perf test shell arm_coresight: Increase buffer size for Coresight basic tests

[ Upstream commit 10b6ee3b59 ]

These tests record in a mode that includes kernel trace but look for
samples of a userspace process. This makes them sensitive to any kernel
compilation options that increase the amount of time spent in the
kernel. If the trace buffer is completely filled before userspace is
reached then the test will fail. Double the buffer size to fix this.

The other tests in the same file aren't sensitive to this for various
reasons, for example the iterate devices test filters by userspace trace
only. But in order to keep coverage of all the modes, increase the
buffer size rather than filtering by userspace for the basic tests.

Fixes: d1efa4a0a6 ("perf cs-etm: Add separate decode paths for timeless and per-thread modes")
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: James Clark <james.clark@arm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20240326113749.257250-1-james.clark@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

tools/perf/tests/shell/test_arm_coresight.sh

@@ -188,7 +188,7 @@ arm_cs_etm_snapshot_test() {
 
 arm_cs_etm_basic_test() {
 	echo "Recording trace with '$*'"
-	perf record -o ${perfdata} "$@" -- ls > /dev/null 2>&1
+	perf record -o ${perfdata} "$@" -m,8M -- ls > /dev/null 2>&1
 
 	perf_script_branch_samples ls &&
 	perf_report_branch_samples ls &&