chrt: use correct min/max priorities

function                                             old     new   delta
chrt_main                                            369     432     +63
policies                                              48      96     +48
packed_usage                                       32239   32249     +10
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 3/0 up/down: 121/0)             Total: 121 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 14 insertions, 12 deletions

diff --git a/util-linux/chrt.c b/util-linux/chrt.c
index bbd6e2deb..27c8f43cc 100644
--- a/util-linux/chrt.c
+++ b/util-linux/chrt.c
@@ -35,6 +35,9 @@
 
 #include <sched.h>
 #include "libbb.h"
+#ifndef SCHED_IDLE
+# define SCHED_IDLE 5
+#endif
 
 static const struct {
         int policy;
@@ -79,18 +82,22 @@ int chrt_main(int argc UNUSED_PARAM, char **argv)
         const char *current_new;
         int policy = SCHED_RR;
 
-        /* only one policy accepted */
-        opt = getopt32(argv, "^+" "mprfobi" "\0" "r--fobi:f--robi:o--rfbi:b--rfoi:i--rfob");
+        opt = getopt32(argv, "^"
+                        "+" "mprfobi"
+                        "\0"
+                        /* only one policy accepted: */
+                        "r--fobi:f--robi:o--rfbi:b--rfoi:i--rfob"
+        );
         if (opt & OPT_m) { /* print min/max and exit */
+                show_min_max(SCHED_OTHER);
                 show_min_max(SCHED_FIFO);
                 show_min_max(SCHED_RR);
-                show_min_max(SCHED_OTHER);
                 show_min_max(SCHED_BATCH);
                 show_min_max(SCHED_IDLE);
                 fflush_stdout_and_exit(EXIT_SUCCESS);
         }
-        if (opt & OPT_r)
-                policy = SCHED_RR;
+        //if (opt & OPT_r)
+        //      policy = SCHED_RR; - default, already set
         if (opt & OPT_f)
                 policy = SCHED_FIFO;
         if (opt & OPT_o)
@@ -140,14 +147,9 @@ int chrt_main(int argc UNUSED_PARAM, char **argv)
                 current_new += 8;
         }
 
-        /* from the manpage of sched_getscheduler:
-        [...] sched_priority can have a value in the range 0 to 99.
-        [...] SCHED_OTHER, SCHED_BATCH or SCHED_IDLE must be assigned static
-                  priority 0.
-        [...] SCHED_FIFO or SCHED_RR can have static priority in 1..99 range.
-        */
         sp.sched_priority = xstrtou_range(priority, 0,
-                        (policy != SCHED_OTHER && policy != SCHED_BATCH && policy != SCHED_IDLE) ? 1 : 0, 99);
+                sched_get_priority_min(policy), sched_get_priority_max(policy)
+        );
 
         if (sched_setscheduler(pid, policy, &sp) < 0)
                 bb_perror_msg_and_die("can't %cet pid %d's policy", 's', (int)pid);