diff options
| author | Roland Dreier <roland@topspin.com> | 2005-04-16 15:26:06 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:26:06 -0700 |
| commit | e6ded99cbbbfef2cef537d717ad61d2f77f4dfd6 (patch) | |
| tree | 44ef73e8f9ac7bdfc71ff3286e6b2715aafbbd9d /drivers/infiniband/ulp/ipoib/ipoib_multicast.c | |
| parent | 62241eb497721be7640e5d9330e60f4a88a4db46 (diff) | |
| download | lwn-e6ded99cbbbfef2cef537d717ad61d2f77f4dfd6.tar.gz lwn-e6ded99cbbbfef2cef537d717ad61d2f77f4dfd6.zip | |
[PATCH] IPoIB: fix static rate calculation
Correct and simplify calculation of static rate. We need to round up the
quotient of (local_rate - path_rate) / path_rate. To round up we add
(path_rate - 1) to the numerator, so the quotient simplifies to (local_rate -
1) / path_rate.
No idea how I came up with the old formula.
Signed-off-by: Roland Dreier <roland@topspin.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'drivers/infiniband/ulp/ipoib/ipoib_multicast.c')
| -rw-r--r-- | drivers/infiniband/ulp/ipoib/ipoib_multicast.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c index f46932dc81c9..70208c3d21e2 100644 --- a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c +++ b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c @@ -258,13 +258,12 @@ static int ipoib_mcast_join_finish(struct ipoib_mcast *mcast, .traffic_class = mcast->mcmember.traffic_class } }; + int path_rate = ib_sa_rate_enum_to_int(mcast->mcmember.rate); av.grh.dgid = mcast->mcmember.mgid; - if (ib_sa_rate_enum_to_int(mcast->mcmember.rate) > 0) - av.static_rate = (2 * priv->local_rate - - ib_sa_rate_enum_to_int(mcast->mcmember.rate) - 1) / - (priv->local_rate ? priv->local_rate : 1); + if (path_rate > 0 && priv->local_rate > path_rate) + av.static_rate = (priv->local_rate - 1) / path_rate; ipoib_dbg_mcast(priv, "static_rate %d for local port %dX, mcmember %dX\n", av.static_rate, priv->local_rate, |