[root@tos-perf4 zfs_debug]# ps -ef |grep zfs
root     11402 29978  0 14:22 pts/2    00:00:00 zfs list
root     18478 16521  0 15:08 pts/3    00:00:00 grep --color=auto zfs
root     27963 27920  0 12:44 ?        00:00:00 zfs receive flocker-silver/5564c527-6028-4fcd-87fd-58b25453d190.default.82872f21-c667-44ef-a620-757edb09583b
root     27966 16368  0 12:44 ?        00:00:00 zfs rename flocker-silver/af1addb3-46af-4291-af24-dd8973a592e2.default.37565b70-33da-4cee-a1a1-e13c00ea02fe flocker-silver/5a178e58-0fd2-403a-b9a1-2b4a4d075c5e.default.37565b70-33da-4cee-a1a1-e13c00ea02fe
root     27995 15601  0 12:44 ?        00:00:00 zfs get -Hp all flocker-silver/af1addb3-46af-4291-af24-dd8973a592e2.default.6ca0988a-7b1f-4b52-a7ef-518a15f8b607
root     28406 16511  0 12:47 pts/0    00:00:00 zfs list
root     29641 25624  0 12:55 pts/1    00:00:00 zfs list


[root@tos-perf4 zfs_debug]# cat /proc/27963/stack 
[<ffffffffa031d775>] cv_wait_common+0x125/0x150 [spl]
[<ffffffffa031d7b5>] __cv_wait+0x15/0x20 [spl]
[<ffffffffa0568353>] rrw_enter_read_impl+0x53/0x170 [zfs]
[<ffffffffa0568660>] rrw_enter+0x20/0x30 [zfs]
[<ffffffffa0557bca>] dsl_pool_hold+0x5a/0x80 [zfs]
[<ffffffffa0532b95>] dmu_objset_hold+0x35/0xd0 [zfs]
[<ffffffffa0558364>] dsl_prop_get+0x44/0xa0 [zfs]
[<ffffffffa05583de>] dsl_prop_get_integer+0x1e/0x20 [zfs]
[<ffffffffa05da9fd>] __zvol_create_minor+0xbd/0x640 [zfs]
[<ffffffffa05db803>] zvol_create_minor+0x33/0x70 [zfs]
[<ffffffffa05db84e>] zvol_create_minors_cb+0xe/0x20 [zfs]
[<ffffffffa0534665>] dmu_objset_find_impl+0x3a5/0x430 [zfs]
[<ffffffffa0534748>] dmu_objset_find+0x58/0x90 [zfs]
[<ffffffffa05db9ef>] zvol_create_minors+0x2f/0x40 [zfs]
[<ffffffffa05aeb52>] zfs_ioc_recv+0x3a2/0xbf0 [zfs]
[<ffffffffa05ad63d>] zfsdev_ioctl+0x4bd/0x500 [zfs]
[<ffffffff811f1f55>] do_vfs_ioctl+0x2e5/0x4c0
[<ffffffff811f21d1>] SyS_ioctl+0xa1/0xc0
[<ffffffff81645a49>] system_call_fastpath+0x16/0x1b
[<ffffffffffffffff>] 0xffffffffffffffff
[root@tos-perf4 zfs_debug]# cat /proc/27966/stack                                                                                                                                                                                                                       
[<ffffffffa031d775>] cv_wait_common+0x125/0x150 [spl]
[<ffffffffa031d7b5>] __cv_wait+0x15/0x20 [spl]
[<ffffffffa058367f>] txg_wait_synced+0xef/0x140 [zfs]
[<ffffffffa055ec37>] dsl_sync_task+0x177/0x270 [zfs]
[<ffffffffa055406b>] dsl_dir_rename+0x5b/0x80 [zfs]
[<ffffffffa05a8ec7>] zfs_ioc_rename+0x107/0x110 [zfs]
[<ffffffffa05ad63d>] zfsdev_ioctl+0x4bd/0x500 [zfs]
[<ffffffff811f1f55>] do_vfs_ioctl+0x2e5/0x4c0
[<ffffffff811f21d1>] SyS_ioctl+0xa1/0xc0
[<ffffffff81645a49>] system_call_fastpath+0x16/0x1b
[<ffffffffffffffff>] 0xffffffffffffffff
[root@tos-perf4 zfs_debug]# cat /proc/27995/stack 
[<ffffffffa031d775>] cv_wait_common+0x125/0x150 [spl]
[<ffffffffa031d7b5>] __cv_wait+0x15/0x20 [spl]
[<ffffffffa0568353>] rrw_enter_read_impl+0x53/0x170 [zfs]
[<ffffffffa0568660>] rrw_enter+0x20/0x30 [zfs]
[<ffffffffa0557bca>] dsl_pool_hold+0x5a/0x80 [zfs]
[<ffffffffa0532b95>] dmu_objset_hold+0x35/0xd0 [zfs]
[<ffffffffa05a96c0>] zfs_ioc_objset_stats+0x30/0x80 [zfs]
[<ffffffffa05ad63d>] zfsdev_ioctl+0x4bd/0x500 [zfs]
[<ffffffff811f1f55>] do_vfs_ioctl+0x2e5/0x4c0
[<ffffffff811f21d1>] SyS_ioctl+0xa1/0xc0
[<ffffffff81645a49>] system_call_fastpath+0x16/0x1b
[<ffffffffffffffff>] 0xffffffffffffffff
[root@tos-perf4 zfs_debug]# cat /proc/28406/stack                                                                                                                                                                                                                       
[<ffffffffa031d775>] cv_wait_common+0x125/0x150 [spl]
[<ffffffffa031d7b5>] __cv_wait+0x15/0x20 [spl]
[<ffffffffa0568353>] rrw_enter_read_impl+0x53/0x170 [zfs]
[<ffffffffa0568660>] rrw_enter+0x20/0x30 [zfs]
[<ffffffffa0557bca>] dsl_pool_hold+0x5a/0x80 [zfs]
[<ffffffffa0532b95>] dmu_objset_hold+0x35/0xd0 [zfs]
[<ffffffffa05a96c0>] zfs_ioc_objset_stats+0x30/0x80 [zfs]
[<ffffffffa05ad63d>] zfsdev_ioctl+0x4bd/0x500 [zfs]
[<ffffffff811f1f55>] do_vfs_ioctl+0x2e5/0x4c0
[<ffffffff811f21d1>] SyS_ioctl+0xa1/0xc0
[<ffffffff81645a49>] system_call_fastpath+0x16/0x1b
[<ffffffffffffffff>] 0xffffffffffffffff