Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 8 Aug 2002 18:13:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 8 Aug 2002 18:13:20 -0400 Received: from zcars04e.nortelnetworks.com ([47.129.242.56]:50137 "EHLO zcars04e.ca.nortel.com") by vger.kernel.org with ESMTP id ; Thu, 8 Aug 2002 18:13:19 -0400 Message-ID: <3D52EDD6.75150466@nortelnetworks.com> Date: Thu, 08 Aug 2002 18:16:54 -0400 From: Chris Friesen X-Mailer: Mozilla 4.77 [en] (X11; U; Linux 2.4.18 i686) X-Accept-Language: en MIME-Version: 1.0 To: linux-kernel@vger.kernel.org Subject: flushing arp buffer -- why __skb_dequeue rather than __skb_dequeue_tail ? Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1286 Lines: 27 As part of one of our test cases we ran into a scenario where we were sending out messages while waiting on an arp reply. As expected they were buffered, but we noticed that after the reply was received the packets were sent out in LIFO order. In neigh_update() in neighbor.c, we're looping through the list calling __skb_dequeue(). Is there any particular reason why this was chosen rather than __skb_dequeue_tail()? The latter would result in FIFO flushing of the buffer which could have some benefits to udp applications that retry on out-of-order message receipt, and it doesn't seem to be many more instructions, if any. Besides, this isn't the fast path so a few extra instructions shouldn't matter. Would you anticipate any odd side effects if we did change to FIFO flushing? Chris -- Chris Friesen | MailStop: 043/33/F10 Nortel Networks | work: (613) 765-0557 3500 Carling Avenue | fax: (613) 765-2986 Nepean, ON K2H 8E9 Canada | email: cfriesen@nortelnetworks.com - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/