chrt: add support for SCHED_IDLE

Signed-off-by: Povilas Kanapickas <povilas@radix.lt>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 13 insertions, 8 deletions

diff --git a/util-linux/chrt.c b/util-linux/chrt.c
index e7abd4f5a..bbd6e2deb 100644
--- a/util-linux/chrt.c
+++ b/util-linux/chrt.c
@@ -17,7 +17,7 @@
 //kbuild:lib-$(CONFIG_CHRT) += chrt.o
 
 //usage:#define chrt_trivial_usage
-//usage:       "[-prfomb] [PRIO] [PID | PROG ARGS]"
+//usage:       "[-prfombi] [PRIO] [PID | PROG ARGS]"
 //usage:#define chrt_full_usage "\n\n"
 //usage:       "Change scheduling priority and class for a process\n"
 //usage:     "\n        -p      Operate on PID"
@@ -25,6 +25,7 @@
 //usage:     "\n        -f      Set SCHED_FIFO class"
 //usage:     "\n        -o      Set SCHED_OTHER class"
 //usage:     "\n        -b      Set SCHED_BATCH class"
+//usage:     "\n        -i      Set SCHED_IDLE class"
 //usage:     "\n        -m      Show min/max priorities"
 //usage:
 //usage:#define chrt_example_usage
@@ -42,12 +43,11 @@ static const struct {
         {SCHED_OTHER, "SCHED_OTHER"},
         {SCHED_FIFO, "SCHED_FIFO"},
         {SCHED_RR, "SCHED_RR"},
-        {SCHED_BATCH, "SCHED_BATCH"}
+        {SCHED_BATCH, "SCHED_BATCH"},
+        {0 /* unused */, ""},
+        {SCHED_IDLE, "SCHED_IDLE"}
 };
 
-//TODO: add
-// -i, SCHED_IDLE
-
 static void show_min_max(int pol)
 {
         const char *fmt = "%s min/max priority\t: %u/%u\n";
@@ -66,6 +66,7 @@ static void show_min_max(int pol)
 #define OPT_f (1<<3)
 #define OPT_o (1<<4)
 #define OPT_b (1<<5)
+#define OPT_i (1<<6)
 
 int chrt_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int chrt_main(int argc UNUSED_PARAM, char **argv)
@@ -79,12 +80,13 @@ int chrt_main(int argc UNUSED_PARAM, char **argv)
         int policy = SCHED_RR;
 
         /* only one policy accepted */
-        opt = getopt32(argv, "^+" "mprfob" "\0" "r--fob:f--rob:o--rfb:b--rfo");
+        opt = getopt32(argv, "^+" "mprfobi" "\0" "r--fobi:f--robi:o--rfbi:b--rfoi:i--rfob");
         if (opt & OPT_m) { /* print min/max and exit */
                 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)
@@ -95,6 +97,8 @@ int chrt_main(int argc UNUSED_PARAM, char **argv)
                 policy = SCHED_OTHER;
         if (opt & OPT_b)
                 policy = SCHED_BATCH;
+        if (opt & OPT_i)
+                policy = SCHED_IDLE;
 
         argv += optind;
         if (!argv[0])
@@ -138,11 +142,12 @@ int chrt_main(int argc UNUSED_PARAM, char **argv)
 
         /* from the manpage of sched_getscheduler:
         [...] sched_priority can have a value in the range 0 to 99.
-        [...] SCHED_OTHER or SCHED_BATCH must be assigned static priority 0.
+        [...] 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) ? 1 : 0, 99);
+                        (policy != SCHED_OTHER && policy != SCHED_BATCH && policy != SCHED_IDLE) ? 1 : 0, 99);
 
         if (sched_setscheduler(pid, policy, &sp) < 0)
                 bb_perror_msg_and_die("can't %cet pid %d's policy", 's', (int)pid);