home-directory style - median is about 3KB - but varies greatly. I also get this: [41204.865818] INFO: task kworker/u16:102:21903 blocked for more than 120 seconds. [41204.865955] Not tainted 5.4.30 #5 [41204.866006] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [41204.866056] kworker/u16:102 D 0 21903 2 0x80004000 [41204.866119] Workqueue: ceph-inode ceph_inode_work [ceph] [41204.866120] Call Trace: [41204.866156] __schedule+0x45f/0x710 [41204.866162] ? xas_store+0x391/0x5f0 [41204.866164] schedule+0x3e/0xa0 [41204.866166] io_schedule+0x16/0x40 [41204.866180] __lock_page+0x12a/0x1d0 [41204.866182] ? file_fdatawait_range+0x30/0x30 [41204.866187] truncate_inode_pages_range+0x52c/0x980 [41204.866191] ? syscall_return_via_sysret+0x12/0x7f [41204.866197] ? drop_inode_snap_realm+0x98/0xa0 [ceph] [41204.866207] ? fsnotify_grab_connector+0x4d/0x90 [41204.866209] truncate_inode_pages_final+0x4c/0x60 [41204.866214] ceph_evict_inode+0x2d/0x210 [ceph] [41204.866219] evict+0xca/0x1a0 [41204.866221] iput+0x1ba/0x210 [41204.866225] ceph_inode_work+0x40/0x270 [ceph] [41204.866232] process_one_work+0x167/0x400 [41204.866233] worker_thread+0x4d/0x460 [41204.866236] kthread+0x105/0x140 [41204.866237] ? rescuer_thread+0x370/0x370 [41204.866239] ? kthread_destroy_worker+0x50/0x50 [41204.866240] ret_from_fork+0x35/0x40 On Mon, Apr 6, 2020 at 10:53 AM Yan, Zheng <ukernel@xxxxxxxxx> wrote: > > On Mon, Apr 6, 2020 at 4:06 PM Jesper Krogh <jesper.krogh@xxxxxxxxx> wrote: > > > > This is a CephFS client - its only purpose is to run the "filedaemon" of bacula > > and transport data to the tape-library from CephFS - below 2 threads is > > essentially doing something equivalent to > > > > find /cephfs/ -type f | xargs cat | nc server > > > > 2 threads only, load exploding and the "net read vs net write" has > > more than 100x difference. > > > > Can anyone explain this as "normal" behaviour? > > Server is a VM with 16 "vCPU" and 16GB memory running libvirt/qemu > > > > jk@wombat:~$ w > > 07:50:33 up 11:25, 1 user, load average: 206.43, 76.23, 50.58 > > USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT > > jk pts/0 10.194.133.42 06:54 0.00s 0.05s 0.00s w > > jk@wombat:~$ dstat -ar > > --total-cpu-usage-- -dsk/total- -net/total- ---paging-- ---system-- --io/total- > > usr sys idl wai stl| read writ| recv send| in out | int csw | read writ > > 0 0 98 1 0| 14k 34k| 0 0 | 3B 27B| 481 294 |0.55 0.73 > > 1 1 0 98 0| 0 0 | 60M 220k| 0 0 |6402 6182 | 0 0 > > 0 1 0 98 0| 0 0 | 69M 255k| 0 0 |7305 4339 | 0 0 > > 1 2 0 98 0| 0 0 | 76M 282k| 0 0 |7914 4886 | 0 0 > > 1 1 0 99 0| 0 0 | 70M 260k| 0 0 |7293 4444 | 0 0 > > 1 1 0 98 0| 0 0 | 80M 278k| 0 0 |8018 4931 | 0 0 > > 0 1 0 98 0| 0 0 | 60M 221k| 0 0 |6435 5951 | 0 0 > > 0 1 0 99 0| 0 0 | 59M 211k| 0 0 |6163 3584 | 0 0 > > 0 1 0 98 0| 0 0 | 64M 323k| 0 0 |6653 3881 | 0 0 > > 1 0 0 99 0| 0 0 | 61M 243k| 0 0 |6822 4401 | 0 0 > > 0 1 0 99 0| 0 0 | 55M 205k| 0 0 |5975 3518 | 0 0 > > 1 1 0 98 0| 0 0 | 68M 242k| 0 0 |7094 6544 | 0 0 > > 0 1 0 99 0| 0 0 | 58M 230k| 0 0 |6639 4178 | 0 0 > > 1 2 0 98 0| 0 0 | 61M 243k| 0 0 |7117 4477 | 0 0 > > 0 1 0 99 0| 0 0 | 61M 228k| 0 0 |6500 4078 | 0 0 > > 0 1 0 99 0| 0 0 | 65M 234k| 0 0 |6595 3914 | 0 0 > > 0 1 0 98 0| 0 0 | 64M 219k| 0 0 |6507 5755 | 0 0 > > 1 1 0 99 0| 0 0 | 64M 233k| 0 0 |6869 4153 | 0 0 > > 1 2 0 98 0| 0 0 | 63M 232k| 0 0 |6632 3907 | > > 0 0 ^C > > jk@wombat:~$ w > > 07:50:56 up 11:25, 1 user, load average: 221.35, 88.07, 55.02 > > USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT > > jk pts/0 10.194.133.42 06:54 0.00s 0.05s 0.00s w > > jk@wombat:~$ > > > > Thanks. > > how small these files are?
