[PATCH] perf test: Fix test_arm_coresight.sh failures on Juno

[James Clark]

This test commonly fails on Arm Juno because the instruction interval
is large enough to miss generating any samples for Perf in system-wide
mode.

Fix this by lowering the interval until a comfortable number of Perf
instructions are generated. The test is still quick to run because only
a small amount of trace is gathered.

Before:

  sudo ./perf test coresight -vvv
  ...
  Recording trace with system wide mode
  Looking at perf.data file for dumping branch samples:
  Looking at perf.data file for reporting branch samples:
  Looking at perf.data file for instruction samples:
  CoreSight system wide testing: FAIL
  ...

After:

  sudo ./perf test coresight -vvv
  ...
  Recording trace with system wide mode
  Looking at perf.data file for dumping branch samples:
  Looking at perf.data file for reporting branch samples:
  Looking at perf.data file for instruction samples:
  CoreSight system wide testing: PASS
  ...

Signed-off-by: James Clark <james.clark@xxxxxxx>
---
 tools/perf/tests/shell/test_arm_coresight.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/tests/shell/test_arm_coresight.sh b/tools/perf/tests/shell/test_arm_coresight.sh
index e4cb4f1806ff..daad786cf48d 100755
--- a/tools/perf/tests/shell/test_arm_coresight.sh
+++ b/tools/perf/tests/shell/test_arm_coresight.sh
@@ -70,7 +70,7 @@ perf_report_instruction_samples() {
 	#   68.12%  touch    libc-2.27.so   [.] _dl_addr
 	#    5.80%  touch    libc-2.27.so   [.] getenv
 	#    4.35%  touch    ld-2.27.so     [.] _dl_fixup
-	perf report --itrace=i1000i --stdio -i ${perfdata} 2>&1 | \
+	perf report --itrace=i20i --stdio -i ${perfdata} 2>&1 | \
 		egrep " +[0-9]+\.[0-9]+% +$1" > /dev/null 2>&1
 }
 
-- 
2.28.0