[PATCH 1/8] test: Allow aggpercpu test to omit some CPUs

eugene.loh
2024-06-04T18:00:15Z

From: Eugene Loh <eugene.loh@oracle.com>

The aggpercpu test uses profile-* to fire aggregations on every CPU.
But whether for good (offline CPUs) or bad (unreliable probe) reasons,
a CPU might not aggregate any values.

Allow this test to skip over such CPUs. That is, while a BPF agg map
might have the correct default value for the aggregation function, it
may not see any anticipated data. The quality of profile-* probes
should be checked by a different test.

Also, when computing avg() and stddev() in the awk check program,
truncate results to ints more often to mimic the algorithms in DTrace
for more robust checks.

Signed-off-by: Eugene Loh <eugene.loh@oracle.com>
---
test/unittest/aggs/tst.aggpercpu.sh | 62 +++++++++++++++++++++--------
1 file changed, 45 insertions(+), 17 deletions(-)

diff --git a/test/unittest/aggs/tst.aggpercpu.sh b/test/unittest/aggs/tst.aggpercpu.sh
index be74890a..6092bd17 100755
--- a/test/unittest/aggs/tst.aggpercpu.sh
+++ b/test/unittest/aggs/tst.aggpercpu.sh
@@ -46,7 +46,8 @@ fi
awk '
# The expected value for the aggregation is aggval.
# The expected value on a CPU is (m * cpu + b).
- function check(label, aggval, m, b) {
+ # The default value on a CPU that did not fire is defval.
+ function check(label, aggval, m, b, defval) {
# Check the aggregation over all CPUs.
getline;
print "check:", $0;
@@ -54,12 +55,38 @@ awk '

# Check the per-CPU values.
for (i = 1; i <= ncpu; i++) {
- getline;
- print "check:", $0;
- if (match($0, "^ \\[CPU ") != 1 ||
- strtonum($2) != cpu[i] ||
- strtonum($3) != m * cpu[i] + b)
- printf("ERROR: %s, agg per cpu %d, line: %s\n", label, cpu[i], $0);
+ do {
+ getline;
+ print "check:", $0;
+
+ # pass is +1 for pass, -1 for error, 0 for skip CPU
+ pass = 0;
+
+ if (match($0, "^ \\[CPU ") != 1) {
+ print "ERROR: no CPU to read"
+ pass = -1;
+ } else if (strtonum($2) > cpu[i]) {
+ print "ERROR: skipped over expected CPU"
+ pass = -1;
+ } else if (strtonum($2) == cpu[i]) {
+ if (strtonum($3) != m * cpu[i] + b) {
+ print "ERROR: wrong value"
+ pass = -1;
+ } else {
+ # right value
+ pass = +1;
+ }
+ } else if ($3 != defval) {
+ print "ERROR: wrong default value"
+ pass = -1;
+ } else {
+ # skip over CPU that apparently did not fire
+ pass = 0;
+ }
+
+ if (pass == -1)
+ printf("ERROR: %s, agg per cpu %d, line: %s\n", label, cpu[i], $0);
+ } while (pass == 0);
}
}

@@ -99,13 +126,14 @@ awk '
{
# First we finish computing our estimates for avg and stddev.
# (The other results require no further action.)
+ # (We keep truncating to ints to mimic DTrace algorithms.)

- xavg /= xcnt;
+ xavg /= xcnt; xavg = int(xavg);

- xstm /= xcnt;
- xstd /= xcnt;
+ xstm /= xcnt; xstm = int(xstm);
+ xstd /= xcnt; xstd = int(xstd);
xstd -= xstm * xstm;
- xstd = int(sqrt(xstd));
+ xstd = sqrt(xstd); xstd = int(xstd);

# Sort the cpus.

@@ -113,12 +141,12 @@ awk '

# Now read the results and compare.

- check("cnt", xcnt, 0, 1);
- check("avg", xavg, 10, 3);
- check("std", xstd, 0, 0);
- check("min", xmin, 30, -10);
- check("max", xmax, 40, -15);
- check("sum", xsum, 50, 0);
+ check("cnt", xcnt, 0, 1, "0");
+ check("avg", xavg, 10, 3, "0");
+ check("std", xstd, 0, 0, "0");
+ check("min", xmin, 30, -10, "9223372036854775807");
+ check("max", xmax, 40, -15, "-9223372036854775808");
+ check("sum", xsum, 50, 0, "0");

printf("done\n");
}
--
2.18.4