From mboxrd@z Thu Jan 1 00:00:00 1970 From: Baolin Wang Date: Wed, 11 May 2022 03:59:57 +0000 Subject: Re: [PATCH v3 2/3] mm: rmap: Fix CONT-PTE/PMD size hugetlb issue when migration Message-Id: <84209c7b-ac3e-fa3b-75fc-d76ec7c99d68@linux.alibaba.com> List-Id: References: <20220510161739.fdea4d78dde8471033aab22b@linux-foundation.org> <20220510162847.d9cf3c767e755a54699fb121@linux-foundation.org> In-Reply-To: <20220510162847.d9cf3c767e755a54699fb121@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit 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 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, > _