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authorAndrea Bastoni <bastoni@cs.unc.edu>2011-08-27 09:43:54 -0400
committerAndrea Bastoni <bastoni@cs.unc.edu>2011-08-27 10:06:11 -0400
commit7b1bb388bc879ffcc6c69b567816d5c354afe42b (patch)
tree5a217fdfb0b5e5a327bdcd624506337c1ae1fe32 /include/linux/average.h
parent7d754596756240fa918b94cd0c3011c77a638987 (diff)
parent02f8c6aee8df3cdc935e9bdd4f2d020306035dbe (diff)
Merge 'Linux v3.0' into Litmus
Some notes: * Litmus^RT scheduling class is the topmost scheduling class (above stop_sched_class). * scheduler_ipi() function (e.g., in smp_reschedule_interrupt()) may increase IPI latencies. * Added path into schedule() to quickly re-evaluate scheduling decision without becoming preemptive again. This used to be a standard path before the removal of BKL. Conflicts: Makefile arch/arm/kernel/calls.S arch/arm/kernel/smp.c arch/x86/include/asm/unistd_32.h arch/x86/kernel/smp.c arch/x86/kernel/syscall_table_32.S include/linux/hrtimer.h kernel/printk.c kernel/sched.c kernel/sched_fair.c
Diffstat (limited to 'include/linux/average.h')
-rw-r--r--include/linux/average.h30
1 files changed, 30 insertions, 0 deletions
diff --git a/include/linux/average.h b/include/linux/average.h
new file mode 100644
index 000000000000..c6028fd742c1
--- /dev/null
+++ b/include/linux/average.h
@@ -0,0 +1,30 @@
1#ifndef _LINUX_AVERAGE_H
2#define _LINUX_AVERAGE_H
3
4/* Exponentially weighted moving average (EWMA) */
5
6/* For more documentation see lib/average.c */
7
8struct ewma {
9 unsigned long internal;
10 unsigned long factor;
11 unsigned long weight;
12};
13
14extern void ewma_init(struct ewma *avg, unsigned long factor,
15 unsigned long weight);
16
17extern struct ewma *ewma_add(struct ewma *avg, unsigned long val);
18
19/**
20 * ewma_read() - Get average value
21 * @avg: Average structure
22 *
23 * Returns the average value held in @avg.
24 */
25static inline unsigned long ewma_read(const struct ewma *avg)
26{
27 return avg->internal >> avg->factor;
28}
29
30#endif /* _LINUX_AVERAGE_H */