Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752182AbYKRFVo (ORCPT ); Tue, 18 Nov 2008 00:21:44 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750735AbYKRFVg (ORCPT ); Tue, 18 Nov 2008 00:21:36 -0500 Received: from accolon.hansenpartnership.com ([76.243.235.52]:53634 "EHLO accolon.hansenpartnership.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750715AbYKRFVg (ORCPT ); Tue, 18 Nov 2008 00:21:36 -0500 Subject: Re: pci_map_sg() does not coalesce adjacent physical memory? x86 From: James Bottomley To: Andrew Morton Cc: Leon Woestenberg , LKML , FUJITA Tomonori , Tejun Heo In-Reply-To: <20081117191532.c1c849f5.akpm@linux-foundation.org> References: <20081117191532.c1c849f5.akpm@linux-foundation.org> Content-Type: text/plain Date: Tue, 18 Nov 2008 14:21:29 +0900 Message-Id: <1226985689.3403.20.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.22.3.1 (2.22.3.1-1.fc9) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 728 Lines: 25 On Mon, 2008-11-17 at 19:15 -0800, Andrew Morton wrote: > (cc's added) > > On Mon, 17 Nov 2008 22:54:33 +0100 "Leon Woestenberg" wrote: > > > Hello, > > > > pci_map_sg() does not coalesce the scattergather list for me on x86. > > In which kernel version(s)? Also which driver? Some manually disable physical merging, so they will never coalesce adjacent pages. You need the flag QUEUE_FLAG_CLUSTER set for physical merging to take place. James -- 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/