* [PATCH v1 1/2] perf docs: Document bpf event modifier
@ 2024-04-16 17:00 Ian Rogers
2024-04-16 17:00 ` [PATCH v1 2/2] perf test bpf-counters: Add test for BPF " Ian Rogers
0 siblings, 1 reply; 2+ messages in thread
From: Ian Rogers @ 2024-04-16 17:00 UTC (permalink / raw
To: Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo,
Namhyung Kim, Mark Rutland, Alexander Shishkin, Jiri Olsa,
Ian Rogers, Adrian Hunter, Kan Liang, Ravi Bangoria,
Athira Rajeev, Song Liu, Thomas Richter, linux-perf-users,
linux-kernel, bpf
Document that 'b' is used as a modifier to make an event use a BPF
counter.
Fixes: 01bd8efcec44 ("perf stat: Introduce ':b' modifier")
Signed-off-by: Ian Rogers <irogers@google.com>
---
tools/perf/Documentation/perf-list.txt | 1 +
1 file changed, 1 insertion(+)
diff --git a/tools/perf/Documentation/perf-list.txt b/tools/perf/Documentation/perf-list.txt
index 3b12595193c9..6bf2468f59d3 100644
--- a/tools/perf/Documentation/perf-list.txt
+++ b/tools/perf/Documentation/perf-list.txt
@@ -71,6 +71,7 @@ counted. The following modifiers exist:
D - pin the event to the PMU
W - group is weak and will fallback to non-group if not schedulable,
e - group or event are exclusive and do not share the PMU
+ b - use BPF aggregration (see perf stat --bpf-counters)
The 'p' modifier can be used for specifying how precise the instruction
address should be. The 'p' modifier can be specified multiple times:
--
2.44.0.683.g7961c838ac-goog
^ permalink raw reply related [flat|nested] 2+ messages in thread
* [PATCH v1 2/2] perf test bpf-counters: Add test for BPF event modifier
2024-04-16 17:00 [PATCH v1 1/2] perf docs: Document bpf event modifier Ian Rogers
@ 2024-04-16 17:00 ` Ian Rogers
0 siblings, 0 replies; 2+ messages in thread
From: Ian Rogers @ 2024-04-16 17:00 UTC (permalink / raw
To: Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo,
Namhyung Kim, Mark Rutland, Alexander Shishkin, Jiri Olsa,
Ian Rogers, Adrian Hunter, Kan Liang, Ravi Bangoria,
Athira Rajeev, Song Liu, Thomas Richter, linux-perf-users,
linux-kernel, bpf
Refactor test to better enable sharing of logic, to give an idea of
progress and introduce test functions. Add test of measuring both
cycles and cycles:b simultaneously.
Signed-off-by: Ian Rogers <irogers@google.com>
---
tools/perf/tests/shell/stat_bpf_counters.sh | 75 ++++++++++++++-------
1 file changed, 52 insertions(+), 23 deletions(-)
diff --git a/tools/perf/tests/shell/stat_bpf_counters.sh b/tools/perf/tests/shell/stat_bpf_counters.sh
index 2d9209874774..61f8149d854e 100755
--- a/tools/perf/tests/shell/stat_bpf_counters.sh
+++ b/tools/perf/tests/shell/stat_bpf_counters.sh
@@ -4,21 +4,59 @@
set -e
+workload="perf bench sched messaging -g 1 -l 100 -t"
+
# check whether $2 is within +/- 20% of $1
compare_number()
{
- first_num=$1
- second_num=$2
-
- # upper bound is first_num * 120%
- upper=$(expr $first_num + $first_num / 5 )
- # lower bound is first_num * 80%
- lower=$(expr $first_num - $first_num / 5 )
-
- if [ $second_num -gt $upper ] || [ $second_num -lt $lower ]; then
- echo "The difference between $first_num and $second_num are greater than 20%."
- exit 1
- fi
+ first_num=$1
+ second_num=$2
+
+ # upper bound is first_num * 120%
+ upper=$(expr $first_num + $first_num / 5 )
+ # lower bound is first_num * 80%
+ lower=$(expr $first_num - $first_num / 5 )
+
+ if [ $second_num -gt $upper ] || [ $second_num -lt $lower ]; then
+ echo "The difference between $first_num and $second_num are greater than 20%."
+ exit 1
+ fi
+}
+
+check_counts()
+{
+ base_cycles=$1
+ bpf_cycles=$2
+
+ if [ "$base_cycles" = "<not" ]; then
+ echo "Skipping: cycles event not counted"
+ exit 2
+ fi
+ if [ "$bpf_cycles" = "<not" ]; then
+ echo "Failed: cycles not counted with --bpf-counters"
+ exit 1
+ fi
+}
+
+test_bpf_counters()
+{
+ printf "Testing --bpf-counters "
+ base_cycles=$(perf stat --no-big-num -e cycles -- $workload 2>&1 | awk '/cycles/ {print $1}')
+ bpf_cycles=$(perf stat --no-big-num --bpf-counters -e cycles -- $workload 2>&1 | awk '/cycles/ {print $1}')
+ check_counts $base_cycles $bpf_cycles
+ compare_number $base_cycles $bpf_cycles
+ echo "[Success]"
+}
+
+test_bpf_modifier()
+{
+ printf "Testing bpf event modifier "
+ stat_output=$(perf stat --no-big-num -e cycles/name=base_cycles/,cycles/name=bpf_cycles/b -- $workload 2>&1)
+ base_cycles=$(echo "$stat_output"| awk '/base_cycles/ {print $1}')
+ bpf_cycles=$(echo "$stat_output"| awk '/bpf_cycles/ {print $1}')
+ check_counts $base_cycles $bpf_cycles
+ compare_number $base_cycles $bpf_cycles
+ echo "[Success]"
}
# skip if --bpf-counters is not supported
@@ -30,16 +68,7 @@ if ! perf stat -e cycles --bpf-counters true > /dev/null 2>&1; then
exit 2
fi
-base_cycles=$(perf stat --no-big-num -e cycles -- perf bench sched messaging -g 1 -l 100 -t 2>&1 | awk '/cycles/ {print $1}')
-if [ "$base_cycles" = "<not" ]; then
- echo "Skipping: cycles event not counted"
- exit 2
-fi
-bpf_cycles=$(perf stat --no-big-num --bpf-counters -e cycles -- perf bench sched messaging -g 1 -l 100 -t 2>&1 | awk '/cycles/ {print $1}')
-if [ "$bpf_cycles" = "<not" ]; then
- echo "Failed: cycles not counted with --bpf-counters"
- exit 1
-fi
+test_bpf_counters
+test_bpf_modifier
-compare_number $base_cycles $bpf_cycles
exit 0
--
2.44.0.683.g7961c838ac-goog
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2024-04-16 17:00 ` [PATCH v1 2/2] perf test bpf-counters: Add test for BPF " Ian Rogers
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