Merge branch 'master' of /pub/scm/linux/kernel/git/jejb/scsi-post-merge-2.6 into for-linus

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 @@
+#ifndef _LINUX_AVERAGE_H
+#define _LINUX_AVERAGE_H
+
+/* Exponentially weighted moving average (EWMA) */
+
+/* For more documentation see lib/average.c */
+
+struct ewma {
+        unsigned long internal;
+        unsigned long factor;
+        unsigned long weight;
+};
+
+extern void ewma_init(struct ewma *avg, unsigned long factor,
+                      unsigned long weight);
+
+extern struct ewma *ewma_add(struct ewma *avg, unsigned long val);
+
+/**
+ * ewma_read() - Get average value
+ * @avg: Average structure
+ *
+ * Returns the average value held in @avg.
+ */
+static inline unsigned long ewma_read(const struct ewma *avg)
+{
+        return avg->internal >> avg->factor;
+}
+
+#endif /* _LINUX_AVERAGE_H */