| Message ID | 20240405223556.11142-2-andrea.righi@canonical.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | BPF |
| Headers | show |
| Series | libbpf: API to partially consume items from ringbuffer | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Not a local patch |
| bpf/vmtest-bpf-next-VM_Test-2 | success | Logs for Unittests |
| bpf/vmtest-bpf-next-VM_Test-3 | success | Logs for Validate matrix.py |
| bpf/vmtest-bpf-next-VM_Test-1 | success | Logs for ShellCheck |
| bpf/vmtest-bpf-next-VM_Test-0 | success | Logs for Lint |
| bpf/vmtest-bpf-next-VM_Test-5 | success | Logs for aarch64-gcc / build-release |
| bpf/vmtest-bpf-next-PR | fail | PR summary |
| bpf/vmtest-bpf-next-VM_Test-4 | fail | Logs for aarch64-gcc / build / build for aarch64 with gcc |
| bpf/vmtest-bpf-next-VM_Test-6 | success | Logs for aarch64-gcc / test |
| bpf/vmtest-bpf-next-VM_Test-7 | success | Logs for aarch64-gcc / veristat |
| bpf/vmtest-bpf-next-VM_Test-9 | success | Logs for s390x-gcc / build-release |
| bpf/vmtest-bpf-next-VM_Test-10 | success | Logs for s390x-gcc / test |
| bpf/vmtest-bpf-next-VM_Test-8 | fail | Logs for s390x-gcc / build / build for s390x with gcc |
| bpf/vmtest-bpf-next-VM_Test-11 | success | Logs for s390x-gcc / veristat |
| bpf/vmtest-bpf-next-VM_Test-12 | success | Logs for set-matrix |
| bpf/vmtest-bpf-next-VM_Test-13 | fail | Logs for x86_64-gcc / build / build for x86_64 with gcc |
| bpf/vmtest-bpf-next-VM_Test-16 | success | Logs for x86_64-gcc / veristat |
| bpf/vmtest-bpf-next-VM_Test-15 | success | Logs for x86_64-gcc / test |
| bpf/vmtest-bpf-next-VM_Test-14 | success | Logs for x86_64-gcc / build-release |
| bpf/vmtest-bpf-next-VM_Test-17 | fail | Logs for x86_64-llvm-17 / build / build for x86_64 with llvm-17 |
| bpf/vmtest-bpf-next-VM_Test-20 | success | Logs for x86_64-llvm-17 / veristat |
| bpf/vmtest-bpf-next-VM_Test-18 | fail | Logs for x86_64-llvm-17 / build-release / build for x86_64 with llvm-17 and -O2 optimization |
| bpf/vmtest-bpf-next-VM_Test-19 | success | Logs for x86_64-llvm-17 / test |
| bpf/vmtest-bpf-next-VM_Test-22 | fail | Logs for x86_64-llvm-18 / build-release / build for x86_64 with llvm-18 and -O2 optimization |
| bpf/vmtest-bpf-next-VM_Test-23 | success | Logs for x86_64-llvm-18 / test |
| bpf/vmtest-bpf-next-VM_Test-21 | fail | Logs for x86_64-llvm-18 / build / build for x86_64 with llvm-18 |
| bpf/vmtest-bpf-next-VM_Test-24 | success | Logs for x86_64-llvm-18 / veristat |
diff --git a/tools/lib/bpf/ringbuf.c b/tools/lib/bpf/ringbuf.c index aacb64278a01..2c4031168413 100644 --- a/tools/lib/bpf/ringbuf.c +++ b/tools/lib/bpf/ringbuf.c @@ -231,7 +231,7 @@ static inline int roundup_len(__u32 len) return (len + 7) / 8 * 8; } -static int64_t ringbuf_process_ring(struct ring *r) +static int64_t ringbuf_process_ring(struct ring *r, size_t n) { int *len_ptr, len, err; /* 64-bit to avoid overflow in case of extreme application behavior */ @@ -268,6 +268,9 @@ static int64_t ringbuf_process_ring(struct ring *r) } smp_store_release(r->consumer_pos, cons_pos); + + if (cnt >= n) + goto done; } } while (got_new_data); done: @@ -287,13 +290,15 @@ int ring_buffer__consume(struct ring_buffer *rb) for (i = 0; i < rb->ring_cnt; i++) { struct ring *ring = rb->rings[i]; - err = ringbuf_process_ring(ring); + err = ringbuf_process_ring(ring, INT_MAX); if (err < 0) return libbpf_err(err); res += err; + if (res > INT_MAX) { + res = INT_MAX; + break; + } } - if (res > INT_MAX) - return INT_MAX; return res; } @@ -314,13 +319,15 @@ int ring_buffer__poll(struct ring_buffer *rb, int timeout_ms) __u32 ring_id = rb->events[i].data.fd; struct ring *ring = rb->rings[ring_id]; - err = ringbuf_process_ring(ring); + err = ringbuf_process_ring(ring, INT_MAX); if (err < 0) return libbpf_err(err); res += err; + if (res > INT_MAX) { + res = INT_MAX; + break; + } } - if (res > INT_MAX) - return INT_MAX; return res; } @@ -375,7 +382,7 @@ int ring__consume(struct ring *r) { int64_t res; - res = ringbuf_process_ring(r); + res = ringbuf_process_ring(r, INT_MAX); if (res < 0) return libbpf_err(res);
In some cases, instead of always consuming all items from ring buffers in a greedy way, we may want to consume up to a certain amount of items, for example when we need to copy items from the BPF ring buffer to a limited user buffer. This change allows to set an upper limit to the amount of items consumed from one or more ring buffers. Signed-off-by: Andrea Righi <andrea.righi@canonical.com> --- tools/lib/bpf/ringbuf.c | 23 +++++++++++++++-------- 1 file changed, 15 insertions(+), 8 deletions(-)