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>

realtime-tests.spec

@@ -6,7 +6,7 @@ Name: realtime-tests
 # Numa argument to make:  NUMA=1
 #
 Version: 2.6
-Release: 3%{?dist}
+Release: 4%{?dist}
 License: GPLv2
 URL: https://git.kernel.org/pub/scm/utils/rt-tests/rt-tests.git
 Source0: https://www.kernel.org/pub/linux/utils/rt-tests/rt-tests-%{version}.tar.xz
@@ -30,6 +30,8 @@ Patch7: rt-tests-cyclicdeadline-Add-histogram-support.patch
 Patch8: rt-tests-cyclics-Fix-json-segfault-when-not-using-hi.patch
 Patch9: rt-tests-cyclicdeadline-Print-the-histogram-regardle.patch
 Patch10: rt-tests-cyclicdeadline-Remove-dead-verbose-code-in-.patch
+Patch11: rt-tests-oslat-should-use-MHz-not-Mhz.patch
+Patch12: rt-tests-oslat-convert-to-nanoseconds-correctly.patch
 
 %description
 realtime-tests is a set of programs that test and measure various components of
@@ -98,6 +100,11 @@ latency. It also tests the functioning of priority-inheritance mutexes.
 %{_mandir}/man8/determine_maximum_mpps.8.*
 
 %changelog
+* Mon Feb 05 2024 John Kacur <jkacur@redhat.com> - 2.6-4
+- oslat: correct spelling of Mhz to MHz
+- oslat: Fix conversion to nanoseconds for 1us bucket
+Resolves: RHEL-23909
+
 * Fri Jan 26 2024 Crystal Wood <crwood@redhat.com> - 2.6-3
 - Fix issues with with using --json without --histogram (both cyclictest and
   cyclicdeadline), and using --histogram without --quiet in cyclicdeadline.

rt-tests-oslat-convert-to-nanoseconds-correctly.patch

@@ -0,0 +1,42 @@
+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
+

rt-tests-oslat-should-use-MHz-not-Mhz.patch

@@ -0,0 +1,34 @@
+From 251d082403b371098c8420c01d1b058b12a9cc78 Mon Sep 17 00:00:00 2001
+From: Marcelo Tosatti <mtosatti@redhat.com>
+Date: Thu, 1 Feb 2024 13:05:38 -0300
+Subject: [PATCH 1/2] rt-tests: oslat should use MHz, not Mhz
+
+Usage of Mhz, in oslat, is incorrect:
+
+From https://www.nist.gov/pml/owm/writing-si-metric-system-units#:~:text=NOT%20250%20mms.-,Capitalization,the%20beginning%20of%20the%20sentence:
+
+"When the unit is derived from the name of a person, the symbol or the first letter of the symbol is an uppercase letter (W for the unit "watt" or Pa for the unit "pascal")."
+
+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 4bdca643da72..e398f205b40a 100644
+--- a/src/oslat/oslat.c
++++ b/src/oslat/oslat.c
+@@ -501,7 +501,7 @@ static void write_summary(struct thread *t)
+ 	calculate(t);
+ 
+ 	putfield("Core", t[i].core_i, "d", "");
+-	putfield("Counter Freq", t[i].counter_mhz, "u", " (Mhz)");
++	putfield("Counter Freq", t[i].counter_mhz, "u", " (MHz)");
+ 
+ 	for (j = 0; j < g.bucket_size; j++) {
+ 		if (j < g.bucket_size-1 && g.output_omit_zero_buckets) {
+-- 
+2.43.0
+