diff options
| author | Veronika Molnarova <vmolnaro@redhat.com> | 2023-09-19 17:02:42 +0200 |
|---|---|---|
| committer | Namhyung Kim <namhyung@kernel.org> | 2023-09-21 11:53:45 -0700 |
| commit | fa52d995d1d0b64e75f63571df2e57ba22ff0cb1 (patch) | |
| tree | 74507571d6808a796cd4dc59775cbfd24a869673 /tools/perf/tests | |
| parent | e49be27e18c59639be28cd0d766caf594fe2b77f (diff) | |
perf test stat+shadow_stat.sh: Add threshold for rounding errors
The test was failing in specific scenarios due to imperfection of FP
arithmetics. The `bc` command wasn't correctly rounding the result of
division causing the failure.
Replace the `bc` with `awk` which should work with more decimal places
and add a threshold to catch any possible rounding errors. The
acceptable rounding error is set to 0.01 when the test passes with a
warning message.
Signed-off-by: Veronika Molnarova <vmolnaro@redhat.com>
Acked-by: Michael Petlan <mpetlan@redhat.com>
Link: https://lore.kernel.org/r/20230919150419.23193-1-vmolnaro@redhat.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Diffstat (limited to 'tools/perf/tests')
| -rwxr-xr-x | tools/perf/tests/shell/stat+shadow_stat.sh | 30 |
1 files changed, 24 insertions, 6 deletions
diff --git a/tools/perf/tests/shell/stat+shadow_stat.sh b/tools/perf/tests/shell/stat+shadow_stat.sh index a1918a15e36a..7d9b9d597a50 100755 --- a/tools/perf/tests/shell/stat+shadow_stat.sh +++ b/tools/perf/tests/shell/stat+shadow_stat.sh @@ -4,6 +4,8 @@ set -e +THRESHOLD=0.015 + # skip if system-wide mode is forbidden perf stat -a true > /dev/null 2>&1 || exit 2 @@ -33,10 +35,18 @@ test_global_aggr() fi # use printf for rounding and a leading zero - res=`printf "%.2f" "$(echo "scale=6; $num / $cyc" | bc -q)"` + res=`echo $num $cyc | awk '{printf "%.2f", $1 / $2}'` if [ "$ipc" != "$res" ]; then - echo "IPC is different: $res != $ipc ($num / $cyc)" - exit 1 + # check the difference from the real result for FP imperfections + diff=`echo $ipc $res $THRESHOLD | \ + awk '{x = ($1 - $2) < 0 ? ($2 - $1) : ($1 - $2); print (x > $3)}'` + + if [ $diff -eq 1 ]; then + echo "IPC is different: $res != $ipc ($num / $cyc)" + exit 1 + fi + + echo "Warning: Difference of IPC is under the threshold" fi done } @@ -67,10 +77,18 @@ test_no_aggr() fi # use printf for rounding and a leading zero - res=`printf "%.2f" "$(echo "scale=6; $num / $cyc" | bc -q)"` + res=`echo $num $cyc | awk '{printf "%.2f", $1 / $2}'` if [ "$ipc" != "$res" ]; then - echo "IPC is different for $cpu: $res != $ipc ($num / $cyc)" - exit 1 + # check difference from the real result for FP imperfections + diff=`echo $ipc $res $THRESHOLD | \ + awk '{x = ($1 - $2) < 0 ? ($2 - $1) : ($1 - $2); print (x > $3)}'` + + if [ $diff -eq 1 ]; then + echo "IPC is different: $res != $ipc ($num / $cyc)" + exit 1 + fi + + echo "Warning: Difference of IPC is under the threshold" fi done } |