From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932549AbaICV20 (ORCPT ); Wed, 3 Sep 2014 17:28:26 -0400 Received: from mail-pa0-f52.google.com ([209.85.220.52]:63195 "EHLO mail-pa0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932130AbaICV2Y (ORCPT ); Wed, 3 Sep 2014 17:28:24 -0400 Date: Wed, 3 Sep 2014 14:26:37 -0700 (PDT) From: Hugh Dickins X-X-Sender: hugh@eggly.anvils To: Naoya Horiguchi cc: Andrew Morton , Hugh Dickins , David Rientjes , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Naoya Horiguchi Subject: Re: [PATCH v3 6/6] mm/hugetlb: remove unused argument of follow_huge_addr() In-Reply-To: <1409276340-7054-7-git-send-email-n-horiguchi@ah.jp.nec.com> Message-ID: References: <1409276340-7054-1-git-send-email-n-horiguchi@ah.jp.nec.com> <1409276340-7054-7-git-send-email-n-horiguchi@ah.jp.nec.com> User-Agent: Alpine 2.11 (LSU 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 28 Aug 2014, Naoya Horiguchi wrote: > follow_huge_addr()'s parameter write is not used, so let's remove it. > > Signed-off-by: Naoya Horiguchi I think this patch is a waste of time: that it should be replaced by a patch which replaces the "write" argument by a "flags" argument, so that follow_huge_addr() can do get_page() for FOLL_GET while holding appropriate lock, instead of the BUG_ON(flags & FOLL_GET) we currently have. Once that is implemented, you could try getting hugetlb migration tested on ia64 and powerpc; but yes, keep hugetlb migration disabled on all but x86 until it has been tested elsewhere. > --- > arch/ia64/mm/hugetlbpage.c | 2 +- > arch/powerpc/mm/hugetlbpage.c | 2 +- > arch/x86/mm/hugetlbpage.c | 2 +- > include/linux/hugetlb.h | 5 ++--- > mm/gup.c | 2 +- > mm/hugetlb.c | 3 +-- > 6 files changed, 7 insertions(+), 9 deletions(-) > > diff --git mmotm-2014-08-25-16-52.orig/arch/ia64/mm/hugetlbpage.c mmotm-2014-08-25-16-52/arch/ia64/mm/hugetlbpage.c > index 6170381bf074..524a4e001bda 100644 > --- mmotm-2014-08-25-16-52.orig/arch/ia64/mm/hugetlbpage.c > +++ mmotm-2014-08-25-16-52/arch/ia64/mm/hugetlbpage.c > @@ -89,7 +89,7 @@ int prepare_hugepage_range(struct file *file, > return 0; > } > > -struct page *follow_huge_addr(struct mm_struct *mm, unsigned long addr, int write) > +struct page *follow_huge_addr(struct mm_struct *mm, unsigned long addr) > { > struct page *page = NULL; > pte_t *ptep; > diff --git mmotm-2014-08-25-16-52.orig/arch/powerpc/mm/hugetlbpage.c mmotm-2014-08-25-16-52/arch/powerpc/mm/hugetlbpage.c > index 1d8854a56309..5b6fe8b0cde3 100644 > --- mmotm-2014-08-25-16-52.orig/arch/powerpc/mm/hugetlbpage.c > +++ mmotm-2014-08-25-16-52/arch/powerpc/mm/hugetlbpage.c > @@ -674,7 +674,7 @@ void hugetlb_free_pgd_range(struct mmu_gather *tlb, > } > > struct page * > -follow_huge_addr(struct mm_struct *mm, unsigned long address, int write) > +follow_huge_addr(struct mm_struct *mm, unsigned long address) > { > pte_t *ptep; > struct page *page = ERR_PTR(-EINVAL); > diff --git mmotm-2014-08-25-16-52.orig/arch/x86/mm/hugetlbpage.c mmotm-2014-08-25-16-52/arch/x86/mm/hugetlbpage.c > index 03b8a7c11817..cab09d87ae65 100644 > --- mmotm-2014-08-25-16-52.orig/arch/x86/mm/hugetlbpage.c > +++ mmotm-2014-08-25-16-52/arch/x86/mm/hugetlbpage.c > @@ -18,7 +18,7 @@ > > #if 0 /* This is just for testing */ > struct page * > -follow_huge_addr(struct mm_struct *mm, unsigned long address, int write) > +follow_huge_addr(struct mm_struct *mm, unsigned long address) > { > unsigned long start = address; > int length = 1; > diff --git mmotm-2014-08-25-16-52.orig/include/linux/hugetlb.h mmotm-2014-08-25-16-52/include/linux/hugetlb.h > index b3200fce07aa..cdff1bd393bb 100644 > --- mmotm-2014-08-25-16-52.orig/include/linux/hugetlb.h > +++ mmotm-2014-08-25-16-52/include/linux/hugetlb.h > @@ -96,8 +96,7 @@ pte_t *huge_pte_alloc(struct mm_struct *mm, > unsigned long addr, unsigned long sz); > pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr); > int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep); > -struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address, > - int write); > +struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address); > struct page *follow_huge_pmd(struct vm_area_struct *vma, unsigned long address, > pmd_t *pmd, int flags); > struct page *follow_huge_pud(struct vm_area_struct *vma, unsigned long address, > @@ -124,7 +123,7 @@ static inline unsigned long hugetlb_total_pages(void) > } > > #define follow_hugetlb_page(m,v,p,vs,a,b,i,w) ({ BUG(); 0; }) > -#define follow_huge_addr(mm, addr, write) ERR_PTR(-EINVAL) > +#define follow_huge_addr(mm, addr) ERR_PTR(-EINVAL) > #define copy_hugetlb_page_range(src, dst, vma) ({ BUG(); 0; }) > static inline void hugetlb_report_meminfo(struct seq_file *m) > { > diff --git mmotm-2014-08-25-16-52.orig/mm/gup.c mmotm-2014-08-25-16-52/mm/gup.c > index 597a5e92e265..8f0550f1770d 100644 > --- mmotm-2014-08-25-16-52.orig/mm/gup.c > +++ mmotm-2014-08-25-16-52/mm/gup.c > @@ -149,7 +149,7 @@ struct page *follow_page_mask(struct vm_area_struct *vma, > > *page_mask = 0; > > - page = follow_huge_addr(mm, address, flags & FOLL_WRITE); > + page = follow_huge_addr(mm, address); > if (!IS_ERR(page)) { > BUG_ON(flags & FOLL_GET); > return page; > diff --git mmotm-2014-08-25-16-52.orig/mm/hugetlb.c mmotm-2014-08-25-16-52/mm/hugetlb.c > index 0a4511115ee0..f7dcad3474ec 100644 > --- mmotm-2014-08-25-16-52.orig/mm/hugetlb.c > +++ mmotm-2014-08-25-16-52/mm/hugetlb.c > @@ -3690,8 +3690,7 @@ pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr) > * behavior. > */ > struct page * __weak > -follow_huge_addr(struct mm_struct *mm, unsigned long address, > - int write) > +follow_huge_addr(struct mm_struct *mm, unsigned long address) > { > return ERR_PTR(-EINVAL); > } > -- > 1.9.3