| Network classifier cgroup | |
| ------------------------- | |
| The Network classifier cgroup provides an interface to | |
| tag network packets with a class identifier (classid). | |
| The Traffic Controller (tc) can be used to assign | |
| different priorities to packets from different cgroups. | |
| Creating a net_cls cgroups instance creates a net_cls.classid file. | |
| This net_cls.classid value is initialized to 0. | |
| You can write hexadecimal values to net_cls.classid; the format for these | |
| values is 0xAAAABBBB; AAAA is the major handle number and BBBB | |
| is the minor handle number. | |
| Reading net_cls.classid yields a decimal result. | |
| Example: | |
| mkdir /sys/fs/cgroup/net_cls | |
| mount -t cgroup -onet_cls net_cls /sys/fs/cgroup/net_cls | |
| mkdir /sys/fs/cgroup/net_cls/0 | |
| echo 0x100001 > /sys/fs/cgroup/net_cls/0/net_cls.classid | |
| - setting a 10:1 handle. | |
| cat /sys/fs/cgroup/net_cls/0/net_cls.classid | |
| 1048577 | |
| configuring tc: | |
| tc qdisc add dev eth0 root handle 10: htb | |
| tc class add dev eth0 parent 10: classid 10:1 htb rate 40mbit | |
| - creating traffic class 10:1 | |
| tc filter add dev eth0 parent 10: protocol ip prio 10 handle 1: cgroup |