Re: building netbsd-9 2 'sync' processes stuck in 'tstile'

["John D. Baker" <jdbaker%consolidated.net@localhost>]

On Sat, 8 May 2021, Robert Elz wrote:

>     From:        "John D. Baker" <jdbaker%consolidated.net@localhost>
> 
>   | So far, the now 6 'sync' processes have been stuck in "tstile" for 4
>   | days.
> 
> They are extermely unlikely to ever go away, that's a kernel locking bug.
> What version is the system you're running (not the one you're building,
> that's irrelevant to this) ?

The running system is netbsd-9 (9.1_STABLE) from around 30 April 2021
although the last substantive kernel update (from 'uname -a') seems to
have been around 27 March 2021.

> You need a reboot to fix this.

I expected as much.  It will be interesting to see what happens.  I've
had systems with stuck processes get stuck in the shutdown sequence
requiring a hard reset (or forced power-cycle) to recover.

> Some little used vnode is likely locked.   As long as nothing references that
> particular one, everything is fine.   Anything which accesses the file (in
> the generic sense, ie: including directories etc) in question will hang.

I just ran a full forced 'fsck -yf' on it just prior to these events.
That was prompted by CVS failing to clean up a directory.  I get those
from time to time after the near-catastrophic events that prompted
kern/55115.  I used to get them frequently.  Now they are less common.
The carnage might still have caught the build this time.

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