Re: [PATCH net-next v4 2/2] virtio-net: add cond_resched() to the command waiting loop

From: Michael S. Tsirkin
Date: Thu Jul 27 2023 - 05:48:40 EST


On Thu, Jul 27, 2023 at 04:59:33PM +0800, Jason Wang wrote:
> > They really shouldn't - any NIC that takes forever to
> > program will create issues in the networking stack.
>
> Unfortunately, it's not rare as the device/cvq could be implemented
> via firmware or software.

Currently that mean one either has sane firmware with a scheduler that
can meet deadlines, or loses ability to report errors back.

> > But if they do they can always set this flag too.
>
> This may have false negatives and may confuse the management.
>
> Maybe we can extend the networking core to allow some device specific
> configurations to be done with device specific lock without rtnl. For
> example, split the set_channels to
>
> pre_set_channels
> set_channels
> post_set_channels
>
> The device specific part could be done in pre and post without a rtnl lock?
>
> Thanks


Would the benefit be that errors can be reported to userspace then?
Then maybe. I think you will have to show how this works for at least
one card besides virtio.


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MST