From owner-freebsd-net Sat Jul 29 10:25:41 2000 Delivered-To: freebsd-net@freebsd.org Received: from mail-out2.apple.com (mail-out2.apple.com [17.254.0.51]) by hub.freebsd.org (Postfix) with ESMTP id 5249B37B60A for ; Sat, 29 Jul 2000 10:25:21 -0700 (PDT) (envelope-from justin@apple.com) Received: from mailgate1.apple.com (A17-128-100-225.apple.com [17.128.100.225]) by mail-out2.apple.com (8.9.3/8.9.3) with ESMTP id KAA07470 for ; Sat, 29 Jul 2000 10:25:16 -0700 (PDT) Received: from scv1.apple.com (scv1.apple.com) by mailgate1.apple.com (Content Technologies SMTPRS 4.1.5) with ESMTP id for ; Sat, 29 Jul 2000 10:25:16 -0700 Received: from grinch ([17.219.158.67]) by scv1.apple.com (8.9.3/8.9.3) with SMTP id KAA11439 for ; Sat, 29 Jul 2000 10:25:12 -0700 (PDT) Message-Id: <200007291725.KAA11439@scv1.apple.com> To: freebsd-net@freebsd.org Subject: Re: sub-optimal tcp_ouput() performance in the face of ENOBUFS Date: Sat, 29 Jul 2000 10:26:14 -0700 From: "Justin C. Walker" Reply-To: justin@apple.com x-mailer: Apple Mail (2.317) Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Friday, July 28, 2000, at 07:58 PM, Mike Silbersack wrote: > > On Fri, 28 Jul 2000, Archie Cobbs wrote: > > > I understand the scenario described by the commit message. What > > I don't understand about this commit is this: suppose the exact > > same scenario happens, except that instead of ip_output() returning > > ENOBUFS, it returns zero, BUT the packet is dropped anyway because > > of (say) an Ethernet collision. > > > > Then why wouldn't you have the same thing happen, i.e., no retransmit > > timer running and you're stuck in LAST_ACK forever? No timer is being > > set in the subsequent code at the end of tcp_output().. > > Hm, I was going to wager that some calling procedure was acting > differently depending on the return value of tcp_output, but since ENOBUFS > returns 0, and the error isn't checked anyway. Forgive my early-morning density, but I've read this sentence several times, and it just doesn't look right. Could you try again? I know there's value in it, but it isn't making it through. Regards, Justin To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message