From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E924AC282DA for ; Tue, 16 Apr 2019 13:47:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B81B121B26 for ; Tue, 16 Apr 2019 13:47:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729604AbfDPNrR (ORCPT ); Tue, 16 Apr 2019 09:47:17 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:42152 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729563AbfDPNrQ (ORCPT ); Tue, 16 Apr 2019 09:47:16 -0400 Received: from pps.filterd (m0098420.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x3GDkcQC175912 for ; Tue, 16 Apr 2019 09:47:15 -0400 Received: from e06smtp03.uk.ibm.com (e06smtp03.uk.ibm.com [195.75.94.99]) by mx0b-001b2d01.pphosted.com with ESMTP id 2rwfbattgt-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 16 Apr 2019 09:47:11 -0400 Received: from localhost by e06smtp03.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 16 Apr 2019 14:47:01 +0100 Received: from b06cxnps4076.portsmouth.uk.ibm.com (9.149.109.198) by e06smtp03.uk.ibm.com (192.168.101.133) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Tue, 16 Apr 2019 14:46:51 +0100 Received: from d06av22.portsmouth.uk.ibm.com (d06av22.portsmouth.uk.ibm.com [9.149.105.58]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x3GDknUt21561348 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 16 Apr 2019 13:46:49 GMT Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 594DE4C044; Tue, 16 Apr 2019 13:46:49 +0000 (GMT) Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id D75944C05E; Tue, 16 Apr 2019 13:46:47 +0000 (GMT) Received: from nimbus.lab.toulouse-stg.fr.ibm.com (unknown [9.101.4.33]) by d06av22.portsmouth.uk.ibm.com (Postfix) with ESMTP; Tue, 16 Apr 2019 13:46:47 +0000 (GMT) From: Laurent Dufour To: akpm@linux-foundation.org, mhocko@kernel.org, peterz@infradead.org, kirill@shutemov.name, ak@linux.intel.com, dave@stgolabs.net, jack@suse.cz, Matthew Wilcox , aneesh.kumar@linux.ibm.com, benh@kernel.crashing.org, mpe@ellerman.id.au, paulus@samba.org, Thomas Gleixner , Ingo Molnar , hpa@zytor.com, Will Deacon , Sergey Senozhatsky , sergey.senozhatsky.work@gmail.com, Andrea Arcangeli , Alexei Starovoitov , kemi.wang@intel.com, Daniel Jordan , David Rientjes , Jerome Glisse , Ganesh Mahendran , Minchan Kim , Punit Agrawal , vinayak menon , Yang Shi , zhong jiang , Haiyan Song , Balbir Singh , sj38.park@gmail.com, Michel Lespinasse , Mike Rapoport Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, haren@linux.vnet.ibm.com, npiggin@gmail.com, paulmck@linux.vnet.ibm.com, Tim Chen , linuxppc-dev@lists.ozlabs.org, x86@kernel.org Subject: [PATCH v12 30/31] arm64/mm: add speculative page fault Date: Tue, 16 Apr 2019 15:45:21 +0200 X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190416134522.17540-1-ldufour@linux.ibm.com> References: <20190416134522.17540-1-ldufour@linux.ibm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 x-cbid: 19041613-0012-0000-0000-0000030F6F13 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19041613-0013-0000-0000-00002147A86B Message-Id: <20190416134522.17540-31-ldufour@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-04-16_05:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1904160093 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Mahendran Ganesh This patch enables the speculative page fault on the arm64 architecture. I completed spf porting in 4.9. From the test result, we can see app launching time improved by about 10% in average. For the apps which have more than 50 threads, 15% or even more improvement can be got. Signed-off-by: Ganesh Mahendran [handle_speculative_fault() is no more returning the vma pointer] Signed-off-by: Laurent Dufour --- arch/arm64/mm/fault.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index 4f343e603925..b5e2a93f9c21 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -485,6 +485,16 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr, perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr); + /* + * let's try a speculative page fault without grabbing the + * mmap_sem. + */ + fault = handle_speculative_fault(mm, addr, mm_flags); + if (fault != VM_FAULT_RETRY) { + perf_sw_event(PERF_COUNT_SW_SPF, 1, regs, addr); + goto done; + } + /* * As per x86, we may deadlock here. However, since the kernel only * validly references user space from well defined areas of the code, @@ -535,6 +545,8 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr, } up_read(&mm->mmap_sem); +done: + /* * Handle the "normal" (no error) case first. */ -- 2.21.0