[PATCH v2] chrt: Allow optional priority for non‑prio policies without --pid

[PATCH v2] chrt: Allow optional priority for non‑prio policies without --pid

[Madadi Vineeth Reddy]

This extends commit e7a2d62434c2
("chrt: Make priority optional for policies that don't use it")
so that priority arguments are optional even when --pid is not specified.

Before this patch:
$ chrt --other ls -lh
chrt: invalid priority argument: 'ls'
-> only "chrt --other 0 ls -lh" would work

After this patch:
$ chrt --other ls -lh
$ chrt --other 0 ls -lh
-> both now work

If an out‑of‑range priority is given, it reports an error:
$ chrt --other 1 ls -lh
unsupported priority value for the policy: 1 (see --max for valid range)

Changes in v2:
- Removed is_number() and used isdigit_string() (Karel Zak)
- used _() for translation (Karel Zak)

Fixes: e7a2d62434c2 ("chrt: Make priority optional for policies that don't use it")
Signed-off-by: Madadi Vineeth Reddy <vineethr@linux.ibm.com>
---
 schedutils/chrt.c | 21 +++++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

diff --git a/schedutils/chrt.c b/schedutils/chrt.c
index 10ba7fbf6..1a9522728 100644
--- a/schedutils/chrt.c
+++ b/schedutils/chrt.c
@@ -503,7 +503,7 @@ int main(int argc, char **argv)
 		}
 	}
 
-	if (argc - optind < (ctl->pid == 0 ? 1 : 2)) {
+	if (argc - optind < 1) {
 		warnx(_("too few arguments"));
 		errtryhelp(EXIT_FAILURE);
 	}
@@ -527,7 +527,10 @@ int main(int argc, char **argv)
 	if (ctl->verbose)
 		show_sched_info(ctl);
 
-	if (argc - optind > 1) {
+	bool have_prio = need_prio ||
+		(ctl->pid == -1 ? (optind < argc && isdigit_string(argv[optind])) : (argc - optind > 1));
+
+	if (have_prio) {
 		errno = 0;
 		ctl->priority = strtos32_or_err(argv[optind], _("invalid priority argument"));
 	} else
@@ -568,9 +571,19 @@ int main(int argc, char **argv)
 		show_sched_info(ctl);
 
 	if (!ctl->pid) {
-		argv += optind + 1;
-		if (strcmp(argv[0], "--") == 0)
+		argv += optind;
+
+		if (need_prio)
 			argv++;
+		else if (argv[0] && isdigit_string(argv[0]))
+			argv++;
+
+		if (argv[0] && strcmp(argv[0], "--") == 0)
+			argv++;
+
+		if (!argv[0])
+			errx(EXIT_FAILURE, _("no command specified"));
+
 		execvp(argv[0], argv);
 		errexec(argv[0]);
 	}
-- 
2.49.0

Re: [PATCH v2] chrt: Allow optional priority for non‑prio policies without --pid

[Karel Zak]

On Tue, Jul 29, 2025 at 03:17:03PM +0530, Madadi Vineeth Reddy wrote:
>  schedutils/chrt.c | 21 +++++++++++++++++----
>  1 file changed, 17 insertions(+), 4 deletions(-)

Applied, thanks.

-- 
 Karel Zak  <kzak@redhat.com>
 http://karelzak.blogspot.com