Re: [PATCH v1 0/3] coresight: Fix for snapshot mode

From: Denis Nikitin <denik@google.com>
To: Leo Yan <leo.yan@linaro.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>,
	Mathieu Poirier <mathieu.poirier@linaro.org>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Mike Leach <mike.leach@linaro.org>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	John Garry <john.garry@huawei.com>, Will Deacon <will@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>, Jiri Olsa <jolsa@redhat.com>,
	Namhyung Kim <namhyung@kernel.org>,
	Daniel Kiss <daniel.kiss@arm.com>,
	Coresight ML <coresight@lists.linaro.org>,
	linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	linux-perf-users@vger.kernel.org
Subject: Re: [PATCH v1 0/3] coresight: Fix for snapshot mode
Date: Wed, 9 Jun 2021 23:43:15 -0700	[thread overview]
Message-ID: <CAOYpmdEvkSZaei-_SWrUC4YJ7rOUOoOaxM7+qc6dw=P+b_ivgA@mail.gmail.com> (raw)
In-Reply-To: <20210528161552.654907-1-leo.yan@linaro.org>

Hi Leo,

On Fri, May 28, 2021 at 9:16 AM Leo Yan <leo.yan@linaro.org> wrote:
>
> This patch series is to correct the pointer usages for the snapshot
> mode.
>
> Patch 01 allows the AUX trace in the free run mode and only syncs the
> AUX ring buffer when taking snapshot.
>
> Patch 02 is to polish code, it removes the redundant header maintained
> in tmc-etr driver and directly uses pointer perf_output_handle::head.
>
> Patch 03 removes the callback cs_etm_find_snapshot() which wrongly
> calculates the buffer headers; we can simply use the perf's common
> function __auxtrace_mmap__read() for headers calculation.
>
> This patch can be cleanly applied on the mainline kernel with:
>
>   commit 97e5bf604b7a ("Merge branch 'for-5.13-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu")
>
> And it has been tested on Arm64 Juno board.

I have verified the patches on Chrome OS Trogdor device.
They fixed the problem discussed in
https://lists.linaro.org/pipermail/coresight/2021-May/006411.html.

Tested-by: Denis Nikitin <denik@chromium.org>

Thanks,
Denis

>
>
> Leo Yan (3):
>   coresight: etm-perf: Correct buffer syncing for snapshot
>   coresight: tmc-etr: Use perf_output_handle::head for AUX ring buffer
>   perf cs-etm: Remove callback cs_etm_find_snapshot()
>
>  .../hwtracing/coresight/coresight-etm-perf.c  |  30 +++-
>  .../hwtracing/coresight/coresight-etm-perf.h  |   2 +
>  .../hwtracing/coresight/coresight-tmc-etr.c   |  10 +-
>  tools/perf/arch/arm/util/cs-etm.c             | 133 ------------------
>  4 files changed, 32 insertions(+), 143 deletions(-)
>
> --
> 2.25.1
>