At work we decided to use the approach of if_gif / if_gre.
So, we don't really need this change.
But if people find it useful (e.g. @ae) and no one objects (looking at @bz), then I would like to commit this change and to merge if we have a spare field.

correct description of the new sysctl

While here, I also fixed setting of the next state in the case of malloc failure in DA_STATE_PROBE_WP.

Unfortunately, I disagree with this change. I think that it is backwards.
illumos has already translated their zfs.1m and zpool.1m to mdoc format, so I assume that that's the direction they are moving in.
I'd rather help them with that in this case as well.
IMO, that would be a better way to overcome the divergence.

• add and make use of rman_{get,set}_irq_cookie() and a new field r_irq_cookie to back them
• slide up head

In D18420#392363, @ae wrote:

I'm inclined to agree. For tunneling interfaces I used global per-driver sx lock to prevent concurrent ioctl invocation. I think these drivers are not affected by this problem.

In D18420#392349, @ae wrote:

Can you provide an example, what another driver needs such method? Maybe it is enough to fix the problem locally in if_lagg for first time?

In D18420#392053, @bz wrote:

Sorry but my understanding is that this could possibly free the softc even before lagg_clone_destroy() has finished, couldn't it?

Maybe rather than removing the code it would be better to ifdef it out?
But not sure. What are plans for illumos in this respect?

In D17465#386206, @selwinsebastian_gmail.com wrote:

Scheduler should be aware of the topology of socket also as to keep threads in same socket if possible while migration as

I see what the change does but not why. Could you please provide some rationale?

In D17585#375321, @mav wrote:

I have no particular objections, just quietly sighing that this area remains so tangled. I haven't investigated the area much recently, but it seems like WDAT-based attach could be cleaner, if it is a widespread standard and does not conflict too badly with existing drivers. Having watchdog drivers enabled in FreeNAS for years we had huge number of complains, caused by random platform specifics, and obtaining some valid configuration directly from platform in face of this table could be priceless.

Another note is that the test system has a BIOS option to enable the watchdog support. That option does not seem to affect the hardware configuration in any way, but when it is enabled the firmware generates WDAT (WatchDog Action Table) ACPI table. I see that Linux now has a driver for that table:
https://github.com/torvalds/linux/commits/master/drivers/watchdog/wdat_wdt.c

Looks good to me.

LGTM. The change is trivial enough.

I am really happy that this simple change greatly reduces the chances of hitting the problem.
My understanding of it is in the bug report.

ZFS part looks good to me.

LGTM. Thank you!

• add a barrier function to ensure that the interrupt handling code sees that a handler is suspended after intr_event_suspend_handler() returns

Terry, thank you!

I've just tested this and I see a couple of issues.

rebase

I am considering all previous requests for changes as outdated and I am going to commit this.
Please state if you still have any objections.

In D16459#350746, @eugen_grosbein.net wrote:

I'm going to commit latest revision soon unless an objection is raised.

In D15905#348331, @cem wrote:

It was this: https://reviews.freebsd.org/D15905#338982

Which has been completed. I don't know of a way in phabricator to un-request changes other than approving, which isn't quite the same thing.

Well, the standard says (0 ..64) and that means from zero to 64.
Also, my impression is that, according to the RFC, ifAlias is something that should be settable over SNMP and it should be persistent.

Some comments inline, but in general looks good to me.
Thanks!

remove TESTING / KFAIL code

Per suggestions from Samy Al Bahra:

@cem, you are shown as having requested a change but looking into the comment history I am not sure what that change might be.
Could you please clarify?

rebase