From patchwork Sat Nov 15 12:11:18 2008 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gerrit Renker X-Patchwork-Id: 8906 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org 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 087C6DDE3A for ; Sat, 15 Nov 2008 23:11:50 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755478AbYKOMLp (ORCPT ); Sat, 15 Nov 2008 07:11:45 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755285AbYKOMLp (ORCPT ); Sat, 15 Nov 2008 07:11:45 -0500 Received: from dee.erg.abdn.ac.uk ([139.133.204.82]:42066 "EHLO erg.abdn.ac.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755416AbYKOMLm (ORCPT ); Sat, 15 Nov 2008 07:11:42 -0500 Received: from laptev.erg.abdn.ac.uk (Debian-exim@ra-gerrit.erg.abdn.ac.uk [139.133.204.38]) by erg.abdn.ac.uk (8.13.4/8.13.4) with ESMTP id mAFCBJAv023080 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=NOT); Sat, 15 Nov 2008 12:11:19 GMT Received: from root by laptev.erg.abdn.ac.uk with local (Exim 4.69) (envelope-from ) id 1L1Jzj-0003v0-La; Sat, 15 Nov 2008 13:11:19 +0100 From: Gerrit Renker To: davem@davemloft.net Cc: dccp@vger.kernel.org, netdev@vger.kernel.org, Gerrit Renker Subject: [PATCH 4/5] dccp: Deprecate Ack Ratio sysctl Date: Sat, 15 Nov 2008 13:11:18 +0100 Message-Id: <1226751079-15019-5-git-send-email-gerrit@erg.abdn.ac.uk> X-Mailer: git-send-email 1.6.0.rc2 In-Reply-To: <1226751079-15019-4-git-send-email-gerrit@erg.abdn.ac.uk> References: <20081112063643.GB6405@gerrit.erg.abdn.ac.uk> <1226751079-15019-1-git-send-email-gerrit@erg.abdn.ac.uk> <1226751079-15019-2-git-send-email-gerrit@erg.abdn.ac.uk> <1226751079-15019-3-git-send-email-gerrit@erg.abdn.ac.uk> <1226751079-15019-4-git-send-email-gerrit@erg.abdn.ac.uk> X-ERG-MailScanner: Found to be clean X-ERG-MailScanner-From: root@erg.abdn.ac.uk X-Spam-Status: No Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org This patch deprecates the Ack Ratio sysctl, since * Ack Ratio is entirely ignored by CCID-3 and CCID-4, * Ack Ratio currently doesn't work in CCID-2 (i.e. is always set to 1); * even if it would work in CCID-2, there is no point for a user to change it: - Ack Ratio is constrained by cwnd (RFC 4341, 6.1.2), - if Ack Ratio > cwnd, the system resorts to spurious RTO timeouts (since waiting for Acks which will never arrive in this window), - cwnd is not a user-configurable value. The only reasonable place for Ack Ratio is to print it for debugging. It is planned to do this later on, as part of e.g. dccp_probe. With this patch Ack Ratio is now under full control of feature negotiation: * Ack Ratio is resolved as a dependency of the selected CCID; * if the chosen CCID supports it (i.e. CCID == CCID-2), Ack Ratio is set to the default of 2, following RFC 4340, 11.3 - "New connections start with Ack Ratio 2 for both endpoints"; * what happens then is part of another patch set, since it concerns the dynamic update of Ack Ratio while the connection is in full flight. Thanks to Tomasz Grobelny for discussion leading up to this patch. Signed-off-by: Gerrit Renker Acked-by: Arnaldo Carvalho de Melo --- Documentation/networking/dccp.txt | 3 --- include/linux/dccp.h | 2 -- net/dccp/dccp.h | 1 - net/dccp/minisocks.c | 1 - net/dccp/options.c | 1 - net/dccp/sysctl.c | 7 ------- 6 files changed, 0 insertions(+), 15 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html --- a/Documentation/networking/dccp.txt +++ b/Documentation/networking/dccp.txt @@ -125,9 +125,6 @@ send_ndp = 1 send_ackvec = 1 Whether or not to send Ack Vector options (sec. 11.5). -ack_ratio = 2 - The default Ack Ratio (sec. 11.3) to use. - tx_ccid = 2 Default CCID for the sender-receiver half-connection. --- a/include/linux/dccp.h +++ b/include/linux/dccp.h @@ -368,7 +368,6 @@ static inline unsigned int dccp_hdr_len(const struct sk_buff *skb) * @dccpms_ccid - Congestion Control Id (CCID) (section 10) * @dccpms_send_ack_vector - Send Ack Vector Feature (section 11.5) * @dccpms_send_ndp_count - Send NDP Count Feature (7.7.2) - * @dccpms_ack_ratio - Ack Ratio Feature (section 11.3) * @dccpms_pending - List of features being negotiated * @dccpms_conf - */ @@ -378,7 +377,6 @@ struct dccp_minisock { __u8 dccpms_tx_ccid; __u8 dccpms_send_ack_vector; __u8 dccpms_send_ndp_count; - __u8 dccpms_ack_ratio; struct list_head dccpms_pending; struct list_head dccpms_conf; }; --- a/net/dccp/dccp.h +++ b/net/dccp/dccp.h @@ -98,7 +98,6 @@ extern int sysctl_dccp_retries2; extern int sysctl_dccp_feat_sequence_window; extern int sysctl_dccp_feat_rx_ccid; extern int sysctl_dccp_feat_tx_ccid; -extern int sysctl_dccp_feat_ack_ratio; extern int sysctl_dccp_feat_send_ack_vector; extern int sysctl_dccp_feat_send_ndp_count; extern int sysctl_dccp_tx_qlen; --- a/net/dccp/minisocks.c +++ b/net/dccp/minisocks.c @@ -47,7 +47,6 @@ void dccp_minisock_init(struct dccp_minisock *dmsk) dmsk->dccpms_sequence_window = sysctl_dccp_feat_sequence_window; dmsk->dccpms_rx_ccid = sysctl_dccp_feat_rx_ccid; dmsk->dccpms_tx_ccid = sysctl_dccp_feat_tx_ccid; - dmsk->dccpms_ack_ratio = sysctl_dccp_feat_ack_ratio; dmsk->dccpms_send_ack_vector = sysctl_dccp_feat_send_ack_vector; dmsk->dccpms_send_ndp_count = sysctl_dccp_feat_send_ndp_count; } --- a/net/dccp/options.c +++ b/net/dccp/options.c @@ -26,7 +26,6 @@ int sysctl_dccp_feat_sequence_window = DCCPF_INITIAL_SEQUENCE_WINDOW; int sysctl_dccp_feat_rx_ccid = DCCPF_INITIAL_CCID; int sysctl_dccp_feat_tx_ccid = DCCPF_INITIAL_CCID; -int sysctl_dccp_feat_ack_ratio = DCCPF_INITIAL_ACK_RATIO; int sysctl_dccp_feat_send_ack_vector = DCCPF_INITIAL_SEND_ACK_VECTOR; int sysctl_dccp_feat_send_ndp_count = DCCPF_INITIAL_SEND_NDP_COUNT; --- a/net/dccp/sysctl.c +++ b/net/dccp/sysctl.c @@ -41,13 +41,6 @@ static struct ctl_table dccp_default_table[] = { .proc_handler = proc_dointvec, }, { - .procname = "ack_ratio", - .data = &sysctl_dccp_feat_ack_ratio, - .maxlen = sizeof(sysctl_dccp_feat_ack_ratio), - .mode = 0644, - .proc_handler = proc_dointvec, - }, - { .procname = "send_ackvec", .data = &sysctl_dccp_feat_send_ack_vector, .maxlen = sizeof(sysctl_dccp_feat_send_ack_vector),