[PATCH v1 1/9] selftests/resctrl: Verify all RMIDs count together

Peter Newman
2023-04-21T14:18:03Z

AMD CPUs in particular implement fewer monitors than RMIDs, so add a
test case to see if a large number of monitoring groups can be measured
together.

Signed-off-by: Peter Newman <peternewman@google.com>
---
tools/testing/selftests/resctrl/test_rmids.sh | 93 +++++++++++++++++++
1 file changed, 93 insertions(+)
create mode 100755 tools/testing/selftests/resctrl/test_rmids.sh

diff --git a/tools/testing/selftests/resctrl/test_rmids.sh b/tools/testing/selftests/resctrl/test_rmids.sh
new file mode 100755
index 000000000000..475e69c0217e
--- /dev/null
+++ b/tools/testing/selftests/resctrl/test_rmids.sh
@@ -0,0 +1,93 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+cd /sys/fs/resctrl
+
+grep -q mbm_total_bytes info/L3_MON/mon_features || {
+ echo "MBM required"
+ exit 4
+}
+
+which perf > /dev/null || {
+ echo "perf tool required"
+ exit 4
+}
+
+num_rmids=$(cat info/L3_MON/num_rmids)
+
+count=0
+
+result=0
+
+# use as many RMIDs as possible, up to the number of RMIDs
+for i in `seq $num_rmids`; do
+ mkdir mon_groups/_test_m$((count+1)) 2> /dev/null || break
+ if [[ -d mon_groups/_test_m$((count+1))/mon_data ]]; then
+ count=$((count+1))
+ else
+ break;
+ fi
+done
+
+echo "Created $count monitoring groups."
+
+if [[ $count -eq 0 ]]; then
+ echo "need monitoring groups to continue."
+ exit 4
+fi
+
+declare -a bytes_array
+
+unavailable=0
+unavailable0=0
+
+for i in `seq $count`; do
+ bytes_array[$i]=$(cat mon_groups/_test_m${i}/mon_data/mon_L3_00/mbm_total_bytes)
+
+ if [[ "${bytes_array[$i]}" = "Unavailable" ]]; then
+ unavailable0=$((unavailable0 + 1))
+ fi
+done
+
+for i in `seq $count`; do
+ echo $$ > mon_groups/_test_m${i}/tasks
+ taskset 0x1 perf bench mem memcpy -s 100MB -f default > /dev/null
+done
+echo $$ > tasks
+
+# zero non-integer values
+declare -i bytes bytes0
+
+success_count=0
+
+for i in `seq $count`; do
+ raw_bytes=$(cat mon_groups/_test_m${i}/mon_data/mon_L3_00/mbm_total_bytes)
+ raw_bytes0=${bytes_array[$i]}
+
+ # coerce the value to an integer for math
+ bytes=$raw_bytes
+ bytes0=$raw_bytes0
+
+ echo -n "g${i}: mbm_total_bytes: $raw_bytes0 -> $raw_bytes"
+
+ if [[ "$raw_bytes" = "Unavailable" ]]; then
+ unavailable=$((unavailable + 1))
+ fi
+
+ if [[ $bytes -gt $bytes0 ]]; then
+ success_count=$((success_count+1))
+ echo ""
+ else
+ echo " (FAIL)"
+ result=1
+ fi
+done
+
+first=$((count-unavailable0))
+second=$((count-unavailable))
+echo "$count groups, $first returned counts in first pass, $second in second"
+echo "successfully measured bandwidth from ${success_count}/${count} groups"
+
+rmdir mon_groups/_test_m*
+
+exit $result
--
2.40.0.634.g4ca3ef3211-goog