Hi, on one of my OSDs the ceph-osd task hung for more than 120 sec. The OSD had almost no load, therefore it cannot be an overload problem. I think it is a btrfs problem, could someone clarify it? This was in the dmesg. [29280.890040] INFO: task btrfs-cleaner:1708 blocked for more than 120 seconds. [29280.905659] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [29280.922916] btrfs-cleaner D ffff8801153bdf80 0 1708 2 0x00000000 [29280.922931] ffff88011698bbd0 0000000000000046 ffff88011698bb90 ffffffff81090d7d [29280.922960] ffff880100000000 ffff88011698bfd8 ffff88011698a000 ffff88011698bfd8 [29280.922988] ffffffff81a0d020 ffff8801153bdbc0 ffff88011698bbd0 0000000181090d7d [29280.923018] Call Trace: [29280.923043] [<ffffffff81090d7d>] ? ktime_get_ts+0xad/0xe0 [29280.923062] [<ffffffff8110cf10>] ? __lock_page+0x70/0x70 [29280.923082] [<ffffffff815d93df>] schedule+0x3f/0x60 [29280.923098] [<ffffffff815d948c>] io_schedule+0x8c/0xd0 [29280.923114] [<ffffffff8110cf1e>] sleep_on_page+0xe/0x20 [29280.923130] [<ffffffff815d9c6f>] __wait_on_bit+0x5f/0x90 [29280.923147] [<ffffffff8110d168>] wait_on_page_bit+0x78/0x80 [29280.923165] [<ffffffff81086bd0>] ? autoremove_wake_function+0x40/0x40 [29280.923227] [<ffffffffa0065ecb>] btrfs_defrag_file+0x4fb/0xc10 [btrfs] [29280.923246] [<ffffffff8117f6ac>] ? find_inode+0xac/0xb0 [29280.923281] [<ffffffffa003a2d0>] ? btrfs_clean_old_snapshots+0x160/0x160 [btrfs] [29280.923302] [<ffffffff812e369b>] ? radix_tree_lookup+0xb/0x10 [29280.923337] [<ffffffffa0034f62>] ? btrfs_read_fs_root_no_name+0x1c2/0x2e0 [btrfs] [29280.923375] [<ffffffffa004897e>] btrfs_run_defrag_inodes+0x15e/0x210 [btrfs] [29280.923410] [<ffffffffa003278f>] cleaner_kthread+0x17f/0x1a0 [btrfs] [29280.923443] [<ffffffffa0032610>] ? btrfs_congested_fn+0xb0/0xb0 [btrfs] [29280.923460] [<ffffffff81086436>] kthread+0x96/0xa0 [29280.923477] [<ffffffff815e5934>] kernel_thread_helper+0x4/0x10 [29280.923493] [<ffffffff810863a0>] ? flush_kthread_worker+0xb0/0xb0 [29280.923510] [<ffffffff815e5930>] ? gs_change+0x13/0x13 [29280.923521] INFO: task btrfs-transacti:1709 blocked for more than 120 seconds. [29280.939551] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [29280.956782] btrfs-transacti D ffff880115745f80 0 1709 2 0x00000000 [29280.956792] ffff880115e6fd50 0000000000000046 ffff880115e6fd20 ffff880111a5a3e0 [29280.956800] ffff880100000000 ffff880115e6ffd8 ffff880115e6e000 ffff880115e6ffd8 [29280.956809] ffffffff81a0d020 ffff880115745bc0 0000000000000282 0000000116758450 [29280.956817] Call Trace: [29280.956827] [<ffffffff815d93df>] schedule+0x3f/0x60 [29280.956855] [<ffffffffa0037de5>] wait_for_commit.clone.16+0x55/0x90 [btrfs] [29280.956864] [<ffffffff81086b90>] ? wake_up_bit+0x40/0x40 [29280.956891] [<ffffffffa0039726>] btrfs_commit_transaction+0x776/0x860 [btrfs] [29280.956900] [<ffffffff8115653c>] ? kmem_cache_alloc+0x3c/0x130 [29280.956907] [<ffffffff815db6fe>] ? _raw_spin_lock+0xe/0x20 [29280.956933] [<ffffffffa003879d>] ? join_transaction.clone.24+0x5d/0x240 [btrfs] [29280.956941] [<ffffffff81086b90>] ? wake_up_bit+0x40/0x40 [29280.956966] [<ffffffffa0033323>] transaction_kthread+0x273/0x290 [btrfs] [29280.956991] [<ffffffffa00330b0>] ? check_leaf.clone.68+0x320/0x320 [btrfs] [29280.956999] [<ffffffff81086436>] kthread+0x96/0xa0 [29280.957007] [<ffffffff815e5934>] kernel_thread_helper+0x4/0x10 [29280.957015] [<ffffffff810863a0>] ? flush_kthread_worker+0xb0/0xb0 [29280.957022] [<ffffffff815e5930>] ? gs_change+0x13/0x13 [29280.957030] INFO: task ceph-osd:1855 blocked for more than 120 seconds. [29280.971860] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [29280.989164] ceph-osd D ffff880114865f80 0 1855 1 0x00000004 [29280.989173] ffff880115229c48 0000000000000082 ffff880115229bf8 ffff880115230fb8 [29280.989181] ffff880115229c00 ffff880115229fd8 ffff880115228000 ffff880115229fd8 [29280.989189] ffff8801151744d0 ffff880114865bc0 0000000000000282 ffff880117864208 [29280.989209] Call Trace: [29280.989226] [<ffffffff815d93df>] schedule+0x3f/0x60 [29280.989263] [<ffffffffa003a017>] btrfs_commit_transaction_async+0x1f7/0x270 [btrfs] [29280.989296] [<ffffffffa002375b>] ? block_rsv_add_bytes+0x5b/0x80 [btrfs] [29280.989314] [<ffffffff81086b90>] ? wake_up_bit+0x40/0x40 [29280.989344] [<ffffffffa00237ba>] ? block_rsv_migrate_bytes+0x3a/0x50 [btrfs] [29280.989380] [<ffffffffa00655b1>] btrfs_mksubvol+0x301/0x3a0 [btrfs] [29280.989416] [<ffffffffa0065750>] btrfs_ioctl_snap_create_transid+0x100/0x160 [btrfs] [29280.989453] [<ffffffffa00658d2>] btrfs_ioctl_snap_create_v2.clone.57+0xa2/0x100 [btrfs] [29280.989491] [<ffffffffa0066d5d>] btrfs_ioctl+0x1fd/0xe20 [btrfs] [29280.989507] [<ffffffff811657c2>] ? do_sync_write+0xd2/0x110 [29280.989525] [<ffffffff811a053d>] ? fsnotify+0x1cd/0x2e0 [29280.989541] [<ffffffff811779f8>] do_vfs_ioctl+0x98/0x540 [29280.989557] [<ffffffff81177f31>] sys_ioctl+0x91/0xa0 [29280.989575] [<ffffffff815e37c2>] system_call_fastpath+0x16/0x1b Best Regards, marti -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html