linux-dev - Linux kernel development work

Age	Commit message (Collapse)	Author	Files	Lines
2021-07-27	bpf: Increase supported cgroup storage value size	Stanislav Fomichev	1	-9/+29
	Current max cgroup storage value size is 4k (PAGE_SIZE). The other local storages accept up to 64k (BPF_LOCAL_STORAGE_MAX_VALUE_SIZE). Let's align max cgroup value size with the other storages. For percpu, the max is 32k (PCPU_MIN_UNIT_SIZE) because percpu allocator is not happy about larger values. netcnt test is extended to exercise those maximum values (non-percpu max size is close to, but not real max). v4: * remove inner union (Andrii Nakryiko) * keep net_cnt on the stack (Andrii Nakryiko) v3: * refine SIZEOF_BPF_LOCAL_STORAGE_ELEM comment (Yonghong Song) * anonymous struct in percpu_net_cnt & net_cnt (Yonghong Song) * reorder free (Yonghong Song) v2: * cap max_value_size instead of BUILD_BUG_ON (Martin KaFai Lau) Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20210727222335.4029096-1-sdf@google.com
2018-10-01	selftests/bpf: cgroup local storage-based network counters	Roman Gushchin	1	-0/+24
	This commit adds a bpf kselftest, which demonstrates how percpu and shared cgroup local storage can be used for efficient lookup-free network accounting. Cgroup local storage provides generic memory area with a very efficient lookup free access. To avoid expensive atomic operations for each packet, per-cpu cgroup local storage is used. Each packet is initially charged to a per-cpu counter, and only if the counter reaches certain value (32 in this case), the charge is moved into the global atomic counter. This allows to amortize atomic operations, keeping reasonable accuracy. The test also implements a naive network traffic throttling, mostly to demonstrate the possibility of bpf cgroup--based network bandwidth control. Expected output: ./test_netcnt test_netcnt:PASS Signed-off-by: Roman Gushchin <guro@fb.com> Acked-by: Song Liu <songliubraving@fb.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>