From: Alan Cox Subject: Re: [PATCH] zerocopy NFS for 2.5.36 Date: 19 Sep 2002 00:54:37 +0100 Sender: nfs-admin@lists.sourceforge.net Message-ID: <1032393277.24895.8.camel@irongate.swansea.linux.org.uk> References: <20020918.171431.24608688.taka@valinux.co.jp> <20020918.160057.17194839.davem@redhat.com> Mime-Version: 1.0 Content-Type: text/plain Cc: taka@valinux.co.jp, neilb@cse.unsw.edu.au, linux-kernel@vger.kernel.org, nfs@lists.sourceforge.net Return-path: Received: from pc1-cwma1-5-cust128.swa.cable.ntl.com ([80.5.120.128] helo=irongate.swansea.linux.org.uk) by usw-sf-list1.sourceforge.net with esmtp (Cipher TLSv1:DES-CBC3-SHA:168) (Exim 3.31-VA-mm2 #1 (Debian)) id 17rodN-00085g-00 for ; Wed, 18 Sep 2002 16:53:29 -0700 To: "David S. Miller" In-Reply-To: <20020918.160057.17194839.davem@redhat.com> Errors-To: nfs-admin@lists.sourceforge.net List-Help: List-Post: List-Subscribe: , List-Id: Discussion of NFS under Linux development, interoperability, and testing. List-Unsubscribe: , List-Archive: On Thu, 2002-09-19 at 00:00, David S. Miller wrote: > It was discussed long ago that csum_and_copy_from_user() performs > better than plain copy_from_user() on x86. I do not remember all The better was a freak of PPro/PII scheduling I think > details, but I do know that using copy_from_user() is not a real > improvement at least on x86 architecture. The same as bit is easy to explain. Its totally memory bandwidth limited on current x86-32 processors. (Although I'd welcome demonstrations to the contrary on newer toys) ------------------------------------------------------- This SF.NET email is sponsored by: AMD - Your access to the experts on Hammer Technology! Open Source & Linux Developers, register now for the AMD Developer Symposium. Code: EX8664 http://www.developwithamd.com/developerlab _______________________________________________ NFS maillist - NFS@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nfs