From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-24-ewr.dyndns.com (mxout-118-ewr.mailhop.org [216.146.33.118]) by lists.bufferbloat.net (Postfix) with ESMTP id 066002E0271 for ; Tue, 15 Mar 2011 15:40:35 -0700 (PDT) Received: from scan-22-ewr.mailhop.org (scan-22-ewr.local [10.0.141.244]) by mail-24-ewr.dyndns.com (Postfix) with ESMTP id 466D15CDC25 for ; Tue, 15 Mar 2011 22:40:35 +0000 (UTC) X-Spam-Score: -1.0 (-) X-Mail-Handler: MailHop by DynDNS X-Originating-IP: 74.125.82.47 Received: from mail-ww0-f47.google.com (mail-ww0-f47.google.com [74.125.82.47]) by mail-24-ewr.dyndns.com (Postfix) with ESMTP id 8235C5CDB9D for ; Tue, 15 Mar 2011 22:40:30 +0000 (UTC) Received: by wwk4 with SMTP id 4so1155528wwk.28 for ; Tue, 15 Mar 2011 15:40:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:subject:mime-version:content-type:from :in-reply-to:date:cc:content-transfer-encoding:message-id:references :to:x-mailer; bh=GMuFmmJ8WeW3qZd2p2mlYSqgQMiFxtL3TFs1dE13AHw=; b=TU2eNOt7tD69y3wBmjGYnh8F2nRtIWiFAEDv2H8ETTUHkqMha0SDvsyWy9ok7kRzOM HNGIEDllSwvamGE/btdfjy8iUzwIh2e9okyFgioD1iPSK5jNPgBiOfPA3zL6UpySw8sw SDVe4r3sL8aRxz/9H0hKYnj+qcWFTIdZXNNVg= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=subject:mime-version:content-type:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to:x-mailer; b=Y7VCoqMl73saxZP9rXaGYENDAL0hRHTKu6eTfTrF7OLnHMef1MmamUWxp7eY9Vovs4 ZBx2LGZFy6HlgT57J+fNaI2o1SQ2zzXDRJ4o8fyRHdISsE0Ni9scMMBAOKIE93MQccXU 5l7SLIMq0qwPzE4Kic8XL8VSR6fpRlAdqXXdA= Received: by 10.227.30.141 with SMTP id u13mr31038wbc.144.1300228829854; Tue, 15 Mar 2011 15:40:29 -0700 (PDT) Received: from [192.168.239.42] (xdsl-83-150-84-172.nebulazone.fi [83.150.84.172]) by mx.google.com with ESMTPS id n52sm193584wer.24.2011.03.15.15.40.29 (version=TLSv1/SSLv3 cipher=OTHER); Tue, 15 Mar 2011 15:40:29 -0700 (PDT) Mime-Version: 1.0 (Apple Message framework v1082) Content-Type: text/plain; charset=us-ascii From: Jonathan Morton In-Reply-To: <1300228592.2087.2191.camel@tardy> Date: Wed, 16 Mar 2011 00:40:28 +0200 Content-Transfer-Encoding: quoted-printable Message-Id: References: <4D7F4121.40307@freedesktop.org> <20110315175942.GA10064@goldfish> <1300212877.2087.2155.camel@tardy> <20110315183111.GB2542@tuxdriver.com> <29B06777-CC5F-4802-8727-B04F58CDA9E3@gmail.com> <20110315205146.GF2542@tuxdriver.com> <219C7840-ED79-49EA-929D-96C5A6200401@gmail.com> <20110315151946.31e86b46@nehalam> <1300228592.2087.2191.camel@tardy> To: rick.jones2@hp.com X-Mailer: Apple Mail (2.1082) Cc: Stephen Hemminger , bloat@lists.bufferbloat.net Subject: Re: [Bloat] Random idea in reaction to all the discussion of TCP flavours - timestamps? X-BeenThere: bloat@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: General list for discussing Bufferbloat List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 15 Mar 2011 22:40:36 -0000 On 16 Mar, 2011, at 12:36 am, Rick Jones wrote: > Back and forth synchronization between driver and device is > doubleplusungood. Being able to remove a packet on the tx queue = already > made known to the NIC sounds like it could become a rathole. If you = are > lucky, you *might* have a "valid/invalid" bit in a packet descriptor > that the driver could hope to set before the NIC had pulled-in a copy > across the I/O bus. Since this would be on the order of a second after submission, this = seems unlikely then. The even better solution would be if the hardware timed-out an old = packet by itself after about 1 second. Does this happen already? If = not, can it? - Jonathan