chrt: make command syntax easier to understand in usage()

And mention in manual that the default is referring to the internal
default of this command, not the Linux system default.  Manual page
example also tries to be a little more complete how to use the command.

Signed-off-by: Sami Kerola <kerolasa@iki.fi>

diff --git a/schedutils/chrt.1 b/schedutils/chrt.1
index b85717bfae5b2746dd3a156cfc37232e066d1d3f..50aa8418a8162cd13876849122174b469ff79e89 100644 (file)
--- a/schedutils/chrt.1
+++ b/schedutils/chrt.1
@@ -91,8 +91,10 @@ Operate on an existing PID and do not launch a new task.
 .TP
 .B -r, --rr
 Set scheduling policy to
-.BR SCHED_RR
-(the default).
+.BR SCHED_RR .
+When policy is not defined the
+.B SCHED_RR
+is used as default.
 .TP
 .B -R, --reset-on-fork
 Add
@@ -123,7 +125,7 @@ You can also retrieve the real-time attributes of an existing task:
 .I pid
 .TP
 Or set them:
-.B chrt \-p
+.B chrt \-r \-p
 .I prio pid
 .SH PERMISSIONS
 A user must possess
@@ -138,6 +140,9 @@ and
 .BR SCHED_RR
 are part of POSIX 1003.1b Process Scheduling. The other scheduling attributes
 may be ignored on some systems.
+.P
+Linux default scheduling policy is
+.BR SCHED_OTHER .
 .SH AUTHOR
 Written by Robert M. Love.
 .SH COPYRIGHT

diff --git a/schedutils/chrt.c b/schedutils/chrt.c
index 60ec73e3af66f4ac25aa8a5931cc76870ba5f3f2..20df6fa6c4699c64c114aae2591dfe0463c2be06 100644 (file)
--- a/schedutils/chrt.c
+++ b/schedutils/chrt.c
@@ -62,9 +62,9 @@ static void __attribute__((__noreturn__)) show_usage(int rc)
        fprintf(out, _(
        "\nchrt - manipulate real-time attributes of a process\n"
        "\nSet policy:\n"
-       "  chrt [options] <policy> <priority> {<pid> | <command> [<arg> ...]}\n"
+       "  chrt [options] [-policy] <priority> [-p <pid> | <command> <arg> ...]\n"
        "\nGet policy:\n"
-       "  chrt [options] {<pid> | <command> [<arg> ...]}\n"));
+       "  chrt [options] -p <pid>\n"));
 
        fprintf(out, _(
        "\nScheduling policies:\n"