From mboxrd@z Thu Jan 1 00:00:00 1970 From: lsorense@csclub.uwaterloo.ca (Lennart Sorensen) Subject: Re: Re: Strange connection slowdown on pcnet32 Date: Tue, 20 Feb 2007 16:44:33 -0500 Message-ID: <20070220214433.GA22467@csclub.uwaterloo.ca> References: <32943920.1119801171642884331.JavaMail.root@vms226.mailsrvcs.net> <20070216172110.GC7582@csclub.uwaterloo.ca> <20070216202300.GD7585@csclub.uwaterloo.ca> <20070216210157.GE7585@csclub.uwaterloo.ca> <20070219201136.GH7585@csclub.uwaterloo.ca> <20070219221845.GI7585@csclub.uwaterloo.ca> <20070219222920.GJ7585@csclub.uwaterloo.ca> <20070219234548.GK7585@csclub.uwaterloo.ca> <20070219235916.GL7585@csclub.uwaterloo.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: netdev@vger.kernel.org To: pcnet32@verizon.net Return-path: Received: from caffeine.uwaterloo.ca ([129.97.134.17]:53453 "EHLO caffeine.csclub.uwaterloo.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030430AbXBTVoe (ORCPT ); Tue, 20 Feb 2007 16:44:34 -0500 Content-Disposition: inline In-Reply-To: <20070219235916.GL7585@csclub.uwaterloo.ca> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Mon, Feb 19, 2007 at 06:59:16PM -0500, Lennart Sorensen wrote: > I am also noticing the receive error count going up, and the source is > this code: > > if (status & 0x01) /* Only count a general error at the */ > lp->stats.rx_errors++; /* end of a packet. */ > > It appears this means I am receiving a frame marked with "End Of Packet" > but without "Start of Packet". I have no idea how that happens, but it > shouldn't be able to make the driver and MAC stop processing the receive > ring. Well the packets actually have both start and end marked, but also have overflow marked, so the cpu simply isn't keeping up it seems (It is taking about 100% of the cpu to push through 6500KB/s). Certainly the CONFIG_X86_OOSTORE makes a major difference, although I am still not sure why. Simply skipping ahead one or two receive descriptors when the current one is marked as owned by the MAC but the one a few ahead is owned by the CPU allows it to continue receiving when it happens. I really want to find out why it happens though, although I am not sure how to go about doing that. -- Len Sorensen