From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752184AbeDJQoO (ORCPT ); Tue, 10 Apr 2018 12:44:14 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:33614 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751367AbeDJQoM (ORCPT ); Tue, 10 Apr 2018 12:44:12 -0400 Subject: Re: [PATCH v2 2/2] mm: remove odd HAVE_PTE_SPECIAL To: Robin Murphy , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, x86@kernel.org, linux-doc@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, Jerome Glisse , mhocko@kernel.org, aneesh.kumar@linux.vnet.ibm.com, akpm@linux-foundation.org, mpe@ellerman.id.au, benh@kernel.crashing.org, paulus@samba.org, Jonathan Corbet , Catalin Marinas , Will Deacon , Yoshinori Sato , Rich Felker , "David S . Miller" , Thomas Gleixner , Ingo Molnar , Vineet Gupta , Palmer Dabbelt , Albert Ou , Martin Schwidefsky , Heiko Carstens , David Rientjes References: <1523373951-10981-1-git-send-email-ldufour@linux.vnet.ibm.com> <1523373951-10981-3-git-send-email-ldufour@linux.vnet.ibm.com> <3f20ac8b-20b8-f052-bc44-dcc0316354ca@arm.com> From: Laurent Dufour Date: Tue, 10 Apr 2018 18:44:00 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: <3f20ac8b-20b8-f052-bc44-dcc0316354ca@arm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 x-cbid: 18041016-0044-0000-0000-00000545A849 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18041016-0045-0000-0000-00002885D963 Message-Id: <1521dc0e-e9f8-d10f-e213-1b1552eb03fa@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-04-10_06:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1804100159 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/04/2018 17:58, Robin Murphy wrote: > On 10/04/18 16:25, Laurent Dufour wrote: >> Remove the additional define HAVE_PTE_SPECIAL and rely directly on >> CONFIG_ARCH_HAS_PTE_SPECIAL. >> >> There is no functional change introduced by this patch >> >> Signed-off-by: Laurent Dufour >> --- >>   mm/memory.c | 23 ++++++++++------------- >>   1 file changed, 10 insertions(+), 13 deletions(-) >> >> diff --git a/mm/memory.c b/mm/memory.c >> index 96910c625daa..53b6344a90d2 100644 >> --- a/mm/memory.c >> +++ b/mm/memory.c >> @@ -817,19 +817,13 @@ static void print_bad_pte(struct vm_area_struct *vma, >> unsigned long addr, >>    * PFNMAP mappings in order to support COWable mappings. >>    * >>    */ >> -#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL >> -# define HAVE_PTE_SPECIAL 1 >> -#else >> -# define HAVE_PTE_SPECIAL 0 >> -#endif >>   struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr, >>                    pte_t pte, bool with_public_device) >>   { >>       unsigned long pfn = pte_pfn(pte); >>   -    if (HAVE_PTE_SPECIAL) { >> -        if (likely(!pte_special(pte))) >> -            goto check_pfn; >> +#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL > > Nit: Couldn't you use IS_ENABLED(CONFIG_ARCH_HAS_PTE_SPECIAL) within the > existing code structure to avoid having to add these #ifdefs? I agree, that would be better. I didn't thought about this option.. Thanks for reporting this.