Re: if_wm.c workqueue

[Kengo NAKAHARA <k-nakahara%iij.ad.jp@localhost>]

Hi,

On 2022/05/25 23:13, Emmanuel Dreyfus wrote:
> Hello
>
> I see if_wm.c can handle packets using a workqueue. The thing is
> controlled by sysctl hw.wm0.txrx_workqueue but it is not documented
> in the ma page.
>
> What is the effect? I have a machine that has trouble handling high
> throughput (interrupts rise to 80%+), I suspect it can help, am I
> correct?

When hw.wm0.txrx_workqueue is set to 1, receive and transmit processing
of wm0 uses workqueue(9) instead of softint(9), that is, the processing
can be preempted.  As a result, userland process can run even if wm0
receives packets at very high rate.  However, that may causes degradation
of throughput and latency.


Thanks,

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Kengo NAKAHARA <k-nakahara%iij.ad.jp@localhost>