From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757430AbeD0FtN (ORCPT ); Fri, 27 Apr 2018 01:49:13 -0400 Received: from mail-lf0-f66.google.com ([209.85.215.66]:43609 "EHLO mail-lf0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751458AbeD0FtL (ORCPT ); Fri, 27 Apr 2018 01:49:11 -0400 X-Google-Smtp-Source: AB8JxZpjECgmt36O2FlLvF9EmM0pczGqgLPiXycvwD4/k1QYDmGAcspLS7/jekJW34i3G8YMKDCsaQE3zzaZH7XBn90= MIME-Version: 1.0 In-Reply-To: References: <20180425044326.GA21504@jordon-HP-15-Notebook-PC> From: Souptick Joarder Date: Fri, 27 Apr 2018 11:19:09 +0530 Message-ID: Subject: Re: [PATCH v2] mm: huge_memory: Change return type to vm_fault_t To: David Rientjes , Matthew Wilcox Cc: Andrew Morton , zi.yan@cs.rutgers.edu, Dan Williams , kirill.shutemov@linux.intel.com, Ross Zwisler , n-horiguchi@ah.jp.nec.com, Michal Hocko , shli@fb.com, linux-kernel@vger.kernel.org, Linux-MM Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 25, 2018 at 12:39 PM, David Rientjes wrote: > On Wed, 25 Apr 2018, Souptick Joarder wrote: > >> Use new return type vm_fault_t for fault handler. For >> now, this is just documenting that the function returns >> a VM_FAULT value rather than an errno. Once all instances >> are converted, vm_fault_t will become a distinct type. >> >> Commit 1c8f422059ae ("mm: change return type to vm_fault_t") >> >> Signed-off-by: Souptick Joarder >> Reviewed-by: Matthew Wilcox >> --- >> v2: Updated the change log >> >> include/linux/huge_mm.h | 5 +++-- >> mm/huge_memory.c | 4 ++-- >> 2 files changed, 5 insertions(+), 4 deletions(-) >> >> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h >> index a8a1262..d3bbf6b 100644 >> --- a/include/linux/huge_mm.h >> +++ b/include/linux/huge_mm.h >> @@ -3,6 +3,7 @@ >> #define _LINUX_HUGE_MM_H >> >> #include >> +#include >> >> #include /* only for vma_is_dax() */ >> >> @@ -46,9 +47,9 @@ extern bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr, >> extern int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, >> unsigned long addr, pgprot_t newprot, >> int prot_numa); >> -int vmf_insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, >> +vm_fault_t vmf_insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, >> pmd_t *pmd, pfn_t pfn, bool write); >> -int vmf_insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr, >> +vm_fault_t vmf_insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr, >> pud_t *pud, pfn_t pfn, bool write); >> enum transparent_hugepage_flag { >> TRANSPARENT_HUGEPAGE_FLAG, >> diff --git a/mm/huge_memory.c b/mm/huge_memory.c >> index 87ab9b8..1fe4705 100644 >> --- a/mm/huge_memory.c >> +++ b/mm/huge_memory.c >> @@ -755,7 +755,7 @@ static void insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, >> spin_unlock(ptl); >> } >> >> -int vmf_insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, >> +vm_fault_t vmf_insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, >> pmd_t *pmd, pfn_t pfn, bool write) >> { >> pgprot_t pgprot = vma->vm_page_prot; >> @@ -815,7 +815,7 @@ static void insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr, >> spin_unlock(ptl); >> } >> >> -int vmf_insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr, >> +vm_fault_t vmf_insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr, >> pud_t *pud, pfn_t pfn, bool write) >> { >> pgprot_t pgprot = vma->vm_page_prot; > > This isn't very useful unless functions that return the return value of > these functions, __dev_dax_{pmd,pud}_fault(), recast it as an int. > __dev_dax_pte_fault() would do the same thing, so it should logically also > be vm_fault_t, so then you would convert dev_dax_huge_fault() and > dev_dax_fault() as well in the same patch. yes, the return value of _dev_dax_{pmd,pud,pte}_fault(), dev_dax_huge_fault(), dev_dax_fault() is already changed in a separate patch which was reviewed by Matthew and Ross. Other patch was posted in linux-nvdimm mailing list.