Re: [PATCH v3 0/4] Add BHRB Facility Support

[Nicholas Piggin]

On Tue Nov 28, 2023 at 6:51 AM AEST, Miles Glenn wrote:
> On Wed, 2023-10-18 at 10:59 -0500, Miles Glenn wrote:
> > On Thu, 2023-10-19 at 01:06 +1000, Nicholas Piggin wrote:
> > > On Tue Sep 26, 2023 at 3:43 AM AEST, Glenn Miles wrote:
> > > > This is a series of patches for adding support for the Branch
> > > > History
> > > > Rolling Buffer (BHRB) facility.  This was added to the Power ISA
> > > > starting with version 2.07.  Changes were subsequently made in
> > > > version
> > > > 3.1 to limit BHRB recording to instructions run in problem state
> > > > only
> > > > and to add a control bit to disable recording (MMCRA[BHRBRD]).
> > > > 
> > > > Version 3 of this series disables branch recording on P8 and P9
> > > > due
> > > > to a drop in performance caused by recording branches outside of
> > > > problem state.
> > > 
> > > Thanks for these, they all look good to me.
> > > 
> > > With P10 CPU, Linux perf branch recording appears to work with this
> > > series, and I confirmed that Linux does disable BHRB in MMCRA at
> > > boot, so it should not take the performance hit.
> > > 
> > > It had a couple of compile bugs, no matter I fixed them, but I
> > > often
> > > trip overppc32 and user-mode when working on TCG too, so building
> > > with --target-list including ppc64-softmmu,ppc-softmmu,
> > > ppc64-linux-user,ppc64le-linux-user,ppc-linux-user is good to catch
> > > those.
> > > 
> > > Thanks,
> > > Nick
> > > 
> > 
> > Thanks, Nick.  I'll have to remember that for next time!
> > 
> > Glenn
> > 
>
> Hi Nick,
>
> Is there anything else you need me to do for this series to be merged?

Hey Glenn,

No, sorry I just missed this cycle. I have it queued up, it'll have to
go in after 8.2 release.

Thanks,
Nick