[PATCH 0/4] perf cs-etm: Track exception level

Leo Yan leo.yan at linaro.org
Mon Jun 5 17:46:48 PDT 2023


Hi Arnaldo,

On Mon, Jun 05, 2023 at 04:44:45PM -0300, Arnaldo Carvalho de Melo wrote:
> Em Wed, May 24, 2023 at 02:19:54PM +0100, James Clark escreveu:
> > Some fixes to support an issue reported by Denis Nikitin where decoding
> > trace that contains different EL1 and EL2 kernels can crash or go into
> > an infinite loop because the wrong kernel maps are used for the decode.
> > 
> > This still doesn't support distinguishing guest and host userspace,
> > we'd still have to fix the timestamps and do a bit more work to
> > correlate that. And I've removed PERF_RECORD_MISC_HYPERVISOR as a
> > possible outcome of cs_etm__cpu_mode(). As far as I know this could
> > never have been returned anyway because machine__is_host(machine) was
> > always true due to session.machines.host being hard coded. And I'm not
> > sure of the relevance of the difference between PERF_RECORD_MISC_KERNEL
> > and PERF_RECORD_MISC_HYPERVISOR in this scenario.
> > 
> > The first commit is a tidy up, second fixes a bug that I found when
> > comparing the exception level and thread of branch records, the third
> > is the main fix, and the last commit is some extra error checking. 
> > 
> > Applies to acme/perf-tools (4e111f0cf0)
> 
> So there seems to be agreement the first two patches can be applied? May
> I go ahead and do that now?

Could you pick up the first patch in this series?

I would like ask James to refine a bit for the second patch.

Thanks,
Leo



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