From patchwork Wed Jul 29 08:45:18 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ritesh Harjani X-Patchwork-Id: 11690657 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id BA1ED13B6 for ; Wed, 29 Jul 2020 08:45:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ABC3F20838 for ; Wed, 29 Jul 2020 08:45:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728129AbgG2Ipd (ORCPT ); Wed, 29 Jul 2020 04:45:33 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:19810 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727054AbgG2Ipc (ORCPT ); Wed, 29 Jul 2020 04:45:32 -0400 Received: from pps.filterd (m0098420.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 06T8WR1Q053522; Wed, 29 Jul 2020 04:45:30 -0400 Received: from ppma03ams.nl.ibm.com (62.31.33a9.ip4.static.sl-reverse.com [169.51.49.98]) by mx0b-001b2d01.pphosted.com with ESMTP id 32jpw40reg-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 29 Jul 2020 04:45:29 -0400 Received: from pps.filterd (ppma03ams.nl.ibm.com [127.0.0.1]) by ppma03ams.nl.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 06T8TnkI026980; Wed, 29 Jul 2020 08:45:28 GMT Received: from b06avi18626390.portsmouth.uk.ibm.com (b06avi18626390.portsmouth.uk.ibm.com [9.149.26.192]) by ppma03ams.nl.ibm.com with ESMTP id 32gcpx4u4c-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 29 Jul 2020 08:45:27 +0000 Received: from d06av25.portsmouth.uk.ibm.com (d06av25.portsmouth.uk.ibm.com [9.149.105.61]) by b06avi18626390.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 06T8i0xC55640444 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 29 Jul 2020 08:44:00 GMT Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 36A6A11C05C; Wed, 29 Jul 2020 08:45:25 +0000 (GMT) Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id E610911C050; Wed, 29 Jul 2020 08:45:23 +0000 (GMT) Received: from localhost.localdomain.com (unknown [9.199.33.112]) by d06av25.portsmouth.uk.ibm.com (Postfix) with ESMTP; Wed, 29 Jul 2020 08:45:23 +0000 (GMT) From: Ritesh Harjani To: linux-nvdimm@lists.01.org Cc: linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org, linux-kernel@vger.kernel.org, Ritesh Harjani , "Aneesh Kumar K . V" Subject: [RFC 1/1] pmem: Add cond_resched() in bio_for_each_segment loop in pmem_make_request Date: Wed, 29 Jul 2020 14:15:18 +0530 Message-Id: <0d96e2481f292de2cda8828b03d5121004308759.1596011292.git.riteshh@linux.ibm.com> X-Mailer: git-send-email 2.25.4 MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235,18.0.687 definitions=2020-07-29_03:2020-07-28,2020-07-29 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxscore=0 bulkscore=0 adultscore=0 lowpriorityscore=0 priorityscore=1501 mlxlogscore=842 malwarescore=0 spamscore=0 impostorscore=0 suspectscore=1 clxscore=1011 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2007290055 Sender: linux-xfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org For systems which do not have CONFIG_PREEMPT set and if there is a heavy multi-threaded load/store operation happening on pmem + sometimes along with device latencies, softlockup warnings like this could trigger. This was seen on Power where pagesize is 64K. To avoid softlockup, this patch adds a cond_resched() in this path. <...> watchdog: BUG: soft lockup - CPU#31 stuck for 22s! <...> CPU: 31 PID: 15627 <..> 5.3.18-20 <...> NIP memcpy_power7+0x43c/0x7e0 LR memcpy_flushcache+0x28/0xa0 Call Trace: memcpy_power7+0x274/0x7e0 (unreliable) memcpy_flushcache+0x28/0xa0 write_pmem+0xa0/0x100 [nd_pmem] pmem_do_bvec+0x1f0/0x420 [nd_pmem] pmem_make_request+0x14c/0x370 [nd_pmem] generic_make_request+0x164/0x400 submit_bio+0x134/0x2e0 submit_bio_wait+0x70/0xc0 blkdev_issue_zeroout+0xf4/0x2a0 xfs_zero_extent+0x90/0xc0 [xfs] xfs_bmapi_convert_unwritten+0x198/0x230 [xfs] xfs_bmapi_write+0x284/0x630 [xfs] xfs_iomap_write_direct+0x1f0/0x3e0 [xfs] xfs_file_iomap_begin+0x344/0x690 [xfs] dax_iomap_pmd_fault+0x488/0xc10 __xfs_filemap_fault+0x26c/0x2b0 [xfs] __handle_mm_fault+0x794/0x1af0 handle_mm_fault+0x12c/0x220 __do_page_fault+0x290/0xe40 do_page_fault+0x38/0xc0 handle_page_fault+0x10/0x30 Reviewed-by: Aneesh Kumar K.V Signed-off-by: Ritesh Harjani --- drivers/nvdimm/pmem.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index 2df6994acf83..fcf7af13897e 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -214,6 +214,7 @@ static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio) bio->bi_status = rc; break; } + cond_resched(); } if (do_acct) nd_iostat_end(bio, start);