Re: [PATCH] Separate target visibility from reaped state information

[Sebastian Herbszt <herbszt@gmx.de>]

James Bottomley wrote:
> On Tue, 2016-01-19 at 19:30 -0500, Martin K. Petersen wrote:
> > > > > > > "Bart" == Bart Van Assche <bart.vanassche@sandisk.com>
> > > > > > > writes:
> > 
> > Bart> Instead of representing the states "visible in sysfs" and "has
> > Bart> been removed from the target list" by a single state variable,
> > use
> > Bart> two variables to represent this information.
> > 
> > James: Are you happy with the latest iteration of this? Should I
> > queue
> > it?
> 
> Well, I'm OK with the patch: it's a simple transformation of the
> enumerated state to a two bit state.  What I can't see is how it fixes
> any soft lockup.
> 
> The only change from the current workflow is that the DEL transition
> (now the reaped flag) is done before the spin lock is dropped which
> would fix a tiny window for two threads both trying to remove the same
> target, but there's nothing that could possibly fix an iterative soft
> lockup caused by restarting the loop, which is what the changelog says.
> 
> James

James, Martin, what's the status of this patch?
I still hit the reported soft lockup on 4.5-rc1.

Sebastian