rt-tests: oslat: convert to nanoseconds correctly
PATCH 1/1 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 55Signed-off-by Marcelo Tosatti <[email protected]>
Reported-by Chuck Newman <[email protected]>
src/oslat/oslat.c +1 -1
@@ -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" ;
Quoted 27 lines · Marcelo Tosatti
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 55Signed-off-by Marcelo Tosatti <[email protected]>Reported-by Chuck Newman <[email protected]>src/oslat/oslat.c +0
-0
src/oslat/oslat.c static void insert_bucket(struct thread *t, stamp_t value) · line 340
Quoted 8 lines
src/oslat/oslat.c +1
-1@@ -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" ;
Signed-off-by John Kacur <[email protected]>