bpf: create samples/bpf/tcp_bpf.readme

Readme file explaining how to create a cgroupv2 and attach one
of the tcp_*_kern.o socket_ops BPF program.

Signed-off-by: Lawrence Brakmo <brakmo@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked_by: Alexei Starovoitov <ast@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Lawrence Brakmo 2017-10-20 11:05:43 -07:00 committed by David S. Miller
parent c890063e44
commit bfdf756938

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This file describes how to run the tcp_*_kern.o tcp_bpf (or socket_ops)
programs. These programs attach to a cgroupv2. The following commands create
a cgroupv2 and attach a bash shell to the group.
mkdir -p /tmp/cgroupv2
mount -t cgroup2 none /tmp/cgroupv2
mkdir -p /tmp/cgroupv2/foo
bash
echo $$ >> /tmp/cgroupv2/foo/cgroup.procs
Anything that runs under this shell belongs to the foo cgroupv2 To load
(attach) one of the tcp_*_kern.o programs:
./load_sock_ops -l /tmp/cgroupv2/foo tcp_basertt_kern.o
If the "-l" flag is used, the load_sock_ops program will continue to run
printing the BPF log buffer. The tcp_*_kern.o programs use special print
functions to print logging information (if enabled by the ifdef).
If using netperf/netserver to create traffic, you need to run them under the
cgroupv2 to which the BPF programs are attached (i.e. under bash shell
attached to the cgroupv2).
To remove (unattach) a socket_ops BPF program from a cgroupv2:
./load_sock_ops -r /tmp/cgroupv2/foo