From patchwork Fri Jul 17 23:13:30 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andy Grover X-Patchwork-Id: 29946 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@bilbo.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from ozlabs.org (ozlabs.org [203.10.76.45]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "mx.ozlabs.org", Issuer "CA Cert Signing Authority" (verified OK)) by bilbo.ozlabs.org (Postfix) with ESMTPS id 3F188B6F44 for ; Sat, 18 Jul 2009 09:45:20 +1000 (EST) Received: by ozlabs.org (Postfix) id 33839DDDA0; Sat, 18 Jul 2009 09:45:20 +1000 (EST) Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by ozlabs.org (Postfix) with ESMTP id B413ADDD04 for ; Sat, 18 Jul 2009 09:45:19 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758073AbZGQXpD (ORCPT ); Fri, 17 Jul 2009 19:45:03 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758046AbZGQXpB (ORCPT ); Fri, 17 Jul 2009 19:45:01 -0400 Received: from rcsinet12.oracle.com ([148.87.113.124]:30173 "EHLO rgminet12.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758061AbZGQXox (ORCPT ); Fri, 17 Jul 2009 19:44:53 -0400 Received: from rgminet15.oracle.com (rcsinet15.oracle.com [148.87.113.117]) by rgminet12.oracle.com (Switch-3.3.1/Switch-3.3.1) with ESMTP id n6HNiRK2030308 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Fri, 17 Jul 2009 23:44:28 GMT Received: from abhmt004.oracle.com (abhmt004.oracle.com [141.146.116.13]) by rgminet15.oracle.com (Switch-3.3.1/Switch-3.3.1) with ESMTP id n6HNin0K014401; Fri, 17 Jul 2009 23:44:49 GMT Received: from localhost.localdomain (/139.185.48.5) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Fri, 17 Jul 2009 16:14:00 -0700 From: Andy Grover To: netdev@vger.kernel.org Cc: rds-devel@oss.oracle.com Subject: [PATCH 09/15] RDS/IB: Disable flow control in sysctl and explain why Date: Fri, 17 Jul 2009 16:13:30 -0700 Message-Id: <1247872416-17834-10-git-send-email-andy.grover@oracle.com> X-Mailer: git-send-email 1.6.0.4 In-Reply-To: <1247872416-17834-1-git-send-email-andy.grover@oracle.com> References: <1247872416-17834-1-git-send-email-andy.grover@oracle.com> X-Source-IP: abhmt004.oracle.com [141.146.116.13] X-Auth-Type: Internal IP X-CT-RefId: str=0001.0A010206.4A610CF1.00AD:SCFSTAT5015188,ss=1,fgs=0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Backwards compatibility with rds 3.0 causes protocol- based flow control to be disabled as a side-effect. I don't want to pull out FC support from the IB transport but I do want to document and keep the sysctl consistent if possible. Signed-off-by: Andy Grover --- net/rds/ib_sysctl.c | 12 +++++++++++- 1 files changed, 11 insertions(+), 1 deletions(-) diff --git a/net/rds/ib_sysctl.c b/net/rds/ib_sysctl.c index d87830d..84b5ffc 100644 --- a/net/rds/ib_sysctl.c +++ b/net/rds/ib_sysctl.c @@ -53,7 +53,17 @@ unsigned long rds_ib_sysctl_max_unsig_bytes = (16 << 20); static unsigned long rds_ib_sysctl_max_unsig_bytes_min = 1; static unsigned long rds_ib_sysctl_max_unsig_bytes_max = ~0UL; -unsigned int rds_ib_sysctl_flow_control = 1; +/* + * This sysctl does nothing. + * + * Backwards compatibility with RDS 3.0 wire protocol + * disables initial FC credit exchange. + * If it's ever possible to drop 3.0 support, + * setting this to 1 and moving init/refill of send/recv + * rings from ib_cm_connect_complete() back into ib_setup_qp() + * will cause credits to be added before protocol negotiation. + */ +unsigned int rds_ib_sysctl_flow_control = 0; ctl_table rds_ib_sysctl_table[] = { {