Re: [PATCH net-next v3] net: dqs: add NIC stall detector based on BQL

Jakub Kicinski
2024-02-13T18:04:58Z

On Tue, 13 Feb 2024 14:57:49 +0100 Eric Dumazet wrote:
> Please note that adding other sysfs entries is expensive for workloads
> creating/deleting netdev and netns often.
>
> I _think_ we should find a way for not creating
> /sys/class/net/<interface>/queues/tx-{Q}/byte_queue_limits directory
> and files
> for non BQL enabled devices (like loopback !)

We should try, see if anyone screams. We could use IFF_NO_QUEUE, and
NETIF_F_LLTX as a proxy for "device doesn't have a real queue so BQL
would be pointless"? Obviously better to annotate the drivers which
do have BQL support, but there's >50 of them on a quick count..