Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758361Ab2CACyi (ORCPT ); Wed, 29 Feb 2012 21:54:38 -0500 Received: from mail-yw0-f46.google.com ([209.85.213.46]:37036 "EHLO mail-yw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756523Ab2CACyf convert rfc822-to-8bit (ORCPT ); Wed, 29 Feb 2012 21:54:35 -0500 Authentication-Results: mr.google.com; spf=pass (google.com: domain of yhlu.kernel@gmail.com designates 10.236.184.226 as permitted sender) smtp.mail=yhlu.kernel@gmail.com; dkim=pass header.i=yhlu.kernel@gmail.com MIME-Version: 1.0 In-Reply-To: References: <1330556858-11768-1-git-send-email-yinghai@kernel.org> <1330556858-11768-3-git-send-email-yinghai@kernel.org> Date: Wed, 29 Feb 2012 18:54:34 -0800 X-Google-Sender-Auth: B-OPmr-_36vZpJMJpJ4A9Z18DRE Message-ID: Subject: Re: [PATCH 02/39] x86, PCI: have own version for pcibios_bus_to_resource From: Yinghai Lu To: Bjorn Helgaas Cc: Jesse Barnes , Benjamin Herrenschmidt , Tony Luck , David Miller , x86 , Dominik Brodowski , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1694 Lines: 42 On Wed, Feb 29, 2012 at 4:42 PM, Bjorn Helgaas wrote: > On Wed, Feb 29, 2012 at 4:33 PM, Yinghai Lu wrote: >> On Wed, Feb 29, 2012 at 3:20 PM, Bjorn Helgaas wrote: >>> On Wed, Feb 29, 2012 at 4:07 PM, Yinghai Lu wrote: >>>> x86 does not need to offset the address. So we can skip that costing offset >>>> searching. >>> >>> I tried to start a discussion about this patch (and others), but I >>> don't think you responded: >>> http://marc.info/?l=linux-pci&m=133036414506921&w=2 >> >> this patch does reduce some not needed ops. >> >> and it does not affects your effects, > > It does affect my efforts in that this patch adds back x86 complexity > that I don't think is necessary. > > And this patch makes it so the pci_add_resource_offset() interface > exists and appears to work on x86, but if somebody tries to use it, it > *doesn't* work. ?I don't like to write code like that. ?I think it's > poor style. > >> and it just make x86 not get punished. > > What punishment are you worried about? ?I really don't think you'll be > able to measure any performance impact. > > I agree that the x86 code you add *is* simpler than the generic > version. ?But I think the *overall* complexity is higher because now > you have to look at two versions (generic and x86) and convince > yourself that it's safe to use the x86 version. > fine, i will that patch. Yinghai -- 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/