| Lawrence Brakmo | bfdf756 | 2017-10-20 11:05:43 -0700 | [diff] [blame] | 1 | This file describes how to run the tcp_*_kern.o tcp_bpf (or socket_ops) |
| 2 | programs. These programs attach to a cgroupv2. The following commands create |
| 3 | a cgroupv2 and attach a bash shell to the group. |
| 4 | |
| 5 | mkdir -p /tmp/cgroupv2 |
| 6 | mount -t cgroup2 none /tmp/cgroupv2 |
| 7 | mkdir -p /tmp/cgroupv2/foo |
| 8 | bash |
| 9 | echo $$ >> /tmp/cgroupv2/foo/cgroup.procs |
| 10 | |
| Jakub Kicinski | ea9b636 | 2019-02-27 19:04:11 -0800 | [diff] [blame] | 11 | Anything that runs under this shell belongs to the foo cgroupv2. To load |
| Lawrence Brakmo | bfdf756 | 2017-10-20 11:05:43 -0700 | [diff] [blame] | 12 | (attach) one of the tcp_*_kern.o programs: |
| 13 | |
| Jakub Kicinski | ea9b636 | 2019-02-27 19:04:11 -0800 | [diff] [blame] | 14 | bpftool prog load tcp_basertt_kern.o /sys/fs/bpf/tcp_prog |
| 15 | bpftool cgroup attach /tmp/cgroupv2/foo sock_ops pinned /sys/fs/bpf/tcp_prog |
| 16 | bpftool prog tracelog |
| Lawrence Brakmo | bfdf756 | 2017-10-20 11:05:43 -0700 | [diff] [blame] | 17 | |
| Jakub Kicinski | ea9b636 | 2019-02-27 19:04:11 -0800 | [diff] [blame] | 18 | "bpftool prog tracelog" will continue to run printing the BPF log buffer. |
| 19 | The tcp_*_kern.o programs use special print functions to print logging |
| 20 | information (if enabled by the ifdef). |
| Lawrence Brakmo | bfdf756 | 2017-10-20 11:05:43 -0700 | [diff] [blame] | 21 | |
| 22 | If using netperf/netserver to create traffic, you need to run them under the |
| 23 | cgroupv2 to which the BPF programs are attached (i.e. under bash shell |
| 24 | attached to the cgroupv2). |
| 25 | |
| 26 | To remove (unattach) a socket_ops BPF program from a cgroupv2: |
| 27 | |
| Stanislav Fomichev | d78e3f0 | 2019-07-02 09:14:03 -0700 | [diff] [blame] | 28 | bpftool cgroup detach /tmp/cgroupv2/foo sock_ops pinned /sys/fs/bpf/tcp_prog |