From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932220AbWDYNyR (ORCPT ); Tue, 25 Apr 2006 09:54:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932223AbWDYNyR (ORCPT ); Tue, 25 Apr 2006 09:54:17 -0400 Received: from e6.ny.us.ibm.com ([32.97.182.146]:3239 "EHLO e6.ny.us.ibm.com") by vger.kernel.org with ESMTP id S932220AbWDYNyQ (ORCPT ); Tue, 25 Apr 2006 09:54:16 -0400 Date: Tue, 25 Apr 2006 08:58:10 -0500 From: Jon Mason To: Muli Ben-Yehuda Cc: Andi Kleen , linux-kernel@vger.kernel.org Subject: Re: [PATCH] x86-64: trivial gart clean-up Message-ID: <20060425135810.GA7779@us.ibm.com> References: <20060424225342.GB14575@us.ibm.com> <200604250042.43910.ak@suse.de> <20060425052607.GC28558@granada.merseine.nu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20060425052607.GC28558@granada.merseine.nu> User-Agent: Mutt/1.5.11 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 25, 2006 at 08:26:07AM +0300, Muli Ben-Yehuda wrote: > On Tue, Apr 25, 2006 at 12:42:43AM +0200, Andi Kleen wrote: > > > On Tuesday 25 April 2006 00:53, Jon Mason wrote: > > > A trivial change to have gart_unmap_sg call gart_unmap_single directly, > > > instead of bouncing through the dma_unmap_single wrapper in > > > dma-mapping.h. This change required moving the gart_unmap_single above > > > gart_unmap_sg, and under gart_map_single (which seems a more logical > > > place that its current location IMHO). > > > > What advantage does that have? I think I prefer the old code. > > I don't know what Jon had in mind, but we do avoid a call through a > function pointer this way. I agree with Jon that it also makes more > sense - gart code can just call the gart code directly, without going > through the dma_xxx wrapper that ends up calling it anyway. Yes, that is exactly what I was trying to say in my comment above. Sorry for the confusion, and thanks for clearing it up Muli. The dma_unmap_single call is the only dma_XXX type call in the gart code. All other calls use the gart_XXX equivalent. It seems to me that this was an oversight. Also, the dma_XXX type calls go through a wrapper in asm/dma-mapping.h, which translates this call to the gart equivalent. It also makes the code 8 bytes smaller :) Thanks, Jon > > Cheers, > Muli > -- > Muli Ben-Yehuda > http://www.mulix.org | http://mulix.livejournal.com/ >