Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755902AbaAVTEE (ORCPT ); Wed, 22 Jan 2014 14:04:04 -0500 Received: from smtp.citrix.com ([66.165.176.89]:55490 "EHLO SMTP.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755673AbaAVTDr (ORCPT ); Wed, 22 Jan 2014 14:03:47 -0500 X-IronPort-AV: E=Sophos;i="4.95,701,1384300800"; d="scan'208";a="95452172" Message-ID: <52E015F5.70408@citrix.com> Date: Wed, 22 Jan 2014 19:03:17 +0000 From: Zoltan Kiss User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.2.0 MIME-Version: 1.0 To: Stefano Stabellini CC: , , , , , Subject: Re: [Xen-devel] [PATCH v4] xen/grant-table: Avoid m2p_override during mapping References: <1390335755-29328-1-git-send-email-zoltan.kiss@citrix.com> <52E00FB7.3040508@citrix.com> In-Reply-To: Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.80.2.133] X-DLP: MIA1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 22/01/14 18:50, Stefano Stabellini wrote: > On Wed, 22 Jan 2014, Zoltan Kiss wrote: >> On 22/01/14 16:39, Stefano Stabellini wrote: >>> On Tue, 21 Jan 2014, Zoltan Kiss wrote: >>>> @@ -121,7 +125,7 @@ static inline unsigned long mfn_to_pfn(unsigned long >>>> mfn) >>>> pfn = m2p_find_override_pfn(mfn, ~0); >>>> } >>>> >>>> - /* >>>> + /* >>> >>> Spurious change? >> It removes a stray space from the original code. Not necessary, but if it's >> there, I think we can keep it. > > Usually cosmetic changes are done in a separate patch, or at the very > least they are mentioned in the commit message. Ok, I'll mention it. > > >>>> diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c >>>> index 2ae8699..0060178 100644 >>>> --- a/arch/x86/xen/p2m.c >>>> +++ b/arch/x86/xen/p2m.c >>>> @@ -872,15 +872,13 @@ static unsigned long mfn_hash(unsigned long mfn) >>>> >>>> /* Add an MFN override for a particular page */ >>>> int m2p_add_override(unsigned long mfn, struct page *page, >>>> - struct gnttab_map_grant_ref *kmap_op) >>>> + struct gnttab_map_grant_ref *kmap_op, unsigned long pfn) >>> >>> Do we really need to add another additional parameter to >>> m2p_add_override? >>> I would just let m2p_add_override and m2p_remove_override call >>> page_to_pfn again. It is not that expensive. >> Yes, because that page_to_pfn can return something different. That's why the >> v2 patches failed. > > I am really curious: how can page_to_pfn return something different? > I don't think is supposed to happen. You call set_phys_to_machine before calling m2p* functions. Zoli -- 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/