From 4aeacf722cee26a3f88ab7f631c9ab9ba6ecdb49 Mon Sep 17 00:00:00 2001 From: Marcelo Tosatti Date: Thu, 1 Feb 2024 14:50:54 -0300 Subject: [PATCH 2/2] rt-tests: oslat: convert to nanoseconds correctly With buckets of size 1us, accounting for measurements in the [1ns, 999ns] range are done to the 2us bucket (while they should be accounted in the 1us bucket): 001 (us): 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 002 (us): 41916187 41937649 41938461 42029055 ... 003 (us): 969 985 958 972 964 986 970 961 973 ... Fix this by doing a plain cycles -> nanoseconds convertion: 001 (us): 43287555 43086678 43087427 43109974 ... 002 (us): 983 987 985 975 982 960 993 961 992 ... 003 (us): 9 6 7 13 9 22 3 21 3 3 8 8 10 11 3 55 Signed-off-by: Marcelo Tosatti Reported-by: Chuck Newman Signed-off-by: John Kacur --- src/oslat/oslat.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/oslat/oslat.c b/src/oslat/oslat.c index e398f205b40a..0863297f2cf1 100644 --- a/src/oslat/oslat.c +++ b/src/oslat/oslat.c @@ -334,7 +334,7 @@ static void insert_bucket(struct thread *t, stamp_t value) uint64_t extra; double us; - lat = (value * g.unit_per_us + t->counter_mhz - 1) / t->counter_mhz; + lat = (value * g.unit_per_us) / t->counter_mhz; us = (double)lat / g.unit_per_us; if (!g.preheat && g.trace_threshold && us >= g.trace_threshold) { char *line = "%s: Trace threshold (%d us) triggered on cpu %d with %.*f us!\n"; -- 2.43.0