[Bug 222234] head -r323246 aarch64 (Pine64+ 2GB) boot time context, sometimes: acquiring blockable sleep lock with spinlock or critical section held

[bugzilla-noreply at freebsd.org]

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=222234

--- Comment #2 from Mark Millard <markmi at dsl-only.net> ---
Created attachment 186443
  --> https://bugs.freebsd.org/bugzilla/attachment.cgi?id=186443&action=edit
patch to allow non-debug kernel booting

The patch contents derives from running into
ARMv8-A material that said:

ARM recommends that software includes a DSB instruction before any SEV
instruction.

This was because of a lack of ordering relative
to completion of memory access instructions
prior to the SEV instruction.

This does not appear to be architecturally
specific to the A64: the quote is not from
material about the A64.

But the observation is that A64 does not
seem to guarantee more. I'm not aware of
reports for other contexts.

I'll note that debug kernel builds (with at
least invariants) tends to sometimes fail
but usually boot. By contrast I've not had
a non-debug kernel boot yet.

-- 
You are receiving this mail because:
You are the assignee for the bug.