From: Chuck Lever Subject: Re: splice read byte accounting Date: Thu, 28 Jan 2010 10:07:02 -0500 Message-ID: References: <39A11474-A44E-49FE-8135-54B384254311@oracle.com> <1264634364.3788.177.camel@localhost> Mime-Version: 1.0 (Apple Message framework v936) Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Cc: Linux NFS Mailing List To: Trond Myklebust Return-path: Received: from acsinet12.oracle.com ([141.146.126.234]:16998 "EHLO acsinet12.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753014Ab0A1PHj (ORCPT ); Thu, 28 Jan 2010 10:07:39 -0500 In-Reply-To: <1264634364.3788.177.camel@localhost> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Jan 27, 2010, at 6:19 PM, Trond Myklebust wrote: > On Wed, 2010-01-27 at 17:22 -0500, Chuck Lever wrote: >> Hi- >> >> nfs_file_splice_write() accounts for the bytes in the request in the >> "normal bytes written" counter, but nfs_file_splice_read() does not >> account for bytes read. >> >> Should the read path count these as normal bytes as well, or should >> the write path not account for these bytes? >> > > nfs_file_splice_read() should probably update NFSIOS_NORMALREADBYTES. > > That said, why do nfs_file_read(), nfs_file_write() and > nfs_file_splice_write() update the stats with the requested number of > bytes, irrespective of the number of bytes that were actually > read/write? We're counting the number of bytes requested by applications. I'm not sure which is more useful here; number of bytes requested, or number of bytes actually read/written. For computing ratios of app bytes v. otw bytes, I suppose the latter? -- Chuck Lever chuck[dot]lever[at]oracle[dot]com