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9c33441418
When BPF collects the stats for the latency in usec, it first divides
the time by 1000. But that means it would have 0 if the delta is small
and won't update the total time properly.
Let's keep the stats in nsec always and adjust to usec before printing.
Before:
$ sudo ./perf ftrace latency -ab -T mutex_lock --hide-empty -- sleep 0.1
# DURATION | COUNT | GRAPH |
0 - 1 us | 765 | ############################################# |
1 - 2 us | 10 | |
2 - 4 us | 2 | |
4 - 8 us | 5 | |
# statistics (in usec)
total time: 0 <<<--- (here)
avg time: 0
max time: 6
min time: 0
count: 782
After:
$ sudo ./perf ftrace latency -ab -T mutex_lock --hide-empty -- sleep 0.1
# DURATION | COUNT | GRAPH |
0 - 1 us | 880 | ############################################ |
1 - 2 us | 13 | |
2 - 4 us | 8 | |
4 - 8 us | 3 | |
# statistics (in usec)
total time: 268 <<<--- (here)
avg time: 0
max time: 6
min time: 0
count: 904
Tested-by: Athira Rajeev <atrajeev@linux.ibm.com>
Cc: Gabriele Monaco <gmonaco@redhat.com>
Link: https://lore.kernel.org/r/20250227191223.1288473-1-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
4.1 KiB
4.1 KiB