summaryrefslogtreecommitdiff
path: root/include/linux/sched/loadavg.h
diff options
context:
space:
mode:
Diffstat (limited to 'include/linux/sched/loadavg.h')
-rw-r--r--include/linux/sched/loadavg.h31
1 files changed, 31 insertions, 0 deletions
diff --git a/include/linux/sched/loadavg.h b/include/linux/sched/loadavg.h
new file mode 100644
index 000000000000..4264bc6b2c27
--- /dev/null
+++ b/include/linux/sched/loadavg.h
@@ -0,0 +1,31 @@
+#ifndef _LINUX_SCHED_LOADAVG_H
+#define _LINUX_SCHED_LOADAVG_H
+
+/*
+ * These are the constant used to fake the fixed-point load-average
+ * counting. Some notes:
+ * - 11 bit fractions expand to 22 bits by the multiplies: this gives
+ * a load-average precision of 10 bits integer + 11 bits fractional
+ * - if you want to count load-averages more often, you need more
+ * precision, or rounding will get you. With 2-second counting freq,
+ * the EXP_n values would be 1981, 2034 and 2043 if still using only
+ * 11 bit fractions.
+ */
+extern unsigned long avenrun[]; /* Load averages */
+extern void get_avenrun(unsigned long *loads, unsigned long offset, int shift);
+
+#define FSHIFT 11 /* nr of bits of precision */
+#define FIXED_1 (1<<FSHIFT) /* 1.0 as fixed-point */
+#define LOAD_FREQ (5*HZ+1) /* 5 sec intervals */
+#define EXP_1 1884 /* 1/exp(5sec/1min) as fixed-point */
+#define EXP_5 2014 /* 1/exp(5sec/5min) */
+#define EXP_15 2037 /* 1/exp(5sec/15min) */
+
+#define CALC_LOAD(load,exp,n) \
+ load *= exp; \
+ load += n*(FIXED_1-exp); \
+ load >>= FSHIFT;
+
+extern void calc_global_load(unsigned long ticks);
+
+#endif /* _LINUX_SCHED_LOADAVG_H */