{"id":811811,"url":"http://patchwork.ozlabs.org/api/1.2/patches/811811/?format=json","web_url":"http://patchwork.ozlabs.org/project/linuxppc-dev/patch/1504894024-2750-21-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":"<1504894024-2750-21-git-send-email-ldufour@linux.vnet.ibm.com>","list_archive_url":"https://lore.kernel.org/linuxppc-dev/1504894024-2750-21-git-send-email-ldufour@linux.vnet.ibm.com/","date":"2017-09-08T18:07:04","name":"[v3,20/20] powerpc/mm: Add speculative page fault","commit_ref":null,"pull_url":null,"state":"not-applicable","archived":false,"hash":"498a12d56a3a1f1622de2788d93fb48a41113147","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/1504894024-2750-21-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/811811/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/811811/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 [103.22.144.68])\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 3xpn7h29vqz9sRV\n\tfor ;\n\tSat, 9 Sep 2017 05:14:40 +1000 (AEST)","from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3])\n\tby lists.ozlabs.org (Postfix) with ESMTP id 3xpn7g4Db3zDqYN\n\tfor ;\n\tSat, 9 Sep 2017 05:14:39 +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 3xplgL5qW5zDrZW\n\tfor ;\n\tSat, 9 Sep 2017 04:08:30 +1000 (AEST)","from pps.filterd (m0098416.ppops.net [127.0.0.1])\n\tby mx0b-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id\n\tv88I4SJN043914\n\tfor ; Fri, 8 Sep 2017 14:08:26 -0400","from e06smtp15.uk.ibm.com (e06smtp15.uk.ibm.com [195.75.94.111])\n\tby mx0b-001b2d01.pphosted.com with ESMTP id 2cuw50sfh1-1\n\t(version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT)\n\tfor ; Fri, 08 Sep 2017 14:08:26 -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 19:08:18 +0100","from d06av24.portsmouth.uk.ibm.com (d06av24.portsmouth.uk.ibm.com\n\t[9.149.105.60])\n\tby b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with\n\tESMTP id v88I8Hft11796658; Fri, 8 Sep 2017 18:08:17 GMT","from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1])\n\tby IMSVA (Postfix) with ESMTP id B131E42041;\n\tFri, 8 Sep 2017 19:04:44 +0100 (BST)","from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1])\n\tby IMSVA (Postfix) with ESMTP id 0132A4203F;\n\tFri, 8 Sep 2017 19:04:43 +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 19:04:42 +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 20/20] powerpc/mm: Add speculative page fault","Date":"Fri, 8 Sep 2017 20:07:04 +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":"17090818-0020-0000-0000-000003B69F52","X-IBM-AV-DETECTION":"SAVI=unused REMOTE=unused XFE=unused","x-cbparentid":"17090818-0021-0000-0000-00004247AABF","Message-Id":"<1504894024-2750-21-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=0\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":"This patch enable the speculative page fault on the PowerPC\narchitecture.\n\nThis will try a speculative page fault without holding the mmap_sem,\nif it returns with VM_FAULT_RETRY, the mmap_sem is acquired and the\ntraditional page fault processing is done.\n\nSupport is only provide for BOOK3S_64 currently because:\n- require CONFIG_PPC_STD_MMU because checks done in\n set_access_flags_filter()\n- require BOOK3S because we can't support for book3e_hugetlb_preload()\n called by update_mmu_cache()\n\nSigned-off-by: Laurent Dufour \n---\n arch/powerpc/include/asm/book3s/64/pgtable.h | 5 +++++\n arch/powerpc/mm/fault.c | 15 +++++++++++++++\n 2 files changed, 20 insertions(+)","diff":"diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h\nindex b9aff515b4de..470203daf97e 100644\n--- a/arch/powerpc/include/asm/book3s/64/pgtable.h\n+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h\n@@ -314,6 +314,11 @@ extern unsigned long pci_io_base;\n /* Advertise support for _PAGE_SPECIAL */\n #define __HAVE_ARCH_PTE_SPECIAL\n \n+/* Advertise that we call the Speculative Page Fault handler */\n+#if defined(CONFIG_PPC_BOOK3S_64)\n+#define __HAVE_ARCH_CALL_SPF\n+#endif\n+\n #ifndef __ASSEMBLY__\n \n /*\ndiff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c\nindex 4797d08581ce..97c7de242627 100644\n--- a/arch/powerpc/mm/fault.c\n+++ b/arch/powerpc/mm/fault.c\n@@ -442,6 +442,20 @@ static int __do_page_fault(struct pt_regs *regs, unsigned long address,\n \tif (is_exec)\n \t\tflags |= FAULT_FLAG_INSTRUCTION;\n \n+#if defined(__HAVE_ARCH_CALL_SPF)\n+\tif (is_user) {\n+\t\t/* let's try a speculative page fault without grabbing the\n+\t\t * mmap_sem.\n+\t\t */\n+\t\tfault = handle_speculative_fault(mm, address, flags);\n+\t\tif (!(fault & VM_FAULT_RETRY)) {\n+\t\t\tperf_sw_event(PERF_COUNT_SW_SPF, 1,\n+\t\t\t\t regs, address);\n+\t\t\tgoto done;\n+\t\t}\n+\t}\n+#endif /* defined(__HAVE_ARCH_CALL_SPF) */\n+\n \t/* When running in the kernel we expect faults to occur only to\n \t * addresses in user space. All other faults represent errors in the\n \t * kernel and should generate an OOPS. Unfortunately, in the case of an\n@@ -526,6 +540,7 @@ static int __do_page_fault(struct pt_regs *regs, unsigned long address,\n \n \tup_read(¤t->mm->mmap_sem);\n \n+done:\n \tif (unlikely(fault & VM_FAULT_ERROR))\n \t\treturn mm_fault_error(regs, address, fault);\n \n","prefixes":["v3","20/20"]}