-------- Forwarded Message -------- Subject: max_unmap_lba_count too large by default Date: Thu, 27 Aug 2015 16:47:48 +0200 From: Tomasz Charoński t.charonski@beyond.pl To: targetcli-fb-devel-bounces@lists.fedorahosted.org
Hello,
the attribute max_unmap_lba_count of iblock backstore (maybe in other backstores too) is definitely too large by default: 4194304. It allows SCSI to accept so big SCSI unmap commands, that target eventually ends with timeout, because backend storage processes it too long:
Aug 17 09:51:01 debian8 kernel: [330755.353723] INFO: task kworker/10:1:5423 blocked for more than 120 seconds. Aug 17 09:51:01 debian8 kernel: [330755.353773] Tainted: P O 4.0.4 #1 Aug 17 09:51:01 debian8 kernel: [330755.353807] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. Aug 17 09:51:01 debian8 kernel: [330755.353867] kworker/10:1 D ffff88203f014440 0 5423 2 0x00000000 Aug 17 09:51:01 debian8 kernel: [330755.353884] Workqueue: tcm_qla2xxx_free tcm_qla2xxx_handle_data_work [tcm_qla2xxx] Aug 17 09:51:01 debian8 kernel: [330755.353888] ffff882021f722d0 ffff88149219fbf8 ffff881038c7a190 0000000000000001 Aug 17 09:51:01 debian8 kernel: [330755.353893] ffff88149219ffd8 ffff88203f014440 7fffffffffffffff ffff882021f722d0 Aug 17 09:51:01 debian8 kernel: [330755.353896] ffff88149219fcd0 0000000000000000 ffffffff815640cf 0000000000000000 Aug 17 09:51:01 debian8 kernel: [330755.353901] Call Trace: Aug 17 09:51:01 debian8 kernel: [330755.353918] [<ffffffff815640cf>] ? schedule+0x2f/0x80 Aug 17 09:51:01 debian8 kernel: [330755.353924] [<ffffffff8156744a>] ? schedule_timeout+0x21a/0x290 Aug 17 09:51:01 debian8 kernel: [330755.353936] [<ffffffff812a5eaf>] ? generic_make_request_checks+0x1df/0x3d0 Aug 17 09:51:01 debian8 kernel: [330755.353947] [<ffffffff8101cf75>] ? read_tsc+0x5/0x10 Aug 17 09:51:01 debian8 kernel: [330755.353952] [<ffffffff815636ea>] ? io_schedule_timeout+0xba/0x150 Aug 17 09:51:01 debian8 kernel: [330755.353957] [<ffffffff81564ab5>] ? wait_for_completion_io+0xb5/0x180 Aug 17 09:51:01 debian8 kernel: [330755.353967] [<ffffffff81098fa0>] ? wake_up_state+0x20/0x20 Aug 17 09:51:01 debian8 kernel: [330755.353973] [<ffffffff812b0fab>] ? blkdev_issue_discard+0x20b/0x270 Aug 17 09:51:01 debian8 kernel: [330755.353983] [<ffffffffa0543270>] ? iblock_execute_unmap+0x30/0x30 [target_core_iblock] Aug 17 09:51:01 debian8 kernel: [330755.353988] [<ffffffffa054328f>] ? iblock_do_unmap+0x1f/0x50 [target_core_iblock] Aug 17 09:51:01 debian8 kernel: [330755.354003] [<ffffffffa07af65c>] ? sbc_execute_unmap+0x12c/0x270 [target_core_mod] Aug 17 09:51:01 debian8 kernel: [330755.354010] [<ffffffff810125eb>] ? __switch_to+0x14b/0x5d0 Aug 17 09:51:01 debian8 kernel: [330755.354020] [<ffffffffa07ac4aa>] ? __target_execute_cmd+0x1a/0xa0 [target_core_mod] Aug 17 09:51:01 debian8 kernel: [330755.354026] [<ffffffff81086a02>] ? process_one_work+0x152/0x440 Aug 17 09:51:01 debian8 kernel: [330755.354031] [<ffffffff8108757b>] ? worker_thread+0x6b/0x560 Aug 17 09:51:01 debian8 kernel: [330755.354035] [<ffffffff81087510>] ? rescuer_thread+0x3b0/0x3b0 Aug 17 09:51:01 debian8 kernel: [330755.354041] [<ffffffff8108c533>] ? kthread+0xd3/0xf0 Aug 17 09:51:01 debian8 kernel: [330755.354045] [<ffffffff8108c460>] ? kthread_create_on_node+0x180/0x180 Aug 17 09:51:01 debian8 kernel: [330755.354050] [<ffffffff81568798>] ? ret_from_fork+0x58/0x90 Aug 17 09:51:01 debian8 kernel: [330755.354054] [<ffffffff8108c460>] ? kthread_create_on_node+0x180/0x180
To prevent such timeouts I suggest to set max_unmap_lba_count by default to 65535.
Best regards,
targetcli-fb-devel@lists.fedorahosted.org