until the next version. With the other patches it's faster and 
> > the last patch does make a difference, it makes it a bit faster. I did not 
> > record the numbers and only did one measurement so it's only approximate 
> > but unless you plan to take the whole series now then keep patch 1 for next 
> > devel cycle as well.
>
> Can this series be merged now? Too bad it did not make it in 8.2 but at least 
> make sure it won't miss 9.0.

Ping?

Regards,
BALATON Zoltan

> > > Thanks,
> > > Nick
> > >
> > > Nicholas Piggin (6):
> > >  target/ppc: Fix 440 tlbwe TLB invalidation gaps
> > >  target/ppc: Factor out 4xx ppcemb_tlb_t flushing
> > >  target/ppc: 4xx don't flush TLB for a newly written software TLB entry
> > >  target/ppc: 4xx optimise tlbwe_lo TLB flushing
> > >  target/ppc: 440 optimise tlbwe TLB flushing
> > >  target/ppc: optimise ppcemb_tlb_t flushing
> > >
> > > target/ppc/mmu_helper.c | 105 +++++++++++++++++++++++-----------------
> > > 1 file changed, 61 insertions(+), 44 deletions(-)