Hi, I'm experiencing a possible bcache-hang in my setup. Mainboard: Asrock Rack EP2C602 CPU: 2x Intel Xeon E5-2670 Linux: 4.8.13-1-ARCH Cache-device: Partition on Samsung SSD 850 EVO 500GB Backing-device: 500GB Western Digital Black Bcache is running in writeback mode. On top of bcache, I'm running LVM, which provides a Games-LV for a Qemu Windows-10 VM (Games-HD with drive letter 'D'. Drive C is hosted on a non-bcache block device. Each VM has its own GPU via passthrough). For a second/third VM, I create snapshots of the Games-LV. When playing the game Overwatch, the first VM suddenly stops to respond (after about >20min), some seconds later the second VM, too. Currently I'm not near the machine with the problem, but I'm appending as much information as possible. Regards, Jan $ bcache-super-show /dev/sdb6 sb.magic ok sb.first_sector 8 [match] sb.csum 617AC6C2ABF15A0D [match] sb.version 3 [cache device] dev.label (empty) dev.uuid 73ec71d1-1353-4cc0-8b06-d798b44d593e dev.sectors_per_block 1 dev.sectors_per_bucket 1024 dev.cache.first_sector 1024 dev.cache.cache_sectors 204692480 dev.cache.total_sectors 204693504 dev.cache.ordered yes dev.cache.discard no dev.cache.pos 0 dev.cache.replacement 0 [lru] cset.uuid 025ec95a-c03b-481f-97e4-d6dab92ba6b1 $ dmesg [...] [ 3945.367318] INFO: task kworker/22:0:146 blocked for more than 120 seconds. [ 3945.369245] Not tainted 4.8.13-1-ARCH #1 [ 3945.371113] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 3945.372970] kworker/22:0 D ffff88046d2c3cd8 0 146 2 0x00000000 [ 3945.372982] Workqueue: events update_writeback_rate [bcache] [ 3945.372983] ffff88046d2c3cd8 00ff88046d2c3cd0 ffff88046148e3c0 ffff88046d270e40 [ 3945.372986] ffff88046fd97ff0 ffff88046d2c4000 ffff8804696f0ad8 ffff88046d2c3d10 [ 3945.372988] ffff8804696f0af0 ffff8804696f0b18 ffff88046d2c3cf0 ffffffff815f40ec [ 3945.372990] Call Trace: [ 3945.372995] [<ffffffff815f40ec>] schedule+0x3c/0x90 [ 3945.372997] [<ffffffff815f6669>] rwsem_down_read_failed+0xf9/0x150 [ 3945.372999] [<ffffffff8130bb08>] call_rwsem_down_read_failed+0x18/0x30 [ 3945.373000] [<ffffffff815f5f07>] down_read+0x17/0x30 [ 3945.373004] [<ffffffffa0056dc5>] update_writeback_rate+0x25/0x210 [bcache] [ 3945.373006] [<ffffffff81095ef5>] process_one_work+0x1e5/0x470 [ 3945.373008] [<ffffffff810961c8>] worker_thread+0x48/0x4e0 [ 3945.373009] [<ffffffff81096180>] ? process_one_work+0x470/0x470 [ 3945.373011] [<ffffffff8109be38>] kthread+0xd8/0xf0 [ 3945.373014] [<ffffffff8102c782>] ? __switch_to+0x2d2/0x630 [ 3945.373016] [<ffffffff815f823f>] ret_from_fork+0x1f/0x40 [ 3945.373018] [<ffffffff8109bd60>] ? kthread_worker_fn+0x170/0x170 [ 3945.373031] INFO: task bcache_writebac:343 blocked for more than 120 seconds. [ 3945.374945] Not tainted 4.8.13-1-ARCH #1 [ 3945.376837] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 3945.378724] bcache_writebac D ffff88046975fcb8 0 343 2 0x00000000 [ 3945.378735] ffff88046975fcb8 00ff88046fa17f80 ffffffff81a0d500 ffff88046978d580 [ 3945.378737] ffff88046978d500 ffff880469760000 ffff8804696f0ad8 ffff8804696f0ad8 [ 3945.378740] ffff8804696f0af0 ffffffff00000001 ffff88046975fcd0 ffffffff815f40ec [ 3945.378742] Call Trace: [ 3945.378744] [<ffffffff815f40ec>] schedule+0x3c/0x90 [ 3945.378746] [<ffffffff815f67f2>] rwsem_down_write_failed+0x132/0x2b0 [ 3945.378748] [<ffffffff8130bb37>] call_rwsem_down_write_failed+0x17/0x30 [ 3945.378750] [<ffffffff815f5f44>] down_write+0x24/0x40 [ 3945.378754] [<ffffffffa005747b>] bch_writeback_thread+0x6b/0x7f0 [bcache] [ 3945.378758] [<ffffffffa0057410>] ? write_dirty+0xb0/0xb0 [bcache] [ 3945.378762] [<ffffffff8109be38>] kthread+0xd8/0xf0 [ 3945.378763] [<ffffffff8102c782>] ? __switch_to+0x2d2/0x630 [ 3945.378765] [<ffffffff815f823f>] ret_from_fork+0x1f/0x40 [ 3945.378767] [<ffffffff8109bd60>] ? kthread_worker_fn+0x170/0x170 [ 3945.378777] INFO: task qemu-system-x86:829 blocked for more than 120 seconds. [ 3945.380619] Not tainted 4.8.13-1-ARCH #1 [ 3945.382501] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 3945.385458] qemu-system-x86 D ffff88046933b7a8 0 829 1 0x00000000 [ 3945.385461] ffff88046933b7a8 00ff88046933b7b0 ffff8808650faac0 ffff88086ab52ac0 [ 3945.385463] 8000000000000000 ffff88046933c000 ffff8804696f0ad8 ffff88046933b7e0 [ 3945.385465] ffff8804696f0af0 ffff8804696f0000 ffff88046933b7c0 ffffffff815f40ec [ 3945.385467] Call Trace: [ 3945.385470] [<ffffffff815f40ec>] schedule+0x3c/0x90 [ 3945.385471] [<ffffffff815f6669>] rwsem_down_read_failed+0xf9/0x150 [ 3945.385475] [<ffffffffa00457db>] ? bch_submit_bbio+0x2b/0x30 [bcache] [ 3945.385477] [<ffffffff8130bb08>] call_rwsem_down_read_failed+0x18/0x30 [ 3945.385478] [<ffffffff815f5f07>] down_read+0x17/0x30 [ 3945.385482] [<ffffffffa004ab9b>] cached_dev_make_request+0x63b/0xcb0 [bcache] [ 3945.385485] [<ffffffff812cd0e2>] generic_make_request+0xf2/0x1a0 [ 3945.385487] [<ffffffff812cd20d>] submit_bio+0x7d/0x150 [ 3945.385490] [<ffffffff8124a1e3>] __blockdev_direct_IO+0x31a3/0x4040 [ 3945.385493] [<ffffffff8121d2dd>] ? poll_freewait+0x8d/0xb0 [ 3945.385495] [<ffffffff81244520>] ? I_BDEV+0x20/0x20 [ 3945.385497] [<ffffffff81244e43>] blkdev_direct_IO+0x43/0x50 [ 3945.385500] [<ffffffff81179b04>] generic_file_direct_write+0xb4/0x170 [ 3945.385502] [<ffffffff81179c7b>] __generic_file_write_iter+0xbb/0x1d0 [ 3945.385504] [<ffffffff81205d34>] ? __check_object_size+0x54/0x1d6 [ 3945.385506] [<ffffffff81245fb0>] ? bd_acquire+0xb0/0xb0 [ 3945.385508] [<ffffffff8124603b>] blkdev_write_iter+0x8b/0x100 [ 3945.385509] [<ffffffff81245fb0>] ? bd_acquire+0xb0/0xb0 [ 3945.385511] [<ffffffff8131235a>] ? import_iovec+0x3a/0xe0 [ 3945.385514] [<ffffffff81259407>] aio_run_iocb+0x247/0x2c0 [ 3945.385516] [<ffffffff81256586>] ? eventfd_ctx_read+0x166/0x1e0 [ 3945.385518] [<ffffffff8121d4c0>] ? poll_select_copy_remaining+0x150/0x150 [ 3945.385519] [<ffffffff810a6c00>] ? wake_up_q+0x80/0x80 [ 3945.385521] [<ffffffff81227567>] ? __fget+0x77/0xb0 [ 3945.385522] [<ffffffff81227605>] ? __fget_light+0x25/0x60 [ 3945.385524] [<ffffffff81227653>] ? __fdget+0x13/0x20 [ 3945.385526] [<ffffffff8125ade4>] do_io_submit+0x364/0x590 [ 3945.385528] [<ffffffff8125b020>] SyS_io_submit+0x10/0x20 [ 3945.385530] [<ffffffff815f8032>] entry_SYSCALL_64_fastpath+0x1a/0xa4 [ 4068.241562] INFO: task kworker/22:0:146 blocked for more than 120 seconds. [ 4068.243485] Not tainted 4.8.13-1-ARCH #1 [ 4068.245395] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 4068.247346] kworker/22:0 D ffff88046d2c3cd8 0 146 2 0x00000000 [ 4068.247354] Workqueue: events update_writeback_rate [bcache] [ 4068.247355] ffff88046d2c3cd8 00ff88046d2c3cd0 ffff88046148e3c0 ffff88046d270e40 [ 4068.247358] ffff88046fd97ff0 ffff88046d2c4000 ffff8804696f0ad8 ffff88046d2c3d10 [ 4068.247360] ffff8804696f0af0 ffff8804696f0b18 ffff88046d2c3cf0 ffffffff815f40ec [ 4068.247406] Call Trace: [ 4068.247409] [<ffffffff815f40ec>] schedule+0x3c/0x90 [ 4068.247411] [<ffffffff815f6669>] rwsem_down_read_failed+0xf9/0x150 [ 4068.247413] [<ffffffff8130bb08>] call_rwsem_down_read_failed+0x18/0x30 [ 4068.247415] [<ffffffff815f5f07>] down_read+0x17/0x30 [ 4068.247418] [<ffffffffa0056dc5>] update_writeback_rate+0x25/0x210 [bcache] [ 4068.247421] [<ffffffff81095ef5>] process_one_work+0x1e5/0x470 [ 4068.247422] [<ffffffff810961c8>] worker_thread+0x48/0x4e0 [ 4068.247424] [<ffffffff81096180>] ? process_one_work+0x470/0x470 [ 4068.247426] [<ffffffff8109be38>] kthread+0xd8/0xf0 [ 4068.247427] [<ffffffff8102c782>] ? __switch_to+0x2d2/0x630 [ 4068.247429] [<ffffffff815f823f>] ret_from_fork+0x1f/0x40 [ 4068.247432] [<ffffffff8109bd60>] ? kthread_worker_fn+0x170/0x170 [ 4068.247439] INFO: task bcache_writebac:343 blocked for more than 120 seconds. [ 4068.249394] Not tainted 4.8.13-1-ARCH #1 [ 4068.251285] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 4068.253194] bcache_writebac D ffff88046975fcb8 0 343 2 0x00000000 [ 4068.253196] ffff88046975fcb8 00ff88046fa17f80 ffffffff81a0d500 ffff88046978d580 [ 4068.253199] ffff88046978d500 ffff880469760000 ffff8804696f0ad8 ffff8804696f0ad8 [ 4068.253201] ffff8804696f0af0 ffffffff00000001 ffff88046975fcd0 ffffffff815f40ec [ 4068.253203] Call Trace: [ 4068.253205] [<ffffffff815f40ec>] schedule+0x3c/0x90 [ 4068.253207] [<ffffffff815f67f2>] rwsem_down_write_failed+0x132/0x2b0 [ 4068.253209] [<ffffffff8130bb37>] call_rwsem_down_write_failed+0x17/0x30 [ 4068.253211] [<ffffffff815f5f44>] down_write+0x24/0x40 [ 4068.253214] [<ffffffffa005747b>] bch_writeback_thread+0x6b/0x7f0 [bcache] [ 4068.253218] [<ffffffffa0057410>] ? write_dirty+0xb0/0xb0 [bcache] [ 4068.253220] [<ffffffff8109be38>] kthread+0xd8/0xf0 [ 4068.253221] [<ffffffff8102c782>] ? __switch_to+0x2d2/0x630 [ 4068.253223] [<ffffffff815f823f>] ret_from_fork+0x1f/0x40 [ 4068.253225] [<ffffffff8109bd60>] ? kthread_worker_fn+0x170/0x170 [ 4068.253230] INFO: task qemu-system-x86:829 blocked for more than 120 seconds. [ 4068.255137] Not tainted 4.8.13-1-ARCH #1 [ 4068.256969] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 4068.258844] qemu-system-x86 D ffff88046933b7a8 0 829 1 0x00000000 [ 4068.258846] ffff88046933b7a8 00ff88046933b7b0 ffff8808650faac0 ffff88086ab52ac0 [ 4068.258848] 8000000000000000 ffff88046933c000 ffff8804696f0ad8 ffff88046933b7e0 [ 4068.258850] ffff8804696f0af0 ffff8804696f0000 ffff88046933b7c0 ffffffff815f40ec [ 4068.258853] Call Trace: [ 4068.258855] [<ffffffff815f40ec>] schedule+0x3c/0x90 [ 4068.258856] [<ffffffff815f6669>] rwsem_down_read_failed+0xf9/0x150 [ 4068.258861] [<ffffffffa00457db>] ? bch_submit_bbio+0x2b/0x30 [bcache] [ 4068.258863] [<ffffffff8130bb08>] call_rwsem_down_read_failed+0x18/0x30 [ 4068.258866] [<ffffffff815f5f07>] down_read+0x17/0x30 [ 4068.258870] [<ffffffffa004ab9b>] cached_dev_make_request+0x63b/0xcb0 [bcache] [ 4068.258872] [<ffffffff812cd0e2>] generic_make_request+0xf2/0x1a0 [ 4068.258874] [<ffffffff812cd20d>] submit_bio+0x7d/0x150 [ 4068.258877] [<ffffffff8124a1e3>] __blockdev_direct_IO+0x31a3/0x4040 [ 4068.258879] [<ffffffff8121d2dd>] ? poll_freewait+0x8d/0xb0 [ 4068.258881] [<ffffffff81244520>] ? I_BDEV+0x20/0x20 [ 4068.258883] [<ffffffff81244e43>] blkdev_direct_IO+0x43/0x50 [ 4068.258886] [<ffffffff81179b04>] generic_file_direct_write+0xb4/0x170 [ 4068.258887] [<ffffffff81179c7b>] __generic_file_write_iter+0xbb/0x1d0 [ 4068.258889] [<ffffffff81205d34>] ? __check_object_size+0x54/0x1d6 [ 4068.258891] [<ffffffff81245fb0>] ? bd_acquire+0xb0/0xb0 [ 4068.258892] [<ffffffff8124603b>] blkdev_write_iter+0x8b/0x100 [ 4068.258894] [<ffffffff81245fb0>] ? bd_acquire+0xb0/0xb0 [ 4068.258896] [<ffffffff8131235a>] ? import_iovec+0x3a/0xe0 [ 4068.258898] [<ffffffff81259407>] aio_run_iocb+0x247/0x2c0 [ 4068.258900] [<ffffffff81256586>] ? eventfd_ctx_read+0x166/0x1e0 [ 4068.258901] [<ffffffff8121d4c0>] ? poll_select_copy_remaining+0x150/0x150 [ 4068.258903] [<ffffffff810a6c00>] ? wake_up_q+0x80/0x80 [ 4068.258904] [<ffffffff81227567>] ? __fget+0x77/0xb0 [ 4068.258906] [<ffffffff81227605>] ? __fget_light+0x25/0x60 [ 4068.258908] [<ffffffff81227653>] ? __fdget+0x13/0x20 [ 4068.258911] [<ffffffff8125ade4>] do_io_submit+0x364/0x590 [ 4068.258913] [<ffffffff8125b020>] SyS_io_submit+0x10/0x20 [ 4068.258915] [<ffffffff815f8032>] entry_SYSCALL_64_fastpath+0x1a/0xa4 [ 4068.258917] INFO: task qemu-system-x86:903 blocked for more than 120 seconds. [ 4068.260756] Not tainted 4.8.13-1-ARCH #1 [ 4068.262646] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 4068.264530] qemu-system-x86 D ffff8802966b77a8 0 903 1 0x00000000 [ 4068.264533] ffff8802966b77a8 00ff88086ab53900 ffff880460a1c740 ffff88086ab53900 [ 4068.264535] ffff8802966b77f8 ffff8802966b8000 ffff8804696f0ad8 ffff8802966b77e0 [ 4068.264537] ffff8804696f0af0 ffff8804696f0000 ffff8802966b77c0 ffffffff815f40ec [ 4068.264539] Call Trace: [ 4068.264541] [<ffffffff815f40ec>] schedule+0x3c/0x90 [ 4068.264543] [<ffffffff815f6669>] rwsem_down_read_failed+0xf9/0x150 [ 4068.264545] [<ffffffff8130bb08>] call_rwsem_down_read_failed+0x18/0x30 [ 4068.264546] [<ffffffff815f5f07>] down_read+0x17/0x30 [ 4068.264550] [<ffffffffa004ab9b>] cached_dev_make_request+0x63b/0xcb0 [bcache] [ 4068.264552] [<ffffffff812cd0e2>] generic_make_request+0xf2/0x1a0 [ 4068.264554] [<ffffffff812cd20d>] submit_bio+0x7d/0x150 [ 4068.264556] [<ffffffff8124a1e3>] __blockdev_direct_IO+0x31a3/0x4040 [ 4068.264558] [<ffffffff8121d2dd>] ? poll_freewait+0x8d/0xb0 [ 4068.264560] [<ffffffff81244520>] ? I_BDEV+0x20/0x20 [ 4068.264562] [<ffffffff81244e43>] blkdev_direct_IO+0x43/0x50 [ 4068.264564] [<ffffffff81179b04>] generic_file_direct_write+0xb4/0x170 [ 4068.264566] [<ffffffff81179c7b>] __generic_file_write_iter+0xbb/0x1d0 [ 4068.264567] [<ffffffff81205d34>] ? __check_object_size+0x54/0x1d6 [ 4068.264569] [<ffffffff81245fb0>] ? bd_acquire+0xb0/0xb0 [ 4068.264571] [<ffffffff8124603b>] blkdev_write_iter+0x8b/0x100 [ 4068.264573] [<ffffffff81245fb0>] ? bd_acquire+0xb0/0xb0 [ 4068.264574] [<ffffffff8131235a>] ? import_iovec+0x3a/0xe0 [ 4068.264576] [<ffffffff81259407>] aio_run_iocb+0x247/0x2c0 [ 4068.264579] [<ffffffff810af45c>] ? set_next_entity+0x4c/0x940 [ 4068.264581] [<ffffffff810b41d4>] ? put_prev_entity+0xb4/0x8c0 [ 4068.264582] [<ffffffff81227567>] ? __fget+0x77/0xb0 [ 4068.264583] [<ffffffff81227605>] ? __fget_light+0x25/0x60 [ 4068.264585] [<ffffffff81227653>] ? __fdget+0x13/0x20 [ 4068.264587] [<ffffffff8125ade4>] do_io_submit+0x364/0x590 [ 4068.264589] [<ffffffff8125b020>] SyS_io_submit+0x10/0x20 [ 4068.264590] [<ffffffff815f8032>] entry_SYSCALL_64_fastpath+0x1a/0xa4 -- To unsubscribe from this list: send the line "unsubscribe linux-bcache" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
