Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932104AbaAVSva (ORCPT ); Wed, 22 Jan 2014 13:51:30 -0500 Received: from smtp.citrix.com ([66.165.176.89]:43147 "EHLO SMTP.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752310AbaAVSv2 (ORCPT ); Wed, 22 Jan 2014 13:51:28 -0500 X-IronPort-AV: E=Sophos;i="4.95,701,1384300800"; d="scan'208";a="95446297" Date: Wed, 22 Jan 2014 18:50:20 +0000 From: Stefano Stabellini X-X-Sender: sstabellini@kaball.uk.xensource.com To: Zoltan Kiss CC: Stefano Stabellini , , , , , , Subject: Re: [Xen-devel] [PATCH v4] xen/grant-table: Avoid m2p_override during mapping In-Reply-To: <52E00FB7.3040508@citrix.com> Message-ID: References: <1390335755-29328-1-git-send-email-zoltan.kiss@citrix.com> <52E00FB7.3040508@citrix.com> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" X-DLP: MIA1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. > > > 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. -- 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/