Currently, libbpf uses the number of combined channels as the maximum
queue number. However, the kernel has a different limitation:
- xdp_reg_umem_at_qid() allows up to max(RX queues, TX queues).
- ethtool_set_channels() checks for UMEMs in queues up to
combined_count + max(rx_count, tx_count).
libbpf shouldn't limit applications to a lower max queue number. Account
for non-combined RX and TX channels when calculating the max queue
number. Use the same formula that is used in ethtool.
Signed-off-by: Maxim Mikityanskiy <maxi...@mellanox.com>
Reviewed-by: Tariq Toukan <tar...@mellanox.com>
Acked-by: Saeed Mahameed <sae...@mellanox.com>
---
tools/lib/bpf/xsk.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/tools/lib/bpf/xsk.c b/tools/lib/bpf/xsk.c
index bf15a80a37c2..86107857e1f0 100644
--- a/tools/lib/bpf/xsk.c
+++ b/tools/lib/bpf/xsk.c
@@ -334,13 +334,13 @@ static int xsk_get_max_queues(struct xsk_socket *xsk)
goto out;
}
- if (channels.max_combined == 0 || errno == EOPNOTSUPP)
+ ret = channels.max_combined + max(channels.max_rx, channels.max_tx);
+
+ if (ret == 0 || errno == EOPNOTSUPP)
/* If the device says it has no channels, then all traffic
* is sent to a single stream, so max queues = 1.
*/
ret = 1;
- else
- ret = channels.max_combined;
out:
close(fd);
--
2.19.1
