From patchwork Mon Oct 9 10:07:51 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Laurent Dufour X-Patchwork-Id: 823187 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [103.22.144.68]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3y9cCP5h14z9tXx for ; Mon, 9 Oct 2017 21:38:09 +1100 (AEDT) Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 3y9cCP4sXTzDrqS for ; Mon, 9 Oct 2017 21:38:09 +1100 (AEDT) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=linux.vnet.ibm.com (client-ip=148.163.158.5; helo=mx0a-001b2d01.pphosted.com; envelope-from=ldufour@linux.vnet.ibm.com; receiver=) Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3y9bYv3SPszDr55 for ; Mon, 9 Oct 2017 21:09:07 +1100 (AEDT) Received: from pps.filterd (m0098419.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id v99A8ejD025090 for ; Mon, 9 Oct 2017 06:09:04 -0400 Received: from e06smtp15.uk.ibm.com (e06smtp15.uk.ibm.com [195.75.94.111]) by mx0b-001b2d01.pphosted.com with ESMTP id 2dg4cp72yx-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Mon, 09 Oct 2017 06:09:04 -0400 Received: from localhost by e06smtp15.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Mon, 9 Oct 2017 11:08:56 +0100 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06cxnps4075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v99A8uhr14876802; Mon, 9 Oct 2017 10:08:56 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 5F2C352041; Mon, 9 Oct 2017 10:03:28 +0100 (BST) Received: from nimbus.lab.toulouse-stg.fr.ibm.com (unknown [9.145.51.101]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTP id A886852043; Mon, 9 Oct 2017 10:03:26 +0100 (BST) 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 , Andrea Arcangeli , Alexei Starovoitov Subject: [PATCH v4 19/20] x86/mm: Add speculative pagefault handling Date: Mon, 9 Oct 2017 12:07:51 +0200 X-Mailer: git-send-email 2.7.4 In-Reply-To: <1507543672-25821-1-git-send-email-ldufour@linux.vnet.ibm.com> References: <1507543672-25821-1-git-send-email-ldufour@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 17100910-0020-0000-0000-000003BEC52F X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17100910-0021-0000-0000-000042512B87 Message-Id: <1507543672-25821-20-git-send-email-ldufour@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2017-10-09_02:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1707230000 definitions=main-1710090148 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.24 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linuxppc-dev@lists.ozlabs.org, x86@kernel.org, linux-kernel@vger.kernel.org, npiggin@gmail.com, linux-mm@kvack.org, Tim Chen , haren@linux.vnet.ibm.com, khandual@linux.vnet.ibm.com Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" From: Peter Zijlstra Try a speculative fault before acquiring mmap_sem, if it returns with VM_FAULT_RETRY continue with the mmap_sem acquisition and do the traditional fault. Signed-off-by: Peter Zijlstra (Intel) [Clearing of FAULT_FLAG_ALLOW_RETRY is now done in handle_speculative_fault()] [Retry with usual fault path in the case VM_ERROR is returned by handle_speculative_fault(). This allows signal to be delivered] [Don't build SPF call if !__HAVE_ARCH_CALL_SPF] Signed-off-by: Laurent Dufour --- arch/x86/include/asm/pgtable_types.h | 7 +++++++ arch/x86/mm/fault.c | 21 +++++++++++++++++++++ 2 files changed, 28 insertions(+) diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h index f1492473f10e..48c7e587eac4 100644 --- a/arch/x86/include/asm/pgtable_types.h +++ b/arch/x86/include/asm/pgtable_types.h @@ -257,6 +257,13 @@ enum page_cache_mode { #define PGD_IDENT_ATTR 0x001 /* PRESENT (no other attributes) */ #endif +/* + * Advertise that we call the Speculative Page Fault handler. + */ +#if defined(CONFIG_X86_64) && defined(CONFIG_SMP) +#define __HAVE_ARCH_CALL_SPF +#endif + #ifdef CONFIG_X86_32 # include #else diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index e2baeaa053a5..802dc7d914a2 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -1364,6 +1364,24 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code, if (error_code & PF_INSTR) flags |= FAULT_FLAG_INSTRUCTION; +#ifdef __HAVE_ARCH_CALL_SPF + if (error_code & PF_USER) { + fault = handle_speculative_fault(mm, address, flags); + + /* + * We also check against VM_FAULT_ERROR because we have to + * raise a signal by calling later mm_fault_error() which + * requires the vma pointer to be set. So in that case, + * we fall through the normal path. + */ + if (!(fault & VM_FAULT_RETRY || fault & VM_FAULT_ERROR)) { + perf_sw_event(PERF_COUNT_SW_SPF, 1, + regs, address); + goto done; + } + } +#endif /* __HAVE_ARCH_CALL_SPF */ + /* * When running in the kernel we expect faults to occur only to * addresses in user space. All other faults represent errors in @@ -1474,6 +1492,9 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code, return; } +#ifdef __HAVE_ARCH_CALL_SPF +done: +#endif /* * Major/minor page fault accounting. If any of the events * returned VM_FAULT_MAJOR, we account it as a major fault.