Suricata

[root@openstack-slave1 ~]# uname -r
3.10.0-123.el7.x86_64
[root@openstack-slave1 ~]# lsb_release -a
LSB Version:    :core-4.1-amd64:core-4.1-noarch:cxx-4.1-amd64:cxx-4.1-noarch:desktop-4.1-amd64:desktop-4.1-noarch:languages-4.1-amd64:languages-4.1-noarch:printing-4.1-amd64:printing-4.1-noarch
Distributor ID:    CentOS
Description:    CentOS Linux release 7.0.1406 (Core) 
Release:    7.0.1406
Codename:    Core
[root@openstack-slave1 ~]# ifconfig p6p2
p6p2: flags=4419<UP,BROADCAST,RUNNING,PROMISC,MULTICAST>  mtu 1500
        inet6 fe80::92e2:baff:fe1a:999d  prefixlen 64  scopeid 0x20<link>
        ether 90:e2:ba:1a:99:9d  txqueuelen 1000  (Ethernet)
        RX packets 15416951  bytes 8789526257 (8.1 GiB)
        RX errors 0  dropped 26456499  overruns 0  frame 0
        TX packets 8  bytes 648 (648.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

[root@openstack-slave1 ~]# ethtool -i p6p2
driver: ixgbe
version: 5.0.4
firmware-version: 0x18b30001
bus-info: 0000:04:00.1
supports-statistics: yes
supports-test: yes
supports-eeprom-access: yes
supports-register-dump: yes
supports-priv-flags: yes
[root@openstack-slave1 ~]# lsmod |grep netmap
netmap                144395  11 ixgbe

I debug suricata process
the stack is:

(gdb) info threads
  Id   Target Id         Frame 
  18   Thread 0x7f4a4f937700 (LWP 189545) "W#01-p6p2" 0x00007f4a5131de0d in poll () from /lib64/libc.so.6
  17   Thread 0x7f4a4f136700 (LWP 189547) "W#02-p6p2" 0x00007f4a51a7f705 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
  16   Thread 0x7f4a4e935700 (LWP 189548) "W#03-p6p2" 0x00007f4a51a7f705 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
  15   Thread 0x7f4a4e134700 (LWP 189549) "W#04-p6p2" 0x00007f4a51a7f705 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
  14   Thread 0x7f4a4d933700 (LWP 189550) "W#05-p6p2" 0x00007f4a51a7f705 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
  13   Thread 0x7f4a4d132700 (LWP 189551) "W#06-p6p2" 0x00007f4a51a7f705 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
  12   Thread 0x7f4a4c931700 (LWP 189552) "W#07-p6p2" 0x00007f4a51a7f705 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
  11   Thread 0x7f4a338de700 (LWP 189553) "W#08-p6p2" 0x00007f4a51a7f705 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
  10   Thread 0x7f4a330dd700 (LWP 189554) "W#09-p6p2" 0x00007f4a51a7f705 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
  9    Thread 0x7f4a328dc700 (LWP 189555) "W#10-p6p2" 0x00007f4a51a7f705 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
  8    Thread 0x7f4a320db700 (LWP 189556) "W#11-p6p2" 0x00007f4a51a7f705 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
  7    Thread 0x7f4a318da700 (LWP 189557) "W#12-p6p2" 0x00007f4a51a7f705 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
  6    Thread 0x7f4a310d9700 (LWP 189558) "FM#01" 0x00007f4a51a7fab2 in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
  5    Thread 0x7f4a308d8700 (LWP 189559) "FR#01" 0x00007f4a51a7fab2 in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
  4    Thread 0x7f49fbfff700 (LWP 189560) "CW" 0x00007f4a51a7fab2 in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
  3    Thread 0x7f49fb7fe700 (LWP 189561) "CS" 0x00007f4a51a7fab2 in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
  2    Thread 0x7f49faffd700 (LWP 189562) "US" 0x00007f4a5131fb63 in select () from /lib64/libc.so.6
* 1    Thread 0x7f4a52b3f900 (LWP 189542) "Suricata-Main" 0x00007f4a512ef8ad in nanosleep () from /lib64/libc.so.6

(gdb) thread 10
[Switching to thread 10 (Thread 0x7f4a330dd700 (LWP 189554))]
#0  0x00007f4a51a7f705 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
(gdb) bt
#0  0x00007f4a51a7f705 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
#1  0x00000000006815f9 in PacketPoolWaitForN (n=0) at tmqh-packetpool.c:208
#2  0x0000000000614087 in NetmapRingRead (ring_id=8, ntv=0x7f4a0c26c8c0) at source-netmap.c:750
#3  ReceiveNetmapLoop (tv=0x38f75c0, data=0x7f4a0c26c8c0, slot=<optimized out>) at source-netmap.c:900
#4  0x0000000000686efa in TmThreadsSlotPktAcqLoop (td=0x38f75c0) at tm-threads.c:334
#5  0x00007f4a51a7bdf3 in start_thread () from /lib64/libpthread.so.0
#6  0x00007f4a513283dd in clone () from /lib64/libc.so.6

I found nm_ring_space() function return value is 0, the result is capture threads is locked.