Re: [PATCH v3 07/15] lockdep: Implement crossrelease feature

[Peter Zijlstra]

On Tue, Sep 13, 2016 at 12:05:20PM +0200, Peter Zijlstra wrote:
> On Tue, Sep 13, 2016 at 06:45:06PM +0900, Byungchul Park wrote:
> > Crossrelease feature calls a lock 'crosslock' if it is releasable
> > in any context. For crosslock, all locks having been held in the
> > release context of the crosslock, until eventually the crosslock
> > will be released, have dependency with the crosslock.
> > 
> > Using crossrelease feature, we can detect deadlock possibility even
> > for lock_page(), wait_for_complete() and so on.
> > 
> 
> Completely inadequate.
> 
> Please explain how cross-release does what it does. Talk about lock
> graphs and such.
> 
> I do not have time to reverse engineer this stuff.

Blergh, I'll do it anyway.. hold on for an email asking specific
questions.