Anyone interested?
Opinions, comments?

I encountered a technical problem trying to replace the printf with KASSERT.
bus.h does not include systm.h and there are multiple places where bus.h is included before systm.h (or systm.h not included at all).
I am not looking forward to hear from Bruce Evans about yet another namespace pollution, but I am not sure what would be the best here.
Some options:

rebase to the recent head

I would check the chunksize at the beginning of the function and pick a new random value if the current value is less than SPA_MINBLOCKSIZE * 2.
There could also be a comment explaining why that is done.
Adding four individual checks rather than a single one seems to be suboptimal.

Sorry, I myself went missing for a long while.
Yes, I can commit this change.

Also, another thing that I realized is that this defensive code won't help much if a bus defines BUS1_IVAR_X and a child device requests BUS2_IVAR_Y when BUS1_IVAR_X == BUS2_IVAR_Y.
BUS_READ_IVAR / BUS_WRITE_IVAR may succeed in that case but the result could be meaningless.

I would like to commit this change as is now. And then change printf to KASSERT in a week rather than in a month.
Hope that no one would object.

A belated note that it is possible use monitor/mwait mechanism to get the power saving and inter-processor signaling at the same time.
I once had it implemented, but that code is quite out of date now. Also, it was interleaved with another, unrelated change.
Some bits:

• https://github.com/avg-I/freebsd/commit/c2acab4675b3f0e10bd17a79b49baa331a19bc92
• https://github.com/avg-I/freebsd/commit/b1abf62dfdfc0e1028a48e033f6de2f2b5f5722d

In D18670#426579, @crees wrote:

If the zfs.ko module is loaded, a zfs module exists in the kernel, but I suspect that zfs doesn't exist in a kernel with it compiled in; only zfsctrl, based on what avg has suggested

Once again, you are confusing a name of a loadable file with a name of a module. Which is not surprising as that duality is confusing. E.g., a single loadable file can contains multiple modules.
Whether ZFS is compiled into the kernel or loaded via zfs.ko, the module name is still zfsctrl. It's the module name.

In D19817#426388, @imp wrote:

This looks good to me, however I'd wait a few days to see if Scott can spot something that I can't.

remove a wrong panicstr check that was left by accident

In D19833#425585, @kib wrote:

In D19833#425441, @avg wrote:

LGTM.

I wonder if the pci_cfgregopen problem reported for AMD Ryzen systems has a similar cause...

What is the Ryzen problem ? This issue can only occur when config space is accessed before pmap is initialized, and I am only aware of pci_early_quirks which do that, which might falls to MCFG access only on some Intels.

I wonder if the pci_cfgregopen problem reported for AMD Ryzen systems has a similar cause...

• update

In D19094#417188, @slw_zxy.spb.ru wrote:

No more replays?

Thank you, Rick!

Somewhat belated question, would it make sense to mark the client created in sys_gssd_syscall() as interruptible?

I consider using the whole "Src committers" group as a reviewer to be inappropriate.
Especially for a change in a minor utility.

I haven't thoroughly examined the change, but the procedure you followed sounds good to me.
And if it works, then it is good enough for me.

In D19094#411932, @slw_zxy.spb.ru wrote:

Do you succesefull contact George?

Let me try to contact George again.

Not an expert on these matter, but I have no problem with the change.
Thanks!

Or if a "boot pool" setup is used (kernel is loaded from one pool, root is mounted from another). Or if reboot -r has been run prior to zfsbootcfg.