Re: [PATCH 04/12] perf test: Add beginning of test infra + test to exercise coresight

From: James Clark <james.clark@arm.com>
To: carsten.haitzler@foss.arm.com, linux-kernel@vger.kernel.org
Cc: coresight@lists.linaro.org, inux-perf-users@vger.kernel.org,
	acme@kernel.org, mike.leach@linaro.org,
	suzuki K Poulose <suzuki.poulose@arm.com>,
	Leo Yan <leo.yan@linaro.org>,
	Mathieu Poirier <mathieu.poirier@linaro.org>,
	Anshuman Khandual <anshuman.khandual@arm.com>
Subject: Re: [PATCH 04/12] perf test: Add beginning of test infra + test to exercise coresight
Date: Wed, 19 Jan 2022 16:58:48 +0000	[thread overview]
Message-ID: <a7f01bb8-9b5a-6121-5fcc-38ddffa633fe@arm.com> (raw)
In-Reply-To: <20211215160403.69264-4-carsten.haitzler@foss.arm.com>

On 15/12/2021 16:03, carsten.haitzler@foss.arm.com wrote:
> From: Carsten Haitzler <carsten.haitzler@arm.com>
> 
> This adds the initial test harness to run perf record and examine the
> resuling output when coresight is enabled on arm64 and check the
> resulting quality of the output as part of perf test.
> 
> Signed-off-by: Carsten Haitzler <carsten.haitzler@arm.com>
> ---
[...]
> diff --git a/tools/perf/tests/shell/coresight_asm_pure_loop.sh b/tools/perf/tests/shell/coresight_asm_pure_loop.sh
> new file mode 100755
> index 000000000000..542d4a37e349
> --- /dev/null
> +++ b/tools/perf/tests/shell/coresight_asm_pure_loop.sh
> @@ -0,0 +1,18 @@
> +#!/bin/sh -e
> +# Coresight / ASM Pure Loop
> +
> +# SPDX-License-Identifier: GPL-2.0
> +# Carsten Haitzler <carsten.haitzler@arm.com>, 2021
> +
> +TEST="asm_pure_loop"
> +. $(dirname $0)/lib/coresight.sh
> +ARGS=""
> +DATV="out"
> +DATA="$DATD/perf-$TEST-$DATV.data"
> +
> +perf record $PERFRECOPT -o "$DATA" "$BIN" $ARGS
> +
> +perf_dump_aux_verify "$DATA" 2601 334 334
> +
> +err=$?
> +exit $err
> diff --git a/tools/perf/tests/shell/lib/coresight.sh b/tools/perf/tests/shell/lib/coresight.sh
> new file mode 100644
> index 000000000000..cd6c1283e6f5
> --- /dev/null
> +++ b/tools/perf/tests/shell/lib/coresight.sh
> @@ -0,0 +1,130 @@
> +# SPDX-License-Identifier: GPL-2.0
> +# Carsten Haitzler <carsten.haitzler@arm.com>, 2021
> +
> +# This is sourced from a driver script so no need for #!/bin... etc. at the
> +# top - the assumption below is that it runs as part of sourcing after the
> +# test sets up some basic env vars to say what it is.
> +
> +# perf record options for the perf tests to use
> +PERFRECMEM="-m ,128M"
> +PERFRECOPT="$PERFRECMEM -e cs_etm//u"
> +
> +# These tests need to be run as root or coresight won't allow large buffers
> +# and will not collect proper data

I've somewhat fixed this with the change 7cc9680c4be. Can you re-test that it
works without sudo? I think it's best to avoid it unless necessary and the
cs_etm//u seems to suggest that it's not necessary.

If 'proper data' can't be collected without root then it seems more like the
tests have found a real issue to fix rather than something to be worked around.

James