From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anshuman Khandual Subject: Re: [PATCH] mm/pgtable: Move extern zero_pfn outside __HAVE_COLOR_ZERO_PAGE Date: Tue, 16 Jun 2020 10:54:17 +0530 Message-ID: References: <1592280498-15442-1-git-send-email-anshuman.khandual@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: Received: from foss.arm.com ([217.140.110.172]:59462 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726161AbgFPFYb (ORCPT ); Tue, 16 Jun 2020 01:24:31 -0400 In-Reply-To: <1592280498-15442-1-git-send-email-anshuman.khandual@arm.com> Content-Language: en-US Sender: linux-arch-owner@vger.kernel.org List-ID: To: linux-mm@kvack.org Cc: Arnd Bergmann , linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, Andrew Morton , Mike Rapoport , "Kirill A . Shutemov" On 06/16/2020 09:38 AM, Anshuman Khandual wrote: > zero_pfn variable is required whether __HAVE_COLOR_ZERO_PAGE is enabled > or not. Also it should not really be declared individually in all functions > where it gets used. Just move the declaration outside, which also makes it > available for other potential users. > > Cc: Arnd Bergmann > Cc: linux-arch@vger.kernel.org > Cc: linux-mm@kvack.org > Cc: linux-kernel@vger.kernel.org > Signed-off-by: Anshuman Khandual > --- > Applies on 5.8-rc1. If the earlier motivation was to hide zero_pfn from > general visibility, we could just put in a comment and update the commit > message that my_zero_pfn() should always be used rather than zero_pfn. > Build tested on many platforms and boot tested on arm64, x86. > > include/linux/pgtable.h | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h > index 32b6c52d41b9..078e9864abca 100644 > --- a/include/linux/pgtable.h > +++ b/include/linux/pgtable.h > @@ -1020,10 +1020,11 @@ extern void untrack_pfn(struct vm_area_struct *vma, unsigned long pfn, > extern void untrack_pfn_moved(struct vm_area_struct *vma); > #endif > > +extern unsigned long zero_pfn; > + > #ifdef __HAVE_COLOR_ZERO_PAGE > static inline int is_zero_pfn(unsigned long pfn) > { > - extern unsigned long zero_pfn; > unsigned long offset_from_zero_pfn = pfn - zero_pfn; > return offset_from_zero_pfn <= (zero_page_mask >> PAGE_SHIFT); > } > @@ -1033,13 +1034,11 @@ static inline int is_zero_pfn(unsigned long pfn) > #else > static inline int is_zero_pfn(unsigned long pfn) > { > - extern unsigned long zero_pfn; > return pfn == zero_pfn; > } > > static inline unsigned long my_zero_pfn(unsigned long addr) > { > - extern unsigned long zero_pfn; > return zero_pfn; > } > #endif > The CC list is incomplete. Adding Andrew, Mike and Kirill. +Cc: Andrew Morton +Cc: Mike Rapoport +Cc: Kirill A . Shutemov Will update the CC list next time around. - Anshuman