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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT 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 9BCA5C04EB8 for ; Fri, 7 Dec 2018 03:00:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5DC2A2083D for ; Fri, 7 Dec 2018 03:00:43 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5DC2A2083D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-block-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725948AbeLGDAm (ORCPT ); Thu, 6 Dec 2018 22:00:42 -0500 Received: from mx1.redhat.com ([209.132.183.28]:42608 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725939AbeLGDAm (ORCPT ); Thu, 6 Dec 2018 22:00:42 -0500 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id EFB1290C7B; Fri, 7 Dec 2018 03:00:41 +0000 (UTC) Received: from ming.t460p (ovpn-8-23.pek2.redhat.com [10.72.8.23]) by smtp.corp.redhat.com (Postfix) with ESMTPS id B8F535C1A1; Fri, 7 Dec 2018 03:00:35 +0000 (UTC) Date: Fri, 7 Dec 2018 11:00:29 +0800 From: Ming Lei To: Jens Axboe Cc: linux-block@vger.kernel.org, Christoph Hellwig , linux-nvme@lists.infradead.org, David Milburn Subject: Re: [PATCH] blk-mq: re-build queue map in case of kdump kernel Message-ID: <20181207030028.GA22188@ming.t460p> References: <20181207025523.22703-1-ming.lei@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.1 (2017-09-22) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Fri, 07 Dec 2018 03:00:42 +0000 (UTC) Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Thu, Dec 06, 2018 at 07:57:34PM -0700, Jens Axboe wrote: > On 12/6/18 7:55 PM, Ming Lei wrote: > > Now almost all .map_queues() implementation based on managed irq > > affinity doesn't update queue mapping and it just retrieves the > > old built mapping, so if nr_hw_queues is changed, the mapping talbe > > includes stale mapping. And only blk_mq_map_queues() may rebuild > > the mapping talbe. > > > > One case is that we limit .nr_hw_queues as 1 in case of kdump kernel. > > However, drivers often builds queue mapping before allocating tagset > > via pci_alloc_irq_vectors_affinity(), but set->nr_hw_queues can be set > > as 1 in case of kdump kernel, so wrong queue mapping is used, and > > kernel panic[1] is observed during booting. > > > > This patch fixes the kernel panic triggerd on nvme by rebulding the > > mapping table via blk_mq_map_queues(). > > > > [1] kernel panic log > > [ 4.438371] nvme nvme0: 16/0/0 default/read/poll queues > > [ 4.443277] BUG: unable to handle kernel NULL pointer dereference at 0000000000000098 > > [ 4.444681] PGD 0 P4D 0 > > [ 4.445367] Oops: 0000 [#1] SMP NOPTI > > [ 4.446342] CPU: 3 PID: 201 Comm: kworker/u33:10 Not tainted 4.20.0-rc5-00664-g5eb02f7ee1eb-dirty #459 > > [ 4.447630] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.10.2-2.fc27 04/01/2014 > > [ 4.448689] Workqueue: nvme-wq nvme_scan_work [nvme_core] > > [ 4.449368] RIP: 0010:blk_mq_map_swqueue+0xfb/0x222 > > [ 4.450596] Code: 04 f5 20 28 ef 81 48 89 c6 39 55 30 76 93 89 d0 48 c1 e0 04 48 03 83 f8 05 00 00 48 8b 00 42 8b 3c 28 48 8b 43 58 48 8b 04 f8 <48> 8b b8 98 00 00 00 4c 0f a3 37 72 42 f0 4c 0f ab 37 66 8b b8 f6 > > [ 4.453132] RSP: 0018:ffffc900023b3cd8 EFLAGS: 00010286 > > [ 4.454061] RAX: 0000000000000000 RBX: ffff888174448000 RCX: 0000000000000001 > > [ 4.456480] RDX: 0000000000000001 RSI: ffffe8feffc506c0 RDI: 0000000000000001 > > [ 4.458750] RBP: ffff88810722d008 R08: ffff88817647a880 R09: 0000000000000002 > > [ 4.464580] R10: ffffc900023b3c10 R11: 0000000000000004 R12: ffff888174448538 > > [ 4.467803] R13: 0000000000000004 R14: 0000000000000001 R15: 0000000000000001 > > [ 4.469220] FS: 0000000000000000(0000) GS:ffff88817bac0000(0000) knlGS:0000000000000000 > > [ 4.471554] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > [ 4.472464] CR2: 0000000000000098 CR3: 0000000174e4e001 CR4: 0000000000760ee0 > > [ 4.474264] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > > [ 4.476007] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > > [ 4.477061] PKRU: 55555554 > > [ 4.477464] Call Trace: > > [ 4.478731] blk_mq_init_allocated_queue+0x36a/0x3ad > > [ 4.479595] blk_mq_init_queue+0x32/0x4e > > [ 4.480178] nvme_validate_ns+0x98/0x623 [nvme_core] > > [ 4.480963] ? nvme_submit_sync_cmd+0x1b/0x20 [nvme_core] > > [ 4.481685] ? nvme_identify_ctrl.isra.8+0x70/0xa0 [nvme_core] > > [ 4.482601] nvme_scan_work+0x23a/0x29b [nvme_core] > > [ 4.483269] ? _raw_spin_unlock_irqrestore+0x25/0x38 > > [ 4.483930] ? try_to_wake_up+0x38d/0x3b3 > > [ 4.484478] ? process_one_work+0x179/0x2fc > > [ 4.485118] process_one_work+0x1d3/0x2fc > > [ 4.485655] ? rescuer_thread+0x2ae/0x2ae > > [ 4.486196] worker_thread+0x1e9/0x2be > > [ 4.486841] kthread+0x115/0x11d > > [ 4.487294] ? kthread_park+0x76/0x76 > > [ 4.487784] ret_from_fork+0x3a/0x50 > > [ 4.488322] Modules linked in: nvme nvme_core qemu_fw_cfg virtio_scsi ip_tables > > [ 4.489428] Dumping ftrace buffer: > > [ 4.489939] (ftrace buffer empty) > > [ 4.490492] CR2: 0000000000000098 > > [ 4.491052] ---[ end trace 03cd268ad5a86ff7 ]--- > > > > Cc: Christoph Hellwig > > Cc: linux-nvme@lists.infradead.org > > Cc: David Milburn > > Signed-off-by: Ming Lei > > --- > > block/blk-mq.c | 12 +++++++++--- > > 1 file changed, 9 insertions(+), 3 deletions(-) > > > > diff --git a/block/blk-mq.c b/block/blk-mq.c > > index 900550594651..a3e463a726a6 100644 > > --- a/block/blk-mq.c > > +++ b/block/blk-mq.c > > @@ -38,6 +38,11 @@ > > #include "blk-mq-sched.h" > > #include "blk-rq-qos.h" > > > > +static inline bool blk_mq_kdump_kernel(void) > > +{ > > + return !!is_kdump_kernel(); > > +} > > Let's drop the redundant !! here, and the wrapper? I would imagine the > wrapper is handy for testing outside of kdump, but I don't think we > should include it in the final. OK. Thanks, Ming