Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757939AbYGNViA (ORCPT ); Mon, 14 Jul 2008 17:38:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753325AbYGNVhv (ORCPT ); Mon, 14 Jul 2008 17:37:51 -0400 Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:39813 "EHLO sunset.davemloft.net" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1753295AbYGNVhv (ORCPT ); Mon, 14 Jul 2008 17:37:51 -0400 Date: Mon, 14 Jul 2008 14:37:51 -0700 (PDT) Message-Id: <20080714.143751.266098047.davem@davemloft.net> To: mpatocka@redhat.com Cc: andi@firstfloor.org, sparclinux@vger.kernel.org, linux-kernel@vger.kernel.org, jens.axboe@oracle.com Subject: Re: [SUGGESTION]: drop virtual merge accounting in I/O requests From: David Miller In-Reply-To: References: <20080714.052859.88212003.davem@davemloft.net> X-Mailer: Mew version 5.2 on Emacs 22.1 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1033 Lines: 26 From: Mikulas Patocka Date: Mon, 14 Jul 2008 10:03:29 -0400 (EDT) > On Mon, 14 Jul 2008, David Miller wrote: > > > From: Mikulas Patocka > > Date: Mon, 14 Jul 2008 08:16:13 -0400 (EDT) > > > >> As you mentioned ESP driver, it declares .sg_tablesize = SG_ALL, so > >> BIO_VMERGE_BOUNDARY has no effect on the operation of this driver. Any > >> other driver where BIO_VMERGE_BOUNDARY does matter? > > > > When BIO_VMERGE_BOUNDARY is turned on, requests that would not > > otherwise fit into the device's limits, can. > > Why would someone want to overshoot SG_ALL? ... and, shouldn't the > constant be increased then --- instead of making buggy BIO_VMERGE_BOUNDARY > expectations? I'm talking about other devices, not about the ESP, here. -- 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/