{"id":811784,"url":"http://patchwork.ozlabs.org/api/1.2/patches/811784/?format=json","web_url":"http://patchwork.ozlabs.org/project/linuxppc-dev/patch/1504894024-2750-5-git-send-email-ldufour@linux.vnet.ibm.com/","project":{"id":2,"url":"http://patchwork.ozlabs.org/api/1.2/projects/2/?format=json","name":"Linux PPC development","link_name":"linuxppc-dev","list_id":"linuxppc-dev.lists.ozlabs.org","list_email":"linuxppc-dev@lists.ozlabs.org","web_url":"https://github.com/linuxppc/wiki/wiki","scm_url":"https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git","webscm_url":"https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/","list_archive_url":"https://lore.kernel.org/linuxppc-dev/","list_archive_url_format":"https://lore.kernel.org/linuxppc-dev/{}/","commit_url_format":"https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/commit/?id={}"},"msgid":"<1504894024-2750-5-git-send-email-ldufour@linux.vnet.ibm.com>","list_archive_url":"https://lore.kernel.org/linuxppc-dev/1504894024-2750-5-git-send-email-ldufour@linux.vnet.ibm.com/","date":"2017-09-08T18:06:48","name":"[v3,04/20] mm: VMA sequence count","commit_ref":null,"pull_url":null,"state":"not-applicable","archived":false,"hash":"fe34f49b0d85c1fbb1337f38dd122d02841d822a","submitter":{"id":40248,"url":"http://patchwork.ozlabs.org/api/1.2/people/40248/?format=json","name":"Laurent Dufour","email":"ldufour@linux.vnet.ibm.com"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/linuxppc-dev/patch/1504894024-2750-5-git-send-email-ldufour@linux.vnet.ibm.com/mbox/","series":[{"id":2269,"url":"http://patchwork.ozlabs.org/api/1.2/series/2269/?format=json","web_url":"http://patchwork.ozlabs.org/project/linuxppc-dev/list/?series=2269","date":"2017-09-08T18:06:44","name":"Speculative page faults","version":3,"mbox":"http://patchwork.ozlabs.org/series/2269/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/811784/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/811784/checks/","tags":{},"related":[],"headers":{"Return-Path":"","X-Original-To":["patchwork-incoming@ozlabs.org","linuxppc-dev@lists.ozlabs.org"],"Delivered-To":["patchwork-incoming@ozlabs.org","linuxppc-dev@lists.ozlabs.org"],"Received":["from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3])\n\t(using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits))\n\t(No client certificate requested)\n\tby ozlabs.org (Postfix) with ESMTPS id 3xplyB5XZTz9s7C\n\tfor ;\n\tSat, 9 Sep 2017 04:21:22 +1000 (AEST)","from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3])\n\tby lists.ozlabs.org (Postfix) with ESMTP id 3xplyB3yGwzDqF4\n\tfor ;\n\tSat, 9 Sep 2017 04:21:22 +1000 (AEST)","from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com\n\t[148.163.158.5])\n\t(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256\n\tbits)) (No client certificate requested)\n\tby lists.ozlabs.org (Postfix) with ESMTPS id 3xplfC61tnzDrZW\n\tfor ;\n\tSat, 9 Sep 2017 04:07:31 +1000 (AEST)","from pps.filterd (m0098419.ppops.net [127.0.0.1])\n\tby mx0b-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id\n\tv88I4RZt021350\n\tfor ; Fri, 8 Sep 2017 14:07:29 -0400","from e06smtp15.uk.ibm.com (e06smtp15.uk.ibm.com [195.75.94.111])\n\tby mx0b-001b2d01.pphosted.com with ESMTP id 2cuuu8x6x2-1\n\t(version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT)\n\tfor ; Fri, 08 Sep 2017 14:07:28 -0400","from localhost\n\tby e06smtp15.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use\n\tOnly! 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Violators will be prosecuted; \n\tFri, 8 Sep 2017 19:07:20 +0100","from d06av24.portsmouth.uk.ibm.com (d06av24.portsmouth.uk.ibm.com\n\t[9.149.105.60])\n\tby b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with\n\tESMTP id v88I7JXd25100314; Fri, 8 Sep 2017 18:07:19 GMT","from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1])\n\tby IMSVA (Postfix) with ESMTP id B185D42041;\n\tFri, 8 Sep 2017 19:03:46 +0100 (BST)","from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1])\n\tby IMSVA (Postfix) with ESMTP id DDFE84203F;\n\tFri, 8 Sep 2017 19:03:44 +0100 (BST)","from nimbus.lab.toulouse-stg.fr.ibm.com (unknown [9.145.31.125])\n\tby d06av24.portsmouth.uk.ibm.com (Postfix) with ESMTP;\n\tFri, 8 Sep 2017 19:03:44 +0100 (BST)"],"Authentication-Results":"ozlabs.org;\n\tspf=none (mailfrom) smtp.mailfrom=linux.vnet.ibm.com\n\t(client-ip=148.163.158.5; helo=mx0a-001b2d01.pphosted.com;\n\tenvelope-from=ldufour@linux.vnet.ibm.com; receiver=)","From":"Laurent Dufour ","To":"paulmck@linux.vnet.ibm.com, peterz@infradead.org,\n\takpm@linux-foundation.org, kirill@shutemov.name, ak@linux.intel.com, \n\tmhocko@kernel.org, dave@stgolabs.net, jack@suse.cz,\n\tMatthew Wilcox , benh@kernel.crashing.org,\n\tmpe@ellerman.id.au, paulus@samba.org,\n\tThomas Gleixner , Ingo Molnar , \n\thpa@zytor.com, Will Deacon ,\n\tSergey Senozhatsky ","Subject":"[PATCH v3 04/20] mm: VMA sequence count","Date":"Fri, 8 Sep 2017 20:06:48 +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":"17090818-0020-0000-0000-000003B69F38","X-IBM-AV-DETECTION":"SAVI=unused REMOTE=unused XFE=unused","x-cbparentid":"17090818-0021-0000-0000-00004247AAA1","Message-Id":"<1504894024-2750-5-git-send-email-ldufour@linux.vnet.ibm.com>","X-Proofpoint-Virus-Version":"vendor=fsecure engine=2.50.10432:, ,\n\tdefinitions=2017-09-08_12:, , signatures=0","X-Proofpoint-Spam-Details":"rule=outbound_notspam policy=outbound score=0\n\tspamscore=0 suspectscore=2\n\tmalwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam\n\tadjust=0 reason=mlx scancount=1 engine=8.0.1-1707230000\n\tdefinitions=main-1709080270","X-BeenThere":"linuxppc-dev@lists.ozlabs.org","X-Mailman-Version":"2.1.23","Precedence":"list","List-Id":"Linux on PowerPC Developers Mail List\n\t","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Cc":"linuxppc-dev@lists.ozlabs.org, x86@kernel.org,\n\tlinux-kernel@vger.kernel.org, npiggin@gmail.com, linux-mm@kvack.org,\n\tTim Chen , \n\tharen@linux.vnet.ibm.com, khandual@linux.vnet.ibm.com","Errors-To":"linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org","Sender":"\"Linuxppc-dev\"\n\t"},"content":"From: Peter Zijlstra \n\nWrap the VMA modifications (vma_adjust/unmap_page_range) with sequence\ncounts such that we can easily test if a VMA is changed.\n\nThe unmap_page_range() one allows us to make assumptions about\npage-tables; when we find the seqcount hasn't changed we can assume\npage-tables are still valid.\n\nThe flip side is that we cannot distinguish between a vma_adjust() and\nthe unmap_page_range() -- where with the former we could have\nre-checked the vma bounds against the address.\n\nSigned-off-by: Peter Zijlstra (Intel) \n\n[Port to 4.12 kernel]\n[Fix lock dependency between mapping->i_mmap_rwsem and vma->vm_sequence]\nSigned-off-by: Laurent Dufour \n---\n include/linux/mm_types.h | 1 +\n mm/memory.c | 2 ++\n mm/mmap.c | 21 ++++++++++++++++++---\n 3 files changed, 21 insertions(+), 3 deletions(-)","diff":"diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h\nindex 46f4ecf5479a..df9a530c8ca1 100644\n--- a/include/linux/mm_types.h\n+++ b/include/linux/mm_types.h\n@@ -344,6 +344,7 @@ struct vm_area_struct {\n \tstruct mempolicy *vm_policy;\t/* NUMA policy for the VMA */\n #endif\n \tstruct vm_userfaultfd_ctx vm_userfaultfd_ctx;\n+\tseqcount_t vm_sequence;\n } __randomize_layout;\n \n struct core_thread {\ndiff --git a/mm/memory.c b/mm/memory.c\nindex 530d887ca885..f250e7c92948 100644\n--- a/mm/memory.c\n+++ b/mm/memory.c\n@@ -1499,6 +1499,7 @@ void unmap_page_range(struct mmu_gather *tlb,\n \tunsigned long next;\n \n \tBUG_ON(addr >= end);\n+\twrite_seqcount_begin(&vma->vm_sequence);\n \ttlb_start_vma(tlb, vma);\n \tpgd = pgd_offset(vma->vm_mm, addr);\n \tdo {\n@@ -1508,6 +1509,7 @@ void unmap_page_range(struct mmu_gather *tlb,\n \t\tnext = zap_p4d_range(tlb, vma, pgd, addr, next, details);\n \t} while (pgd++, addr = next, addr != end);\n \ttlb_end_vma(tlb, vma);\n+\twrite_seqcount_end(&vma->vm_sequence);\n }\n \n \ndiff --git a/mm/mmap.c b/mm/mmap.c\nindex 680506faceae..0a0012c7e50c 100644\n--- a/mm/mmap.c\n+++ b/mm/mmap.c\n@@ -558,6 +558,8 @@ void __vma_link_rb(struct mm_struct *mm, struct vm_area_struct *vma,\n \telse\n \t\tmm->highest_vm_end = vm_end_gap(vma);\n \n+\tseqcount_init(&vma->vm_sequence);\n+\n \t/*\n \t * vma->vm_prev wasn't known when we followed the rbtree to find the\n \t * correct insertion point for that vma. As a result, we could not\n@@ -799,6 +801,11 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start,\n \t\t}\n \t}\n \n+\twrite_seqcount_begin(&vma->vm_sequence);\n+\tif (next && next != vma)\n+\t\twrite_seqcount_begin_nested(&next->vm_sequence,\n+\t\t\t\t\t SINGLE_DEPTH_NESTING);\n+\n \tanon_vma = vma->anon_vma;\n \tif (!anon_vma && adjust_next)\n \t\tanon_vma = next->anon_vma;\n@@ -903,6 +910,7 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start,\n \t\tmm->map_count--;\n \t\tmpol_put(vma_policy(next));\n \t\tkmem_cache_free(vm_area_cachep, next);\n+\t\twrite_seqcount_end(&next->vm_sequence);\n \t\t/*\n \t\t * In mprotect's case 6 (see comments on vma_merge),\n \t\t * we must remove another next too. It would clutter\n@@ -932,11 +940,14 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start,\n \t\tif (remove_next == 2) {\n \t\t\tremove_next = 1;\n \t\t\tend = next->vm_end;\n+\t\t\twrite_seqcount_end(&vma->vm_sequence);\n \t\t\tgoto again;\n-\t\t}\n-\t\telse if (next)\n+\t\t} else if (next) {\n+\t\t\tif (next != vma)\n+\t\t\t\twrite_seqcount_begin_nested(&next->vm_sequence,\n+\t\t\t\t\t\t\t SINGLE_DEPTH_NESTING);\n \t\t\tvma_gap_update(next);\n-\t\telse {\n+\t\t} else {\n \t\t\t/*\n \t\t\t * If remove_next == 2 we obviously can't\n \t\t\t * reach this path.\n@@ -962,6 +973,10 @@ int __vma_adjust(struct vm_area_struct *vma, unsigned long start,\n \tif (insert && file)\n \t\tuprobe_mmap(insert);\n \n+\tif (next && next != vma)\n+\t\twrite_seqcount_end(&next->vm_sequence);\n+\twrite_seqcount_end(&vma->vm_sequence);\n+\n \tvalidate_mm(mm);\n \n \treturn 0;\n","prefixes":["v3","04/20"]}