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

[Kris Van Hees]

On Tue, Jun 04, 2024 at 02:00:01PM -0400, eugene.loh at oracle.com wrote:
> From: Eugene Loh <eugene.loh at 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 at oracle.com>

Reviewed-by: Kris Van Hees <kris.van.hees at 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
>