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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /tools/testing/selftests/bpf/progs/test_ringbuf.c | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tools/testing/selftests/bpf/progs/test_ringbuf.c')
-rw-r--r-- | tools/testing/selftests/bpf/progs/test_ringbuf.c | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/test_ringbuf.c b/tools/testing/selftests/bpf/progs/test_ringbuf.c new file mode 100644 index 000000000..8ba9959b0 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_ringbuf.c @@ -0,0 +1,78 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2020 Facebook + +#include <linux/bpf.h> +#include <bpf/bpf_helpers.h> + +char _license[] SEC("license") = "GPL"; + +struct sample { + int pid; + int seq; + long value; + char comm[16]; +}; + +struct { + __uint(type, BPF_MAP_TYPE_RINGBUF); + __uint(max_entries, 1 << 12); +} ringbuf SEC(".maps"); + +/* inputs */ +int pid = 0; +long value = 0; +long flags = 0; + +/* outputs */ +long total = 0; +long discarded = 0; +long dropped = 0; + +long avail_data = 0; +long ring_size = 0; +long cons_pos = 0; +long prod_pos = 0; + +/* inner state */ +long seq = 0; + +SEC("tp/syscalls/sys_enter_getpgid") +int test_ringbuf(void *ctx) +{ + int cur_pid = bpf_get_current_pid_tgid() >> 32; + struct sample *sample; + int zero = 0; + + if (cur_pid != pid) + return 0; + + sample = bpf_ringbuf_reserve(&ringbuf, sizeof(*sample), 0); + if (!sample) { + __sync_fetch_and_add(&dropped, 1); + return 1; + } + + sample->pid = pid; + bpf_get_current_comm(sample->comm, sizeof(sample->comm)); + sample->value = value; + + sample->seq = seq++; + __sync_fetch_and_add(&total, 1); + + if (sample->seq & 1) { + /* copy from reserved sample to a new one... */ + bpf_ringbuf_output(&ringbuf, sample, sizeof(*sample), flags); + /* ...and then discard reserved sample */ + bpf_ringbuf_discard(sample, flags); + __sync_fetch_and_add(&discarded, 1); + } else { + bpf_ringbuf_submit(sample, flags); + } + + avail_data = bpf_ringbuf_query(&ringbuf, BPF_RB_AVAIL_DATA); + ring_size = bpf_ringbuf_query(&ringbuf, BPF_RB_RING_SIZE); + cons_pos = bpf_ringbuf_query(&ringbuf, BPF_RB_CONS_POS); + prod_pos = bpf_ringbuf_query(&ringbuf, BPF_RB_PROD_POS); + + return 0; +} |