realtime-tests/rt-tests-oslat-convert-to-nanoseconds-correctly.patch
John Kacur 62d150d0fa oslat: correct spelling of Mhz to MHz
oslat: Fix conversion to nanoseconds for 1us bucket
Resolves: RHEL-23909
Signed-off-by: John Kacur <jkacur@redhat.com>
2024-02-05 12:22:30 -05:00

43 lines
1.5 KiB
Diff

From 4aeacf722cee26a3f88ab7f631c9ab9ba6ecdb49 Mon Sep 17 00:00:00 2001
From: Marcelo Tosatti <mtosatti@redhat.com>
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 <mtosatti@redhat.com>
Reported-by: Chuck Newman <chuck.newman@hpe.com>
Signed-off-by: John Kacur <jkacur@redhat.com>
---
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