This implements the userspace binding for RingBuf.
Instead of streaming the samples as heap buffers, the process_ring
function takes a callback to which we pass the event's byte region,
roughly following [libbpf]'s API design. This avoids a copy and allows
marking the consumer pointer in a timely manner.
[libbpf]: https://github.com/libbpf/libbpf/blob/master/src/ringbuf.c
Additionally, integration tests are added to demonstrate the usage
of the new APIs and to ensure that they work end-to-end.
Co-authored-by: William Findlay <william@williamfindlay.com>
Co-authored-by: Tatsuyuki Ishi <ishitatsuyuki@gmail.com>
"integration tests" as defined by Cargo produce a binary per file in the
tests directory. This is really not what we want and has a number of
downsides, but the main one is binary size.
Before:
tamird@pc:~/src/aya$ cargo xtask build-integration-test | xargs ls -lah
Finished dev [unoptimized + debuginfo] target(s) in 0.05s
Running `target/debug/xtask build-integration-test`
Compiling integration-test v0.1.0 (/home/tamird/src/aya/test/integration-test)
Finished dev [unoptimized + debuginfo] target(s) in 0.68s
-rwxrwxr-x 1 tamird tamird 34M Jul 12 15:21 /home/tamird/src/aya/target/debug/deps/bpf_probe_read-e03eb905a5e6209c
-rwxrwxr-x 1 tamird tamird 35M Jul 12 15:21 /home/tamird/src/aya/target/debug/deps/btf_relocations-57a4fbb38bf06064
-rwxrwxr-x 1 tamird tamird 31M Jul 12 15:21 /home/tamird/src/aya/target/debug/deps/elf-98b7a32d6d04effb
-rwxrwxr-x 1 tamird tamird 6.9M Jul 12 15:21 /home/tamird/src/aya/target/debug/deps/integration_test-0dd55ce96bfdad77
-rwxrwxr-x 1 tamird tamird 34M Jul 12 15:21 /home/tamird/src/aya/target/debug/deps/load-0718562e85b86d03
-rwxrwxr-x 1 tamird tamird 40M Jul 12 15:21 /home/tamird/src/aya/target/debug/deps/log-dbf355f9ea34068a
-rwxrwxr-x 1 tamird tamird 36M Jul 12 15:21 /home/tamird/src/aya/target/debug/deps/rbpf-89a1bb848fa5cc3c
-rwxrwxr-x 1 tamird tamird 34M Jul 12 15:21 /home/tamird/src/aya/target/debug/deps/relocations-cfe655c3bb413d8b
-rwxrwxr-x 1 tamird tamird 34M Jul 12 15:21 /home/tamird/src/aya/target/debug/deps/smoke-ccd3974180a3fd29
After:
tamird@pc:~/src/aya$ cargo xtask build-integration-test | xargs ls -lah
Finished dev [unoptimized + debuginfo] target(s) in 0.05s
Running `target/debug/xtask build-integration-test`
Compiling integration-test v0.1.0 (/home/tamird/src/aya/test/integration-test)
Finished dev [unoptimized + debuginfo] target(s) in 0.90s
-rwxrwxr-x 1 tamird tamird 47M Jul 12 15:21 /home/tamird/src/aya/target/debug/deps/integration_test-0dd55ce96bfdad77
Since we plan to run these tests in a VM, copying 10x fewer bytes seems
like a win.
Andrew Werner
Tuetuopay
Tamir Duberstein