Re: nvmf regression with mq-deadline
From: Sagi Grimberg <sagi@grimberg.me>
Date: 2017-02-27 13:31:44
Also in:
linux-nvme
quoted hunk ↗ jump to hunk
Hey Jens, I'm getting a regression in nvme-rdma/nvme-loop with for-linus [1] with a small script to trigger it. The reason seems to be that the sched_tags does not take into account the tag_set reserved tags. This solves it for me, any objections on this? --diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c index 98c7b061781e..46ca965fff5c 100644 --- a/block/blk-mq-sched.c +++ b/block/blk-mq-sched.c@@ -454,7 +454,8 @@ int blk_mq_sched_setup(struct request_queue *q) */ ret = 0; queue_for_each_hw_ctx(q, hctx, i) { - hctx->sched_tags = blk_mq_alloc_rq_map(set, i,q->nr_requests, 0); + hctx->sched_tags = blk_mq_alloc_rq_map(set, i, + q->nr_requests, set->reserved_tags); if (!hctx->sched_tags) { ret = -ENOMEM; break; --
Now I'm getting a NULL deref with nvme-rdma [1]. For some reason blk_mq_tag_to_rq() is returning NULL on tag 0x0 which is io queue connect. I'll try to see where this is coming from. This does not happen with loop though... -- [ 30.431889] nvme nvme0: creating 2 I/O queues. [ 30.465458] nvme nvme0: tag 0x0 on QP 0x84 not found [ 36.060168] BUG: unable to handle kernel NULL pointer dereference at 0000000000000030 [ 36.063277] IP: bt_iter+0x31/0x50 [ 36.064088] PGD 0 [ 36.064088] Oops: 0000 [#1] SMP [ 36.064088] Modules linked in: nvme_rdma nvme_fabrics nvme_core mlx5_ib ppdev kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcbc aesni_intel aes_x86_64 crypto_simd glue_helper cryptd i2c_piix4 joydev input_leds serio_raw parport_pc parport mac_hid ib_iser rdma_cm iw_cm ib_cm ib_core configfs iscsi_tcp libiscsi_tcp libiscsi sunrpc scsi_transport_iscsi autofs4 cirrus ttm drm_kms_helper syscopyarea sysfillrect mlx5_core sysimgblt fb_sys_fops psmouse drm floppy ptp pata_acpi pps_core [ 36.064088] CPU: 0 PID: 186 Comm: kworker/0:1H Not tainted 4.10.0+ #115 [ 36.064088] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 [ 36.064088] Workqueue: kblockd blk_mq_timeout_work [ 36.064088] task: ffff95f6393a0080 task.stack: ffffb826803ac000 [ 36.064088] RIP: 0010:bt_iter+0x31/0x50 [ 36.064088] RSP: 0018:ffffb826803afda0 EFLAGS: 00010202 [ 36.064088] RAX: ffffb826803afdd0 RBX: ffff95f63c036800 RCX: 0000000000000001 [ 36.064088] RDX: ffff95f635ff0798 RSI: 0000000000000000 RDI: ffff95f63c036800 [ 36.064088] RBP: ffffb826803afe18 R08: 0000000000000000 R09: 0000000000000001 [ 36.064088] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 36.064088] R13: ffff95f635d7c240 R14: 0000000000000000 R15: ffff95f63c47ff00 [ 36.064088] FS: 0000000000000000(0000) GS:ffff95f63fc00000(0000) knlGS:0000000000000000 [ 36.064088] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 36.064088] CR2: 0000000000000030 CR3: 000000003c8db000 CR4: 00000000003406f0 [ 36.064088] Call Trace: [ 36.064088] ? blk_mq_queue_tag_busy_iter+0x191/0x1d0 [ 36.064088] ? blk_mq_rq_timed_out+0x70/0x70 [ 36.064088] ? blk_mq_rq_timed_out+0x70/0x70 [ 36.064088] blk_mq_timeout_work+0xba/0x160 [ 36.064088] process_one_work+0x16b/0x480 [ 36.064088] worker_thread+0x4b/0x500 [ 36.064088] kthread+0x101/0x140 [ 36.064088] ? process_one_work+0x480/0x480 [ 36.064088] ? kthread_create_on_node+0x40/0x40 [ 36.064088] ret_from_fork+0x2c/0x40 [ 36.064088] Code: 89 d0 48 8b 3a 0f b6 48 18 48 8b 97 08 01 00 00 84 c9 75 03 03 72 04 48 8b 92 80 00 00 00 89 f6 48 8b 34 f2 48 8b 97 98 00 00 00 <48> 39 56 30 74 06 b8 01 00 00 00 c3 55 48 8b 50 10 48 89 e5 ff [ 36.064088] RIP: bt_iter+0x31/0x50 RSP: ffffb826803afda0 [ 36.064088] CR2: 0000000000000030 [ 36.064088] ---[ end trace 469df54df5f3cd87 ]--- -- _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme