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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 58370C6778F for ; Fri, 27 Jul 2018 14:10:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 12ACE2064D for ; Fri, 27 Jul 2018 14:10:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 12ACE2064D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.vnet.ibm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732841AbeG0Pcj (ORCPT ); Fri, 27 Jul 2018 11:32:39 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:49850 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1732059AbeG0Pci (ORCPT ); Fri, 27 Jul 2018 11:32:38 -0400 Received: from pps.filterd (m0098420.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w6RE9M6f079663 for ; Fri, 27 Jul 2018 10:10:31 -0400 Received: from e06smtp02.uk.ibm.com (e06smtp02.uk.ibm.com [195.75.94.98]) by mx0b-001b2d01.pphosted.com with ESMTP id 2kg24uxy1p-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Fri, 27 Jul 2018 10:10:30 -0400 Received: from localhost by e06smtp02.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Fri, 27 Jul 2018 15:10:28 +0100 Received: from d06av23.portsmouth.uk.ibm.com (d06av23.portsmouth.uk.ibm.com [9.149.105.59]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w6REARsS15269928 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Fri, 27 Jul 2018 14:10:27 GMT Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 9F121A406B; Fri, 27 Jul 2018 17:10:40 +0100 (BST) Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 675A3A4057; Fri, 27 Jul 2018 17:10:40 +0100 (BST) Received: from [9.145.62.135] (unknown [9.145.62.135]) by d06av23.portsmouth.uk.ibm.com (Postfix) with ESMTP; Fri, 27 Jul 2018 17:10:40 +0100 (BST) Subject: Re: [PATCH 0/3] powerpc/pseries: use H_BLOCK_REMOVE From: Laurent Dufour To: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org References: <1532697739-4878-1-git-send-email-ldufour@linux.vnet.ibm.com> Date: Fri, 27 Jul 2018 16:10:26 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <1532697739-4878-1-git-send-email-ldufour@linux.vnet.ibm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 x-cbid: 18072714-0008-0000-0000-00000258A19E X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18072714-0009-0000-0000-000021BF27BE Message-Id: <4860026b-4d69-a42e-81eb-8599059bb964@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-07-27_06:,, 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=450 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1806210000 definitions=main-1807270146 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Sorry for the noise, I forgot to add CC people in copy of this cover. A wall new thread has been resent : https://lkml.org/lkml/2018/7/27/651 On 27/07/2018 15:22, Laurent Dufour wrote: > On very large system we could see soft lockup fired when a process is exiting > > watchdog: BUG: soft lockup - CPU#851 stuck for 21s! [forkoff:215523] > Modules linked in: pseries_rng rng_core xfs raid10 vmx_crypto btrfs libcrc32c xor zstd_decompress zstd_compress xxhash lzo_compress raid6_pq crc32c_vpmsum lpfc crc_t10dif crct10dif_generic crct10dif_common dm_multipath scsi_dh_rdac scsi_dh_alua autofs4 > CPU: 851 PID: 215523 Comm: forkoff Not tainted 4.17.0 #1 > NIP: c0000000000b995c LR: c0000000000b8f64 CTR: 000000000000aa18 > REGS: c00006b0645b7610 TRAP: 0901 Not tainted (4.17.0) > MSR: 800000010280b033 CR: 22042082 XER: 00000000 > CFAR: 00000000006cf8f0 SOFTE: 0 > GPR00: 0010000000000000 c00006b0645b7890 c000000000f99200 0000000000000000 > GPR04: 8e000001a5a4de58 400249cf1bfd5480 8e000001a5a4de50 400249cf1bfd5480 > GPR08: 8e000001a5a4de48 400249cf1bfd5480 8e000001a5a4de40 400249cf1bfd5480 > GPR12: ffffffffffffffff c00000001e690800 > NIP [c0000000000b995c] plpar_hcall9+0x44/0x7c > LR [c0000000000b8f64] pSeries_lpar_flush_hash_range+0x324/0x3d0 > Call Trace: > [c00006b0645b7890] [8e000001a5a4dd20] 0x8e000001a5a4dd20 (unreliable) > [c00006b0645b7a00] [c00000000006d5b0] flush_hash_range+0x60/0x110 > [c00006b0645b7a50] [c000000000072a2c] __flush_tlb_pending+0x4c/0xd0 > [c00006b0645b7a80] [c0000000002eaf44] unmap_page_range+0x984/0xbd0 > [c00006b0645b7bc0] [c0000000002eb594] unmap_vmas+0x84/0x100 > [c00006b0645b7c10] [c0000000002f8afc] exit_mmap+0xac/0x1f0 > [c00006b0645b7cd0] [c0000000000f2638] mmput+0x98/0x1b0 > [c00006b0645b7d00] [c0000000000fc9d0] do_exit+0x330/0xc00 > [c00006b0645b7dc0] [c0000000000fd384] do_group_exit+0x64/0x100 > [c00006b0645b7e00] [c0000000000fd44c] sys_exit_group+0x2c/0x30 > [c00006b0645b7e30] [c00000000000b960] system_call+0x58/0x6c > Instruction dump: > 60000000 f8810028 7ca42b78 7cc53378 7ce63b78 7d074378 7d284b78 7d495378 > e9410060 e9610068 e9810070 44000022 <7d806378> e9810028 f88c0000 f8ac0008 > > This happens when removing the PTE by calling the hypervisor using the > H_BULK_REMOVE call. This call is processing up to 4 PTEs but is doing a > tlbie for each PTE it is processing. This could lead to long time spent in > the hypervisor (sometimes up to 4s) and soft lockup being raised because > the scheduler is not called in zap_pte_range(). > > Since the Power7's time, the hypervisor is providing a new hcall > H_BLOCK_REMOVE allowing processing up to 8 PTEs with one call to > tlbie. By limiting the amount of tlbie generated, this reduces the time > spent invalidating the PTEs. > > This hcall requires that the pages are "all within the same naturally > aligned 8 page virtual address block". > > With this patch series applied, I couldn't see any soft lockup raised on > the victim LPAR I was running the test one. > > This series is covering both normal pages and huge pages. > > Laurent Dufour (3): > powerpc/pseries/mm: Introducing FW_FEATURE_BLOCK_REMOVE > powerpc/pseries/mm: factorize PTE slot computation > powerpc/pseries/mm: call H_BLOCK_REMOVE > > arch/powerpc/include/asm/firmware.h | 3 +- > arch/powerpc/include/asm/hvcall.h | 1 + > arch/powerpc/platforms/pseries/firmware.c | 1 + > arch/powerpc/platforms/pseries/lpar.c | 250 ++++++++++++++++++++++++++---- > 4 files changed, 228 insertions(+), 27 deletions(-) >