RE: [net-next 1/2] ena: Link IRQs to NAPI instances
From: Arinzon, David
Date: Tue Oct 01 2024 - 04:58:12 EST
> Link IRQs to NAPI instances with netif_napi_set_irq. This information can be
> queried with the netdev-genl API. Note that the ENA device appears to
> allocate an IRQ for management purposes which does not have a NAPI
> associated with it; this commit takes this into consideration to accurately
> construct a map between IRQs and NAPI instances.
>
> Compare the output of /proc/interrupts for my ena device with the output
> of netdev-genl after applying this patch:
>
> $ cat /proc/interrupts | grep enp55s0 | cut -f1 --delimiter=':'
> 94
> 95
> 96
> 97
> 98
> 99
> 100
> 101
>
> $ ./tools/net/ynl/cli.py --spec Documentation/netlink/specs/netdev.yaml \
> --dump napi-get --json='{"ifindex": 2}'
>
> [{'id': 8208, 'ifindex': 2, 'irq': 101},
> {'id': 8207, 'ifindex': 2, 'irq': 100},
> {'id': 8206, 'ifindex': 2, 'irq': 99},
> {'id': 8205, 'ifindex': 2, 'irq': 98},
> {'id': 8204, 'ifindex': 2, 'irq': 97},
> {'id': 8203, 'ifindex': 2, 'irq': 96},
> {'id': 8202, 'ifindex': 2, 'irq': 95},
> {'id': 8201, 'ifindex': 2, 'irq': 94}]
>
> Signed-off-by: Joe Damato <jdamato@xxxxxxxxxx>
> ---
> drivers/net/ethernet/amazon/ena/ena_netdev.c | 12 +++++++++++-
> 1 file changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.c
> b/drivers/net/ethernet/amazon/ena/ena_netdev.c
> index c5b50cfa935a..e88de5e426ef 100644
> --- a/drivers/net/ethernet/amazon/ena/ena_netdev.c
> +++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c
> @@ -1679,7 +1679,7 @@ static int ena_request_io_irq(struct ena_adapter
> *adapter)
> u32 io_queue_count = adapter->num_io_queues + adapter-
> >xdp_num_queues;
> unsigned long flags = 0;
> struct ena_irq *irq;
> - int rc = 0, i, k;
> + int rc = 0, i, k, irq_idx;
nit: This breaks RCT guidelines, can you please move it to be below io_queue_count?
>
> if (!test_bit(ENA_FLAG_MSIX_ENABLED, &adapter->flags)) {
> netif_err(adapter, ifup, adapter->netdev, @@ -1705,6 +1705,16 @@
> static int ena_request_io_irq(struct ena_adapter *adapter)
> irq_set_affinity_hint(irq->vector, &irq->affinity_hint_mask);
> }
>
> + /* Now that IO IRQs have been successfully allocated map them to the
> + * corresponding IO NAPI instance. Note that the mgmnt IRQ does not
> + * have a NAPI, so care must be taken to correctly map IRQs to NAPIs.
> + */
> + for (i = 0; i < io_queue_count; i++) {
> + irq_idx = ENA_IO_IRQ_IDX(i);
> + irq = &adapter->irq_tbl[irq_idx];
> + netif_napi_set_irq(&adapter->ena_napi[i].napi, irq->vector);
> + }
> +
> return rc;
>
> err:
> --
> 2.43.0
Thank you for uploading this patch.