Re: evbarm hang

[Jason Thorpe <thorpej%me.com@localhost>]

> On Apr 21, 2019, at 3:29 AM, Manuel Bouyer <bouyer%antioche.eu.org@localhost> wrote:
> 
>> Also, Jason suggested initialising kernel_pmap pm_obj_lock appropriately
>> to help simplify pmap_{acquire,release}_pmap_lock further.
> 
> I didn't see Jason's message. I guess he suggested making kpm->pm_obj_lock
> an IPL_VM lock. I can make that, and indeed it'll avoid a test in
> pmap_{acquire,release}_pmap_lock. But then we'll need a separate IPL_NONE
> lock for pmap_growkernel() (we can't use a IPL_VM lock here because
> pmap_grow_map() may sleep).

Yes, that's right.  Then having a separate lock for grow kernel seems fine... alternatively, drop the IPL_VM lock before the call that sleeps, reacquire, and check to see if you lost the race.

-- thorpej