On 03/17, Jesper Dangaard Brouer wrote:
When driver developers add XDP-hints kfuncs for RX hash it is
practical to print the return code in bpf_printk trace pipe log.
Print hash value as a hex value, both AF_XDP userspace and bpf_prog,
as this makes it easier to spot poor quality hashes.
Signed-off-by: Jesper Dangaard Brouer <brouer@xxxxxxxxxx>
Acked-by: Stanislav Fomichev <sdf@xxxxxxxxxx>
(with a small suggestion below, maybe can do separately?)
---
.../testing/selftests/bpf/progs/xdp_hw_metadata.c | 9 ++++++---
tools/testing/selftests/bpf/xdp_hw_metadata.c | 5 ++++-
2 files changed, 10 insertions(+), 4 deletions(-)
diff --git a/tools/testing/selftests/bpf/progs/xdp_hw_metadata.c
b/tools/testing/selftests/bpf/progs/xdp_hw_metadata.c
index f2a3b70a9882..f2278ca2ad03 100644
--- a/tools/testing/selftests/bpf/progs/xdp_hw_metadata.c
+++ b/tools/testing/selftests/bpf/progs/xdp_hw_metadata.c
@@ -76,10 +76,13 @@ int rx(struct xdp_md *ctx)
} else
meta->rx_timestamp = 0; /* Used by AF_XDP as not avail signal */
- if (!bpf_xdp_metadata_rx_hash(ctx, &meta->rx_hash))
- bpf_printk("populated rx_hash with %u", meta->rx_hash);
- else
+ ret = bpf_xdp_metadata_rx_hash(ctx, &meta->rx_hash);
+ if (ret >= 0) {
+ bpf_printk("populated rx_hash with 0x%08X", meta->rx_hash);
+ } else {
+ bpf_printk("rx_hash not-avail errno:%d", ret);
meta->rx_hash = 0; /* Used by AF_XDP as not avail signal */
+ }
return bpf_redirect_map(&xsk, ctx->rx_queue_index, XDP_PASS);
}
diff --git a/tools/testing/selftests/bpf/xdp_hw_metadata.c
b/tools/testing/selftests/bpf/xdp_hw_metadata.c
index 400bfe19abfe..f3ec07ccdc95 100644
--- a/tools/testing/selftests/bpf/xdp_hw_metadata.c
+++ b/tools/testing/selftests/bpf/xdp_hw_metadata.c
@@ -3,6 +3,9 @@
/* Reference program for verifying XDP metadata on real HW. Functional
test
* only, doesn't test the performance.
*
[..]
+ * BPF-prog bpf_printk info outout can be access via
+ * /sys/kernel/debug/tracing/trace_pipe
Maybe we should just dump the contents of
/sys/kernel/debug/tracing/trace for every poll cycle?
We can also maybe enable tracing in this program transparently?
I usually forget 'echo 1 >
/sys/kernel/debug/tracing/events/bpf_trace/bpf_trace_printk/enable'
myself :-)
+ *
* RX:
* - UDP 9091 packets are diverted into AF_XDP
* - Metadata verified:
@@ -156,7 +159,7 @@ static void verify_xdp_metadata(void *data, clockid_t
clock_id)
meta = data - sizeof(*meta);
- printf("rx_hash: %u\n", meta->rx_hash);
+ printf("rx_hash: 0x%08X\n", meta->rx_hash);
printf("rx_timestamp: %llu (sec:%0.4f)\n", meta->rx_timestamp,
(double)meta->rx_timestamp / NANOSEC_PER_SEC);
if (meta->rx_timestamp) {
