Hi. I know I'm late to the party, but I have three comments:
a) I could be wrong, but I don't think there is any guarantee this won't be called simultaneously for two different groups at the same time. (The groups could be in different VNETs, for example.) In that case, two different invocations could be working on the function's static variables at the same time. That may produce unexpected results. (Granted, it would take an unusual series of events. But, I think we've all seen highly unusual events occur.)
b) I don't think the const variable also needs to be static.
c) It seems like the rate limiter should really be per-group, so I would suggest adding the lastprint variable to the inpcblbgroup struct.

FYI, something didn't look right doing my tests. So, I'm going to delay committing this until I can satisfy myself that it behaves correctly. That will almost certainly mean I miss the code freeze. C'est la vie!

• Limit the ipq structure to the kernel to eliminate a buildworld failure. (And, why should we make userspace code import the sys/queue.h header for a structure they don't need anyway?)
• Address @jhb's nit.

In D16471#357964, @j-nitrology.com wrote:

D16626 expanded on these changes and was recently committed. I believe we can close this one out.

LGTM (with minor change noted in-line).

In D16626#356917, @rrs wrote:

This version incorporates all of Jonathans comments and suggested improvements. Thanks
Jonathan!!!

Never mind. It looks like this is a display issue, and you really are deleting them.

It looks like you're keeping the code by moving it to the modules directory? At this point, I think it just makes sense to delete it.

In D15706#336213, @micchie.gml_gmail.com wrote:

In D15706#335628, @rwatson wrote:

In D15706#334870, @micchie.gml_gmail.com wrote:

In D15706#334711, @jtl wrote:

In D15706#334605, @rwatson wrote:

Didn't quite catch this before it was committed. This isn't really a destructor, it's a close notification. Rather than confuse matters, as sockets have UMA destructors as well, this should probably be so_notify_close.

Yes, I caught that when I asked the submitter about the placement of the "destructor". But, once I figured out it was a close notification, I should have changed the name. Mea cupla.

Before changing this, let me see if I can confirm what the Linux implementation does.

Thanks, it is intended to be equivalent to sk_destruct() callback in struct sock in Linux.

Is the Linux sk_destruct called on socket close, or on socket destruction? If we want an actual socket destructor, we can add one of those [instead / as well], called from the socket destructor function.

It is literally destructor, which is called when the final reference count drops to zero. So probably we should define so_dtor() as destructor (so keep the name) and call it after SOCK_UNLOCK() in sofree(). (in Linux it is invoked without locking socket).

In D15706#334605, @rwatson wrote:

Didn't quite catch this before it was committed. This isn't really a destructor, it's a close notification. Rather than confuse matters, as sockets have UMA destructors as well, this should probably be so_notify_close.

I've spent some time thinking about this a bit, and I have the following comments. (Some may seem contradictory, but please bear with me. :-) )

Address @markj's feedback by always defining the vmd_kernel_rwx_arena member of the vm_domain struct.

Update the zone(9) manpage.

Okay, really without the cruft this time. (Hopefully...)

I'll try to look at this review this week.

Get the correct version of sys/vm/vm_kern.c (with the troubleshooting stuff removed).

Numerous updates:

• Address @alc's concerns by adding a new arena for allocations with non-standard permissions. Import a 2MB-aligned address block at a time into the arena. Release space back to the parent arena when able. But, only do this for architectures with superpages.
• Plumb M_EXEC through malloc(9).
• Fix BPF by reverting most of rS317072.
• Add a note to the manpage that not all architectures will enforce execution permissions.

This passes my "sniff test", but it would be better to get @pkelsey to review it.

I think there are more changes needed.

The submitter spoke to me in person at BSDCan and answered my questions.

In D15691#331801, @alc wrote:

Overall, I think that this is a good idea, but the implementation has the following problem. The allocation of one executable page will block the promotion of the surrounding pages to a superpage mapping.

Incorporate review feedback from @jhb.

I added a few basic comments while I ponder the rest...

I don't know ISA well. I'm open to switching this to be an option to always panic on any NMI, instead of picking NMI_TIMER2 for special treatment.

I'm sorry it took me so long to review this.

In D15386#330028, @brooks wrote:

Anyone on transport care about this?

In D11003#328091, @sbruno wrote:

In D11003#327485, @jtl wrote:

In D11003#327482, @sbruno wrote:

Is everyone on this review fine with me committing this? With the inheritance code removed, I believe there are no further objections or questions.

I've been meaning to review this, but have been delayed. I would appreciate a few extra days to look it over.

@jtl I'd like to commit this at some point this week, but I also want your feedback on it. Should we hold off until next week to drop this into head?

In D11003#327482, @sbruno wrote:

Is everyone on this review fine with me committing this? With the inheritance code removed, I believe there are no further objections or questions.

Having stared at this a bit, I generally think its fine. In fact, in some aspects it is an improvement over what it replaces.

In D15483#326763, @mjg wrote:

First a minor note is that I took the liberty of s/bzero/bcmp, which I presume was intended.

By the way, measurements were taken on an Intel E5-2697A v4 (32-core Broadwell).

Yes, see rS302894, rS302997, rS302998, rS303037, rS303096, and rS303098.

Sorry it took me a while to look at this. See comments in-line.