From mboxrd@z Thu Jan 1 00:00:00 1970 From: jamal Subject: Re: [PATCH 2/3][NET_BATCH] net core use batching Date: Mon, 08 Oct 2007 09:17:24 -0400 Message-ID: <1191849444.4352.29.camel@localhost> References: Reply-To: hadi@cyberus.ca Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: David Miller , gaagaan@gmail.com, general@lists.openfabrics.org, herbert@gondor.apana.org.au, jagana@us.ibm.com, jeff@garzik.org, johnpol@2ka.mipt.ru, Patrick McHardy , kumarkr@linux.ibm.com, mcarlson@broadcom.com, mchan@broadcom.com, netdev@vger.kernel.org, peter.p.waskiewicz.jr@intel.com, randy.dunlap@oracle.com, rdreier@cisco.com, rick.jones2@hp.com, Robert.Olsson@data.slu.se, shemminger@linux-foundation.org, sri@us.ibm.com, tgraf@suug.ch, xma@us.ibm.com To: Krishna Kumar2 Return-path: Received: from wx-out-0506.google.com ([66.249.82.237]:61135 "EHLO wx-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753574AbXJHNRj (ORCPT ); Mon, 8 Oct 2007 09:17:39 -0400 Received: by wx-out-0506.google.com with SMTP id h31so1316474wxd for ; Mon, 08 Oct 2007 06:17:38 -0700 (PDT) In-Reply-To: Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Mon, 2007-08-10 at 10:33 +0530, Krishna Kumar2 wrote: > > As a side note: Any batching driver should _never_ have to requeue; if > > it does it is buggy. And the non-batching ones if they ever requeue will > > be a single packet, so not much reordering. > > On the contrary, batching LLTX drivers (if that is not ruled out) will very > often requeue resulting in heavy reordering. Fix looks good though. Two things: one, LLTX is deprecated (I think i saw a patch which says no more new drivers should do LLTX) and i plan if nobody else does to kill LLTX in e1000 RSN. So for that reason i removed all code that existed to support LLTX. two, there should _never_ be any requeueing even if LLTX in the previous patches when i supported them; if there is, it is a bug. This is because we dont send more than what the driver asked for via xmit_win. So if it asked for more than it can handle, that is a bug. If its available space changes while we are sending to it, that too is a bug. cheers, jamal