On 12/11/18 3:58 PM, Bart Van Assche wrote: > Hi Jens, > > If I run the following subset of blktests: > > while :; do ./check -q srp && ./check -q nvmeof-mp; done > > against today's for-next branch (commit dd2bf2df85a7) then after some > time the following hang is reported: > > INFO: task fio:14869 blocked for more than 120 seconds. > Not tainted 4.20.0-rc6-dbg+ #1 > "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > fio D25272 14869 14195 0x00000000 > Call Trace: > __schedule+0x401/0xe50 > schedule+0x4e/0xd0 > io_schedule+0x21/0x50 > blk_mq_get_tag+0x46d/0x640 > blk_mq_get_request+0x7c0/0xa00 > blk_mq_make_request+0x241/0xa70 > generic_make_request+0x411/0x950 > submit_bio+0x9b/0x250 > blkdev_direct_IO+0x7fb/0x870 > generic_file_direct_write+0x119/0x210 > __generic_file_write_iter+0x11c/0x280 > blkdev_write_iter+0x13c/0x220 > aio_write+0x204/0x310 > io_submit_one+0x9c6/0xe70 > __x64_sys_io_submit+0x115/0x340 > do_syscall_64+0x71/0x210 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > When that hang occurs my list-pending-block-requests script does not show > any pending requests: > > # list-pending-block-requests > dm-0 > loop0 > loop1 > loop2 > loop3 > loop4 > loop5 > loop6 > loop7 > nullb0 > nullb1 > sda > sdb > sdc > sdd > vda > vdb > > Enabling fail_if_no_path mode did not resolve the hang so I don't think > that the root cause is in any of the dm drivers used in this test: > > # dmsetup ls | while read dm rest; do dmsetup message $dm 0 fail_if_no_path; done; dmsetup remove_all; dmsetup table > 360014056e756c6c62300000000000000: 0 65536 multipath 0 1 alua 1 1 service-time 0 1 2 8:16 1 1 > > The same test passes against kernel v4.20-rc6. What device is this being run on? -- Jens Axboe
