From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262255AbVDLOQW (ORCPT ); Tue, 12 Apr 2005 10:16:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262254AbVDLLIg (ORCPT ); Tue, 12 Apr 2005 07:08:36 -0400 Received: from fire.osdl.org ([65.172.181.4]:27594 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S262253AbVDLKdO (ORCPT ); Tue, 12 Apr 2005 06:33:14 -0400 Message-Id: <200504121033.j3CAX5cJ005773@shell0.pdx.osdl.net> Subject: [patch 154/198] IPoIB: fix static rate calculation To: torvalds@osdl.org Cc: linux-kernel@vger.kernel.org, akpm@osdl.org, roland@topspin.com From: akpm@osdl.org Date: Tue, 12 Apr 2005 03:32:59 -0700 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org From: Roland Dreier 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 Signed-off-by: Andrew Morton --- 25-akpm/drivers/infiniband/ulp/ipoib/ipoib_main.c | 7 +++---- 25-akpm/drivers/infiniband/ulp/ipoib/ipoib_multicast.c | 7 +++---- 2 files changed, 6 insertions(+), 8 deletions(-) diff -puN drivers/infiniband/ulp/ipoib/ipoib_main.c~ipoib-fix-static-rate-calculation drivers/infiniband/ulp/ipoib/ipoib_main.c --- 25/drivers/infiniband/ulp/ipoib/ipoib_main.c~ipoib-fix-static-rate-calculation 2005-04-12 03:21:40.451987264 -0700 +++ 25-akpm/drivers/infiniband/ulp/ipoib/ipoib_main.c 2005-04-12 03:21:40.456986504 -0700 @@ -302,11 +302,10 @@ static void path_rec_completion(int stat .sl = pathrec->sl, .port_num = priv->port }; + int path_rate = ib_sa_rate_enum_to_int(pathrec->rate); - if (ib_sa_rate_enum_to_int(pathrec->rate) > 0) - av.static_rate = (2 * priv->local_rate - - ib_sa_rate_enum_to_int(pathrec->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(priv, "static_rate %d for local port %dX, path %dX\n", av.static_rate, priv->local_rate, diff -puN drivers/infiniband/ulp/ipoib/ipoib_multicast.c~ipoib-fix-static-rate-calculation drivers/infiniband/ulp/ipoib/ipoib_multicast.c --- 25/drivers/infiniband/ulp/ipoib/ipoib_multicast.c~ipoib-fix-static-rate-calculation 2005-04-12 03:21:40.453986960 -0700 +++ 25-akpm/drivers/infiniband/ulp/ipoib/ipoib_multicast.c 2005-04-12 03:21:40.457986352 -0700 @@ -258,13 +258,12 @@ static int ipoib_mcast_join_finish(struc .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, _