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.

Given the fact that users appear to depend on this (we have two PRs on it), this appears to have been an unintended change in stable/11, and it seems to violate POLA by making this change on a stable branch, I intend to commit this today unless someone objects.

@glebius : Any progress on reviewing this? IIRC, you didn't like overloading the SS_ISDISCONNECTED flag to indicate listen sockets that were shutdown. Do you have an alternate proposal?

Is everyone OK with this going in? Or, to ask it differently, is anyone not OK? The 11.2 release is underway, so it would be good to get this in soon, if we agree to fix it in stable/11.

BTW, it looks like this was introduced in r331214. Since it is so new, my "not widely used" comment is probably both true and somewhat irrelevant.

In D15337#323278, @mmacy wrote:

In D15337#323183, @jtl wrote:

How does this interact with the low-latency, high-precision timestamp option being discussed at the IETF?

See https://tools.ietf.org/html/draft-wang-tcpm-low-latency-opt-00 and https://www.ietf.org/proceedings/97/slides/slides-97-tcpm-tcp-options-for-low-latency-00.pdf .

@jtl I was under the impression that that discussion had stalled. The RFC you point at expired on December 10, 2017. Is there a mailing list where this is being discussed or do I need to mail them individually?

How does this interact with the low-latency, high-precision timestamp option being discussed at the IETF?

In D14993#320674, @tuexen wrote:

I'm not sure it is a good idea to have a sysctl for the default value. I would prefer to have the default value always be 0 (not changeable by a sysctl) and required the application to set a non-default value via the socket option. Why is there a need to change the default from "off" on a system wide base?

In D15021#319135, @emaste wrote:

Presumably we need to agree on and commit D15019 first, and commit this as a MFC in spirit after the change in HEAD.

If we're going to get this into 11.2, it would be nice if someone reviewed this soonish.

Looks good. Please check on two things before committing:

1. I don't see a svn:keywords property change for head/share/pgpkeys/thj.key. I expected to see one, although this could just be a Phabricator display issue. Can you confirm you've followed the instructions in the Note at the start of 5.3.7 of the Committer's Guide ("Adding and Removing Files")? If not, please do so and then svn remove and svn add the file again. You can check that the property was correctly applied by running this command: svn propget svn:keywords thj.key. You should see FreeBSD=%H.
2. Please check on the indentation in news.xml. (See in-line note.)

See nits inline.

This fix should work with HEAD.

No, this is not the right fix for head. However, if I change the spelling of SOLISTENING(so) to (so->so_options & SO_ACCEPTCON), then I think it is the right fix for 11.

In D14988#315317, @imp wrote:

How much of a difference does this make in write speed for the dumps? Do we have numbers on it?

This was already committed in rS288412.

I'll OK the sys/netinet/tcp_subr.c change on behalf of transport. :-)

In D14827#311859, @mav wrote:

I'll need to look on it closer to recall all the details, but so far my main worry about your patches is that you are increase scope of ET_HW_LOCK(), which may be a problem for SMP system with non-per-CPU event timers, where that lock is global. I remember there were cases of 8-core systems using HPET by default, where this lock was pretty busy.

FYI, @rrs already gave an offline approval for this.

In D14828#311827, @kib wrote:

What are the delays without these changes ?

Can someone please review this? This has been outstanding for a while...

Starting the (approx.) 48-hour countdown timer until commit.