From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6F124C433EF for ; Wed, 11 May 2022 03:59:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234940AbiEKD7h (ORCPT ); Tue, 10 May 2022 23:59:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50152 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229584AbiEKD7c (ORCPT ); Tue, 10 May 2022 23:59:32 -0400 Received: from out30-54.freemail.mail.aliyun.com (out30-54.freemail.mail.aliyun.com [115.124.30.54]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C7A10229FD5; Tue, 10 May 2022 20:59:28 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R161e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04423;MF=baolin.wang@linux.alibaba.com;NM=1;PH=DS;RN=31;SR=0;TI=SMTPD_---0VCu38tE_1652241558; Received: from 30.30.99.144(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0VCu38tE_1652241558) by smtp.aliyun-inc.com(127.0.0.1); Wed, 11 May 2022 11:59:22 +0800 Message-ID: <84209c7b-ac3e-fa3b-75fc-d76ec7c99d68@linux.alibaba.com> Date: Wed, 11 May 2022 11:59:57 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.8.1 Subject: Re: [PATCH v3 2/3] mm: rmap: Fix CONT-PTE/PMD size hugetlb issue when migration To: Andrew Morton , mike.kravetz@oracle.com, catalin.marinas@arm.com, will@kernel.org, songmuchun@bytedance.com, tsbogend@alpha.franken.de, James.Bottomley@HansenPartnership.com, deller@gmx.de, mpe@ellerman.id.au, benh@kernel.crashing.org, paulus@samba.org, hca@linux.ibm.com, gor@linux.ibm.com, agordeev@linux.ibm.com, borntraeger@linux.ibm.com, svens@linux.ibm.com, ysato@users.osdn.me, dalias@libc.org, davem@davemloft.net, arnd@arndb.de, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org References: <20220510161739.fdea4d78dde8471033aab22b@linux-foundation.org> <20220510162847.d9cf3c767e755a54699fb121@linux-foundation.org> From: Baolin Wang In-Reply-To: <20220510162847.d9cf3c767e755a54699fb121@linux-foundation.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 5/11/2022 7:28 AM, Andrew Morton wrote: > On Tue, 10 May 2022 16:17:39 -0700 Andrew Morton wrote: > >>> + >>> +static inline pte_t huge_ptep_clear_flush(struct vm_area_struct *vma, >>> + unsigned long addr, pte_t *ptep) >>> +{ >>> + return ptep_get(ptep); >>> +} >>> + >>> +static inline void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, >>> + pte_t *ptep, pte_t pte) >>> +{ >>> +} >>> #endif /* CONFIG_HUGETLB_PAGE */ >>> >> >> This blows up nommu (arm allnoconfig): >> >> In file included from fs/io_uring.c:71: >> ./include/linux/hugetlb.h: In function 'huge_ptep_clear_flush': >> ./include/linux/hugetlb.h:1100:16: error: implicit declaration of function 'ptep_get' [-Werror=implicit-function-declaration] >> 1100 | return ptep_get(ptep); >> | ^~~~~~~~ >> >> >> huge_ptep_clear_flush() is only used in CONFIG_NOMMU=n files, so I simply >> zapped this change. >> > > Well that wasn't a great success. Doing this instead. It's pretty > nasty - something nicer would be nicer please. Thanks for fixing the building issue. I'll look at this to simplify the dummy function. Myabe just remove the ptep_get(). diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -1097,7 +1097,7 @@ static inline void set_huge_swap_pte_at(struct mm_struct *mm, unsigned long addr static inline pte_t huge_ptep_clear_flush(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep) { - return ptep_get(ptep); + return *ptep; } > > --- a/include/linux/hugetlb.h~mm-rmap-fix-cont-pte-pmd-size-hugetlb-issue-when-migration-fix > +++ a/include/linux/hugetlb.h > @@ -1094,6 +1094,7 @@ static inline void set_huge_swap_pte_at( > { > } > > +#ifdef CONFIG_MMU > static inline pte_t huge_ptep_clear_flush(struct vm_area_struct *vma, > unsigned long addr, pte_t *ptep) > { > @@ -1104,6 +1105,7 @@ static inline void set_huge_pte_at(struc > pte_t *ptep, pte_t pte) > { > } > +#endif > #endif /* CONFIG_HUGETLB_PAGE */ > > static inline spinlock_t *huge_pte_lock(struct hstate *h, > _