From: James Clark <james.clark@linaro.org>
Date: Tue, 9 Jun 2026 14:40:18 +0000 (+0100)
Subject: perf test cs-etm: Reduce snapshot size
X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=c13fe5f07518526416284d63acc1c50af88b03e3;p=thirdparty%2Fkernel%2Flinux.git

perf test cs-etm: Reduce snapshot size

The default buffer size for root is 4MB which is very slow to decode. We
only need a few KB to verify that the dd process is hit so reduce the
size to 128KB.

Reviewed-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: James Clark <james.clark@linaro.org>
Cc: Amir Ayupov <aaupov@meta.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mike Leach <mike.leach@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paschalis Mpeis <Paschalis.Mpeis@arm.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---

diff --git a/tools/perf/tests/shell/test_arm_coresight.sh b/tools/perf/tests/shell/test_arm_coresight.sh
index 8ed2c934c87d0..da2f599393e2e 100755
--- a/tools/perf/tests/shell/test_arm_coresight.sh
+++ b/tools/perf/tests/shell/test_arm_coresight.sh
@@ -156,7 +156,7 @@ arm_cs_etm_system_wide_test() {
 
 arm_cs_etm_snapshot_test() {
 	echo "Recording trace with snapshot mode"
-	perf record -o ${perfdata} -e cs_etm// -S \
+	perf record -o ${perfdata} -e cs_etm// -S -m,128K \
 		-- dd if=/dev/zero of=/dev/null > /dev/null 2>&1 &
 	PERFPID=$!