Previously, running "chrt --pid <pid>" with no policy options
would display the process’s current scheduling attributes, but
specifying a policy without a priority (e.g. chrt --rr --pid <pid>)
would silently fallback to displaying the same info. This was
confusing, since a policy option normally implies an intent to
change something.
This patch changes the behavior so that
chrt --pid <pid> continues to show the current settings:
chrt --pid 10862
pid 10862's current scheduling policy: SCHED_OTHER
pid 10862's current scheduling priority: 0
pid 10862's current runtime parameter: 2800000
If a policy is specified but no priority follows, chrt now
errors out:
chrt --rr --pid 10862
chrt: policy SCHED_RR requires a priority argument
Verbose output (-v) still prints the current settings when a
valid policy+priority is provided.
Signed-off-by: Madadi Vineeth Reddy <vineethr@xxxxxxxxxxxxx>
---
schedutils/chrt.c | 25 +++++++++++++++++++++----
1 file changed, 21 insertions(+), 4 deletions(-)
diff --git a/schedutils/chrt.c b/schedutils/chrt.c
index 8fe748f43..d694845ac 100644
--- a/schedutils/chrt.c
+++ b/schedutils/chrt.c
@@ -64,7 +64,7 @@ static void __attribute__((__noreturn__)) usage(void)
" chrt [options] --pid <priority> <pid>\n"), out);
fputs(USAGE_SEPARATOR, out);
fputs(_("Get policy:\n"
- " chrt [options] --pid <pid>\n"), out);
+ " chrt --pid <pid>\n"), out);
fputs(USAGE_SEPARATOR, out);
fputs(_("Policy options:\n"), out);
@@ -399,6 +399,7 @@ int main(int argc, char **argv)
{
struct chrt_ctl _ctl = { .pid = -1, .policy = SCHED_RR }, *ctl = &_ctl;
int c;
+ bool policy_given = false;
static const struct option longopts[] = {
{ "all-tasks", no_argument, NULL, 'a' },
@@ -435,21 +436,25 @@ int main(int argc, char **argv)
case 'b':
#ifdef SCHED_BATCH
ctl->policy = SCHED_BATCH;
+ policy_given = true;
#endif
break;
case 'd':
#ifdef SCHED_DEADLINE
ctl->policy = SCHED_DEADLINE;
+ policy_given = true;
#endif
break;
case 'e':
#ifdef SCHED_EXT
ctl->policy = SCHED_EXT;
+ policy_given = true;
#endif
break;
case 'f':
ctl->policy = SCHED_FIFO;
+ policy_given = true;
break;
case 'R':
ctl->reset_on_fork = 1;
@@ -457,6 +462,7 @@ int main(int argc, char **argv)
case 'i':
#ifdef SCHED_IDLE
ctl->policy = SCHED_IDLE;
+ policy_given = true;
#endif
break;
case 'm':
@@ -464,6 +470,7 @@ int main(int argc, char **argv)
return EXIT_SUCCESS;
case 'o':
ctl->policy = SCHED_OTHER;
+ policy_given = true;
break;
case 'p':
errno = 0;
@@ -472,6 +479,7 @@ int main(int argc, char **argv)
break;
case 'r':
ctl->policy = SCHED_RR;
+ policy_given = true;
break;
case 'v':
ctl->verbose = 1;
@@ -501,12 +509,21 @@ int main(int argc, char **argv)
errtryhelp(EXIT_FAILURE);
}
- if ((ctl->pid > -1) && (ctl->verbose || argc - optind == 1)) {
+ /* pid exists but priority not given */
+ if (ctl->pid > -1 && argc - optind == 1) {
+ /* Error if a policy was specified but no priority given */
+ if (policy_given)
+ errx(EXIT_FAILURE, ("policy %s requires a priority argument"),
+ get_policy_name(ctl->policy));
+
+ /* If no policy specified, show current settings */
show_sched_info(ctl);
- if (argc - optind == 1)
- return EXIT_SUCCESS;
+ return EXIT_SUCCESS;
}
+ if (ctl->verbose)
+ show_sched_info(ctl);
+
errno = 0;
ctl->priority = strtos32_or_err(argv[optind], _("invalid priority argument"));
--
2.49.0
