From owner-freebsd-net@FreeBSD.ORG Tue Apr 19 12:08:30 2005 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 71AB416A4CE for ; Tue, 19 Apr 2005 12:08:30 +0000 (GMT) Received: from c00l3r.networx.ch (c00l3r.networx.ch [62.48.2.2]) by mx1.FreeBSD.org (Postfix) with ESMTP id 72AD743D62 for ; Tue, 19 Apr 2005 12:08:29 +0000 (GMT) (envelope-from andre@freebsd.org) Received: (qmail 47785 invoked from network); 19 Apr 2005 12:10:43 -0000 Received: from unknown (HELO freebsd.org) ([62.48.0.53]) (envelope-sender ) by c00l3r.networx.ch (qmail-ldap-1.03) with SMTP for ; 19 Apr 2005 12:10:43 -0000 Message-ID: <4264F4BC.4F3B57AE@freebsd.org> Date: Tue, 19 Apr 2005 14:08:28 +0200 From: Andre Oppermann X-Mailer: Mozilla 4.8 [en] (Windows NT 5.0; U) X-Accept-Language: en MIME-Version: 1.0 To: Gleb Smirnoff References: <20050419064747.GC734@cell.sick.ru> <4264D430.D39B81D0@freebsd.org> <20050419120324.GA5862@cell.sick.ru> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit cc: net@FreeBSD.org Subject: Re: if_link_state_change() patch for review X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 19 Apr 2005 12:08:30 -0000 Gleb Smirnoff wrote: > A> You have to be careful here indeed. If the link is rapidly flapping > A> then you only want to report changes in status. For example when > A> it going down, up, down and all these events got queued it doesn't > A> make sense to report down->down. This could indeed confuse some > A> tools and isn't very useful. Either you check the first event vs. > A> the last one if there is a change in state or you just take the events > A> as trigger to have a look at the interface status when the ithread > A> runs. There however you'd have to track the previous state to detect > A> changes. > > I do not know any applications which would be confused, yet. Also, while > event coalescing is possible theoretically, I failed to reproduce it. I've > added a debugging printf, so we will see if anyone experiences these > coalescing events at all. It doesn't really make sense, so we better don't do it and document that fact. -- Andre