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-rw-r--r--include/linux/sched/prio.h45
1 files changed, 45 insertions, 0 deletions
diff --git a/include/linux/sched/prio.h b/include/linux/sched/prio.h
new file mode 100644
index 000000000..ab83d85e1
--- /dev/null
+++ b/include/linux/sched/prio.h
@@ -0,0 +1,45 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_SCHED_PRIO_H
+#define _LINUX_SCHED_PRIO_H
+
+#define MAX_NICE 19
+#define MIN_NICE -20
+#define NICE_WIDTH (MAX_NICE - MIN_NICE + 1)
+
+/*
+ * Priority of a process goes from 0..MAX_PRIO-1, valid RT
+ * priority is 0..MAX_RT_PRIO-1, and SCHED_NORMAL/SCHED_BATCH
+ * tasks are in the range MAX_RT_PRIO..MAX_PRIO-1. Priority
+ * values are inverted: lower p->prio value means higher priority.
+ */
+
+#define MAX_RT_PRIO 100
+
+#define MAX_PRIO (MAX_RT_PRIO + NICE_WIDTH)
+#define DEFAULT_PRIO (MAX_RT_PRIO + NICE_WIDTH / 2)
+
+/*
+ * Convert user-nice values [ -20 ... 0 ... 19 ]
+ * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ],
+ * and back.
+ */
+#define NICE_TO_PRIO(nice) ((nice) + DEFAULT_PRIO)
+#define PRIO_TO_NICE(prio) ((prio) - DEFAULT_PRIO)
+
+/*
+ * Convert nice value [19,-20] to rlimit style value [1,40].
+ */
+static inline long nice_to_rlimit(long nice)
+{
+ return (MAX_NICE - nice + 1);
+}
+
+/*
+ * Convert rlimit style value [1,40] to nice value [-20, 19].
+ */
+static inline long rlimit_to_nice(long prio)
+{
+ return (MAX_NICE - prio + 1);
+}
+
+#endif /* _LINUX_SCHED_PRIO_H */