Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754639Ab1C2VWE (ORCPT ); Tue, 29 Mar 2011 17:22:04 -0400 Received: from opensource.wolfsonmicro.com ([80.75.67.52]:46155 "EHLO opensource2.wolfsonmicro.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752809Ab1C2VWC (ORCPT ); Tue, 29 Mar 2011 17:22:02 -0400 Date: Wed, 30 Mar 2011 06:22:11 +0900 From: Mark Brown To: Will Simoneau Cc: Chuck Lever , Belisko Marek , Trond.Myklebust@netapp.com, bdowning@lavos.net, linux-nfs@vger.kernel.org, LKML Subject: Re: [bisect] kernel 2.6.38 regression with root nfs mounting Message-ID: <20110329212210.GB30482@opensource.wolfsonmicro.com> References: <43F07477-9075-444D-9BBB-368650538EA8@oracle.com> <977C528D-4540-4EB2-92F9-6DAF357D8C81@oracle.com> <8F19F0FE-0800-4C45-B857-1C682CF6A30D@oracle.com> <4AD2FFC1-E777-4C29-8718-4E1717EFCD86@oracle.com> <20110329202408.GM1966@ele.uri.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110329202408.GM1966@ele.uri.edu> X-Cookie: You are standing on my toes. User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1055 Lines: 19 On Tue, Mar 29, 2011 at 04:24:08PM -0400, Will Simoneau wrote: > Interestingly, we are both using DM9000 network chips. I wonder if there > is a UDP-related problem on the DM9000. I will play with my > configuration a little more (in particular testing proto=tcp and revert > of 53d4737580535e073963b91ce87d4216e434fab5) but my guess is the DM9000 > driver/chip is to blame. The DM9000A on my board has 16K of on-chip SRAM > used for its RX/TX buffers which may be playing a part in the problem. It's more likely that the DM9000 is just slow and fragile. One thing to note with a lot of the lower end network chips is that you end up needing to specify rsize and wsize so that you don't get fragmentation - about 1k tends to work well IME. Otherwise performance often degrades to the point of unusability. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/