{"id":811807,"url":"http://patchwork.ozlabs.org/api/1.2/patches/811807/?format=json","web_url":"http://patchwork.ozlabs.org/project/linuxppc-dev/patch/1504894024-2750-20-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":"<1504894024-2750-20-git-send-email-ldufour@linux.vnet.ibm.com>","list_archive_url":"https://lore.kernel.org/linuxppc-dev/1504894024-2750-20-git-send-email-ldufour@linux.vnet.ibm.com/","date":"2017-09-08T18:07:03","name":"[v3,19/20] x86/mm: Add speculative pagefault handling","commit_ref":null,"pull_url":null,"state":"not-applicable","archived":false,"hash":"357f4295b53dbac89ada674081843db6b38fe51c","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/1504894024-2750-20-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/811807/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/811807/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 3xpmw41CbRz9sRV\n\tfor ;\n\tSat, 9 Sep 2017 05:04:36 +1000 (AEST)","from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3])\n\tby lists.ozlabs.org (Postfix) with ESMTP id 3xpmw36HXlzDrcN\n\tfor ;\n\tSat, 9 Sep 2017 05:04:35 +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 3xplgF5F42zDrYd\n\tfor ;\n\tSat, 9 Sep 2017 04:08:25 +1000 (AEST)","from pps.filterd (m0098413.ppops.net [127.0.0.1])\n\tby mx0b-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id\n\tv88I4YgL056603\n\tfor ; Fri, 8 Sep 2017 14:08:23 -0400","from e06smtp13.uk.ibm.com (e06smtp13.uk.ibm.com [195.75.94.109])\n\tby mx0b-001b2d01.pphosted.com with ESMTP id 2cuw4n1be6-1\n\t(version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT)\n\tfor ; Fri, 08 Sep 2017 14:08:23 -0400","from localhost\n\tby e06smtp13.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 19:08:15 +0100","from d06av24.portsmouth.uk.ibm.com (mk.ibm.com [9.149.105.60])\n\tby b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with\n\tESMTP id v88I8Ep830736418; Fri, 8 Sep 2017 18:08:14 GMT","from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1])\n\tby IMSVA (Postfix) with ESMTP id D878F42042;\n\tFri, 8 Sep 2017 19:04:41 +0100 (BST)","from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1])\n\tby IMSVA (Postfix) with ESMTP id 264844203F;\n\tFri, 8 Sep 2017 19:04:40 +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 19:04:40 +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 19/20] x86/mm: Add speculative pagefault handling","Date":"Fri, 8 Sep 2017 20:07:03 +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":"17090818-0012-0000-0000-00000577A9B2","X-IBM-AV-DETECTION":"SAVI=unused REMOTE=unused XFE=unused","x-cbparentid":"17090818-0013-0000-0000-000018F0B12E","Message-Id":"<1504894024-2750-20-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":"From: Peter Zijlstra \n\nTry a speculative fault before acquiring mmap_sem, if it returns with\nVM_FAULT_RETRY continue with the mmap_sem acquisition and do the\ntraditional fault.\n\nSigned-off-by: Peter Zijlstra (Intel) \n\n[Clearing of FAULT_FLAG_ALLOW_RETRY is now done in\n handle_speculative_fault()]\n[Retry with usual fault path in the case VM_ERROR is returned by\n handle_speculative_fault(). This allows signal to be delivered]\nSigned-off-by: Laurent Dufour \n---\n arch/x86/include/asm/pgtable_types.h | 7 +++++++\n arch/x86/mm/fault.c | 19 +++++++++++++++++++\n 2 files changed, 26 insertions(+)","diff":"diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h\nindex f1492473f10e..aadc8ecb91fb 100644\n--- a/arch/x86/include/asm/pgtable_types.h\n+++ b/arch/x86/include/asm/pgtable_types.h\n@@ -257,6 +257,13 @@ enum page_cache_mode {\n #define PGD_IDENT_ATTR\t 0x001\t\t/* PRESENT (no other attributes) */\n #endif\n \n+/*\n+ * Advertise that we call the Speculative Page Fault handler.\n+ */\n+#ifdef CONFIG_X86_64\n+#define __HAVE_ARCH_CALL_SPF\n+#endif\n+\n #ifdef CONFIG_X86_32\n # include \n #else\ndiff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c\nindex b836a7274e12..652af5524f42 100644\n--- a/arch/x86/mm/fault.c\n+++ b/arch/x86/mm/fault.c\n@@ -1365,6 +1365,24 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code,\n \tif (error_code & PF_INSTR)\n \t\tflags |= FAULT_FLAG_INSTRUCTION;\n \n+#ifdef __HAVE_ARCH_CALL_SPF\n+\tif (error_code & PF_USER) {\n+\t\tfault = handle_speculative_fault(mm, address, flags);\n+\n+\t\t/*\n+\t\t * We also check against VM_FAULT_ERROR because we have to\n+\t\t * raise a signal by calling later mm_fault_error() which\n+\t\t * requires the vma pointer to be set. So in that case,\n+\t\t * we fall through the normal path.\n+\t\t */\n+\t\tif (!(fault & VM_FAULT_RETRY || fault & VM_FAULT_ERROR)) {\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 /* __HAVE_ARCH_CALL_SPF */\n+\n \t/*\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\n@@ -1474,6 +1492,7 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code,\n \t\treturn;\n \t}\n \n+done:\n \t/*\n \t * Major/minor page fault accounting. If any of the events\n \t * returned VM_FAULT_MAJOR, we account it as a major fault.\n","prefixes":["v3","19/20"]}