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

From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: Leo Yan <leo.yan@linaro.org>
Cc: James Clark <james.clark@arm.com>,
	coresight@lists.linaro.org, denik@chromium.org,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Mike Leach <mike.leach@linaro.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	Mark Rutland <mark.rutland@arm.com>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Jiri Olsa <jolsa@kernel.org>, Namhyung Kim <namhyung@kernel.org>,
	Ian Rogers <irogers@google.com>,
	Adrian Hunter <adrian.hunter@intel.com>,
	John Garry <john.g.garry@oracle.com>,
	Will Deacon <will@kernel.org>,
	linux-arm-kernel@lists.infradead.org,
	linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 0/4] perf cs-etm: Track exception level
Date: Tue, 6 Jun 2023 15:07:32 -0300	[thread overview]
Message-ID: <ZH915HtVcUnLxHsd@kernel.org> (raw)
In-Reply-To: <20230606004648.GB18315@leoy-huanghe>

Em Tue, Jun 06, 2023 at 08:46:48AM +0800, Leo Yan escreveu:
> 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.

Ok, left just the first patch on my local perf-tools-next branch, will
go public when tested.

- Arnaldo