From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932471AbdIHSHz (ORCPT ); Fri, 8 Sep 2017 14:07:55 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:54086 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1756842AbdIHSHv (ORCPT ); Fri, 8 Sep 2017 14:07:51 -0400 From: Laurent Dufour To: paulmck@linux.vnet.ibm.com, peterz@infradead.org, akpm@linux-foundation.org, kirill@shutemov.name, ak@linux.intel.com, mhocko@kernel.org, dave@stgolabs.net, jack@suse.cz, Matthew Wilcox , benh@kernel.crashing.org, mpe@ellerman.id.au, paulus@samba.org, Thomas Gleixner , Ingo Molnar , hpa@zytor.com, Will Deacon , Sergey Senozhatsky Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, haren@linux.vnet.ibm.com, khandual@linux.vnet.ibm.com, npiggin@gmail.com, bsingharora@gmail.com, Tim Chen , linuxppc-dev@lists.ozlabs.org, x86@kernel.org Subject: [PATCH v3 11/20] mm: Introduce __maybe_mkwrite() Date: Fri, 8 Sep 2017 20:06:55 +0200 X-Mailer: git-send-email 2.7.4 In-Reply-To: <1504894024-2750-1-git-send-email-ldufour@linux.vnet.ibm.com> References: <1504894024-2750-1-git-send-email-ldufour@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 17090818-0040-0000-0000-000003F89DBE X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17090818-0041-0000-0000-00002099A53F Message-Id: <1504894024-2750-12-git-send-email-ldufour@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-09-08_12:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=2 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1707230000 definitions=main-1709080270 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The current maybe_mkwrite() is getting passed the pointer to the vma structure to fetch the vm_flags field. When dealing with the speculative page fault handler, it will be better to rely on the cached vm_flags value stored in the vm_fault structure. This patch introduce a __maybe_mkwrite() service which can be called by passing the value of the vm_flags field. There is no change functional changes expected for the other callers of maybe_mkwrite(). Signed-off-by: Laurent Dufour --- include/linux/mm.h | 9 +++++++-- mm/memory.c | 6 +++--- 2 files changed, 10 insertions(+), 5 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 5fd90ac31317..bb0c87f1c725 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -673,13 +673,18 @@ void free_compound_page(struct page *page); * pte_mkwrite. But get_user_pages can cause write faults for mappings * that do not have writing enabled, when used by access_process_vm. */ -static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma) +static inline pte_t __maybe_mkwrite(pte_t pte, unsigned long vma_flags) { - if (likely(vma->vm_flags & VM_WRITE)) + if (likely(vma_flags & VM_WRITE)) pte = pte_mkwrite(pte); return pte; } +static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma) +{ + return __maybe_mkwrite(pte, vma->vm_flags); +} + int alloc_set_pte(struct vm_fault *vmf, struct mem_cgroup *memcg, struct page *page); int finish_fault(struct vm_fault *vmf); diff --git a/mm/memory.c b/mm/memory.c index 4583f354be94..c306f1f64c9e 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2408,7 +2408,7 @@ static inline void wp_page_reuse(struct vm_fault *vmf) flush_cache_page(vma, vmf->address, pte_pfn(vmf->orig_pte)); entry = pte_mkyoung(vmf->orig_pte); - entry = maybe_mkwrite(pte_mkdirty(entry), vma); + entry = __maybe_mkwrite(pte_mkdirty(entry), vmf->vma_flags); if (ptep_set_access_flags(vma, vmf->address, vmf->pte, entry, 1)) update_mmu_cache(vma, vmf->address, vmf->pte); pte_unmap_unlock(vmf->pte, vmf->ptl); @@ -2498,8 +2498,8 @@ static int wp_page_copy(struct vm_fault *vmf) inc_mm_counter_fast(mm, MM_ANONPAGES); } flush_cache_page(vma, vmf->address, pte_pfn(vmf->orig_pte)); - entry = mk_pte(new_page, vma->vm_page_prot); - entry = maybe_mkwrite(pte_mkdirty(entry), vma); + entry = mk_pte(new_page, vmf->vma_page_prot); + entry = __maybe_mkwrite(pte_mkdirty(entry), vmf->vma_flags); /* * Clear the pte entry and flush it first, before updating the * pte with the new entry. This will avoid a race condition -- 2.7.4 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f197.google.com (mail-pf0-f197.google.com [209.85.192.197]) by kanga.kvack.org (Postfix) with ESMTP id 84F706B0375 for ; Fri, 8 Sep 2017 14:07:52 -0400 (EDT) Received: by mail-pf0-f197.google.com with SMTP id q75so5881073pfl.1 for ; Fri, 08 Sep 2017 11:07:52 -0700 (PDT) Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com. [148.163.156.1]) by mx.google.com with ESMTPS id z15si1926075pff.565.2017.09.08.11.07.51 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 08 Sep 2017 11:07:51 -0700 (PDT) Received: from pps.filterd (m0098399.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id v88I4S6r005479 for ; Fri, 8 Sep 2017 14:07:51 -0400 Received: from e06smtp11.uk.ibm.com (e06smtp11.uk.ibm.com [195.75.94.107]) by mx0a-001b2d01.pphosted.com with ESMTP id 2cuuw0dj7s-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Fri, 08 Sep 2017 14:07:50 -0400 Received: from localhost by e06smtp11.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 8 Sep 2017 19:07:48 +0100 From: Laurent Dufour Subject: [PATCH v3 11/20] mm: Introduce __maybe_mkwrite() Date: Fri, 8 Sep 2017 20:06:55 +0200 In-Reply-To: <1504894024-2750-1-git-send-email-ldufour@linux.vnet.ibm.com> References: <1504894024-2750-1-git-send-email-ldufour@linux.vnet.ibm.com> Message-Id: <1504894024-2750-12-git-send-email-ldufour@linux.vnet.ibm.com> Sender: owner-linux-mm@kvack.org List-ID: To: paulmck@linux.vnet.ibm.com, peterz@infradead.org, akpm@linux-foundation.org, kirill@shutemov.name, ak@linux.intel.com, mhocko@kernel.org, dave@stgolabs.net, jack@suse.cz, Matthew Wilcox , benh@kernel.crashing.org, mpe@ellerman.id.au, paulus@samba.org, Thomas Gleixner , Ingo Molnar , hpa@zytor.com, Will Deacon , Sergey Senozhatsky Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, haren@linux.vnet.ibm.com, khandual@linux.vnet.ibm.com, npiggin@gmail.com, bsingharora@gmail.com, Tim Chen , linuxppc-dev@lists.ozlabs.org, x86@kernel.org The current maybe_mkwrite() is getting passed the pointer to the vma structure to fetch the vm_flags field. When dealing with the speculative page fault handler, it will be better to rely on the cached vm_flags value stored in the vm_fault structure. This patch introduce a __maybe_mkwrite() service which can be called by passing the value of the vm_flags field. There is no change functional changes expected for the other callers of maybe_mkwrite(). Signed-off-by: Laurent Dufour --- include/linux/mm.h | 9 +++++++-- mm/memory.c | 6 +++--- 2 files changed, 10 insertions(+), 5 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 5fd90ac31317..bb0c87f1c725 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -673,13 +673,18 @@ void free_compound_page(struct page *page); * pte_mkwrite. But get_user_pages can cause write faults for mappings * that do not have writing enabled, when used by access_process_vm. */ -static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma) +static inline pte_t __maybe_mkwrite(pte_t pte, unsigned long vma_flags) { - if (likely(vma->vm_flags & VM_WRITE)) + if (likely(vma_flags & VM_WRITE)) pte = pte_mkwrite(pte); return pte; } +static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma) +{ + return __maybe_mkwrite(pte, vma->vm_flags); +} + int alloc_set_pte(struct vm_fault *vmf, struct mem_cgroup *memcg, struct page *page); int finish_fault(struct vm_fault *vmf); diff --git a/mm/memory.c b/mm/memory.c index 4583f354be94..c306f1f64c9e 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2408,7 +2408,7 @@ static inline void wp_page_reuse(struct vm_fault *vmf) flush_cache_page(vma, vmf->address, pte_pfn(vmf->orig_pte)); entry = pte_mkyoung(vmf->orig_pte); - entry = maybe_mkwrite(pte_mkdirty(entry), vma); + entry = __maybe_mkwrite(pte_mkdirty(entry), vmf->vma_flags); if (ptep_set_access_flags(vma, vmf->address, vmf->pte, entry, 1)) update_mmu_cache(vma, vmf->address, vmf->pte); pte_unmap_unlock(vmf->pte, vmf->ptl); @@ -2498,8 +2498,8 @@ static int wp_page_copy(struct vm_fault *vmf) inc_mm_counter_fast(mm, MM_ANONPAGES); } flush_cache_page(vma, vmf->address, pte_pfn(vmf->orig_pte)); - entry = mk_pte(new_page, vma->vm_page_prot); - entry = maybe_mkwrite(pte_mkdirty(entry), vma); + entry = mk_pte(new_page, vmf->vma_page_prot); + entry = __maybe_mkwrite(pte_mkdirty(entry), vmf->vma_flags); /* * Clear the pte entry and flush it first, before updating the * pte with the new entry. This will avoid a race condition -- 2.7.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org