average: change to declare precision, not factor
Declaring the factor is counter-intuitive, and people are prone
to using small(-ish) values even when that makes no sense.
Change the DECLARE_EWMA() macro to take the fractional precision,
in bits, rather than a factor, and update all users.
While at it, add some more documentation.
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index bf95016..e9d7e2b 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -51,7 +51,7 @@ module_param(gso, bool, 0444);
* at once, the weight is chosen so that the EWMA will be insensitive to short-
* term, transient changes in packet size.
*/
-DECLARE_EWMA(pkt_len, 1, 64)
+DECLARE_EWMA(pkt_len, 0, 64)
/* With mergeable buffers we align buffer address and use the low bits to
* encode its true size. Buffer size is up to 1 page so we need to align to