From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Grover Subject: Re: [PATCH 03/21] RDS: Congestion-handling code Date: Tue, 27 Jan 2009 11:10:49 -0800 Message-ID: References: <1233022678-9259-1-git-send-email-andy.grover@oracle.com> <1233022678-9259-4-git-send-email-andy.grover@oracle.com> <20090127131049.GE2646@ioremap.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Andy Grover , rdreier@cisco.com, rds-devel@oss.oracle.com, general@lists.openfabrics.org, netdev@vger.kernel.org To: Evgeniy Polyakov Return-path: Received: from wf-out-1314.google.com ([209.85.200.169]:38977 "EHLO wf-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755303AbZA0TKt (ORCPT ); Tue, 27 Jan 2009 14:10:49 -0500 Received: by wf-out-1314.google.com with SMTP id 27so7629403wfd.4 for ; Tue, 27 Jan 2009 11:10:49 -0800 (PST) In-Reply-To: <20090127131049.GE2646@ioremap.net> Sender: netdev-owner@vger.kernel.org List-ID: On Tue, Jan 27, 2009 at 5:10 AM, Evgeniy Polyakov wrote: > On Mon, Jan 26, 2009 at 06:17:40PM -0800, Andy Grover (andy.grover@oracle.com) wrote: >> +/* >> + * Yes, a global lock. It's used so infrequently that it's worth keeping it >> + * global to simplify the locking. It's only used in the following >> + * circumstances: >> + * >> + * - on connection buildup to associate a conn with its maps > > Is this a rare condition? Is this protocol only intended for the > long-living connections and is not suitable for the cases when lots of > them are created and teared down quickly? Connections are long-lived. Imagine a cluster. RDS multiplexes all sockets' datagrams between 2 hosts over a single transport-layer connection, so if a node sends ONE datagram to another, an IB connection is set up and sticks around indefinitely. Regards -- Andy