Unfortunately this commit introduces a bug because the priority is not
retested, and this can result in reported priorities below 0.
For example,
sudo ./cyclictest -t3 -p1
policy: fifo: loadavg: 0.09 0.06 0.05 1/331 21732
T: 0 (21730) P: 1 I:1000 C: 593 Min: 34 Act: 155 Avg: 100 Max: 672
T: 1 (21731) P: 0 I:1500 C: 395 Min: 15 Act: 43 Avg: 72 Max: 853
T: 2 (21732) P:-1 I:2000 C: 297 Min: 21 Act: 57 Avg: 79 Max: 330
Notice that the last priority is reported as -1.
After reverting this commit, we get the correct expected behaviour.
sudo ./cyclictest -t3 -p1
policy: fifo: loadavg: 0.07 0.05 0.04 2/330 21754
T: 0 (21752) P: 1 I:1000 C: 11600 Min: 13 Act: 7072 Avg: 3593 Max: 7841
T: 1 (21753) P: 0 I:1500 C: 7737 Min: 12 Act: 1572 Avg: 516 Max: 2381
T: 2 (21754) P: 0 I:2000 C: 5804 Min: 12 Act: 53 Avg: 59 Max: 548
I think it can be argued that the original code is also clearer, although
that is somewhat subjective. With the original code I don't need to track
down exactly what "sameprio" means, and it is clear what is being tested.
Signed-off-by: John Kacur <jkacur@xxxxxxxxxx>
---
src/cyclictest/cyclictest.c | 7 ++-----
1 files changed, 2 insertions(+), 5 deletions(-)
diff --git a/src/cyclictest/cyclictest.c b/src/cyclictest/cyclictest.c
index dc86b49..d38c0a7 100644
--- a/src/cyclictest/cyclictest.c
+++ b/src/cyclictest/cyclictest.c
@@ -801,7 +801,6 @@ static int interval = 1000;
static int distance = 500;
static int affinity = 0;
static int smp = 0;
-static int sameprio = 0;
enum {
AFFINITY_UNSPECIFIED,
@@ -1043,9 +1042,7 @@ static void process_options (int argc, char *argv[])
if (num_threads < 1)
error = 1;
- if (priority && (smp || numa || histogram))
- sameprio = 1;
-
+
if (error)
display_help(1);
}
@@ -1304,7 +1301,7 @@ int main(int argc, char **argv)
}
par->prio = priority;
- if (!sameprio)
+ if (priority && !histogram && !smp && !numa)
priority--;
if (priority && policy <= 1) par->policy = SCHED_FIFO;
else if (priority && policy == 2) par->policy = SCHED_RR;
--
1.6.0.6
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