From: Hrvoje Popovski <hrvoje@srce.hr>
Subject: Re: Adjust amd64 IPLs
To: tech@openbsd.org, Jan Klemkow <j.klemkow@wemelug.de>
Date: Mon, 15 Jan 2024 09:13:06 +0100

On 2.1.2024. 21:27, Jan Klemkow wrote:
> On Mon, Jan 01, 2024 at 07:12:31PM +0100, Mark Kettenis wrote:
>> On amd64, we only have 240 interrupt vectors, which means they're a
>> limited.  And unless I'm terribly confused, we're not using 48 of
>> those because of the way we've assigned the priority levels.  And with
>> more and more devices supporting multiple interrupt vectors, we can
>> put these to good use.  So this diff rearranges the levels to make the
>> additonal vectors available for use.  Since it most likely network
>> devices that need these, I leave a gap between between IPL_NET and
>> IPL_SOFTTTY.  That way, it will take longer for IPL_NET interrupts to
>> spill over into the IPL_SOFTTTY range and mess up the interrupt
>> priorities.
>>
>> Now I vagelue remember something about trying something like this
>> before.  So I want to make sure this doesn't cause any problems.
>> Therefore I'd appreciate it if people can test this, especially on
>> machines with lots of network devices.
> Together with the multiqueue diff for em(4) from jmatthew@ the interrupt
> error of em18 just changed.  I guess it got some more interrupts
> allocates, but still not enough.  Thus, also on this machine the
> interrupt issue improves.
> 
> Thanks,
> Jan


Hi Jan,

is em multiqueue diff from jmatthew@ good enough for production? It was
working fine when I tested forwarding and I remember that you said that
something isn't working as expected