From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH] AF_RXRPC: Sort out MTU handling Date: Fri, 04 May 2007 12:42:25 -0700 (PDT) Message-ID: <20070504.124225.111205875.davem@davemloft.net> References: <20070504145647.19125.99441.stgit@warthog.cambridge.redhat.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org To: dhowells@redhat.com Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:45673 "EHLO sunset.davemloft.net" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1161914AbXEDTmj (ORCPT ); Fri, 4 May 2007 15:42:39 -0400 In-Reply-To: <20070504145647.19125.99441.stgit@warthog.cambridge.redhat.com> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org From: David Howells Date: Fri, 04 May 2007 15:56:47 +0100 > Sort out the MTU determination and handling in AF_RXRPC: > > (1) If it's present, parse the additional information supplied by the peer at > the end of the ACK packet (struct ackinfo) to determine the MTU sizes > that peer is willing to support. > > (2) Initialise the MTU size to that peer from the kernel's routing records. > > (3) Send ACKs rather than ACKALLs as the former carry the additional info, > and the latter do not. > > (4) Declare the interface MTU size in outgoing ACKs as a maximum amount of > data that can be stuffed into an RxRPC packet without it having to be > fragmented to come in this computer's NIC. > > (5) If sendmsg() is given MSG_MORE then it should allocate an skb of the > maximum size rather than one just big enough for the data it's got left > to process on the theory that there is more data to come that it can > append to that packet. > > This means, for example, that if AFS does a large StoreData op, all the > packets barring the last will be filled to the maximum unfragmented size. > > Signed-off-by: David Howells Applied, thanks.