Re: [PATCH] kthread: finer-grained lockdep/cross-release completion

[Daniel Vetter]

On Mon, Dec 11, 2017 at 10:19:28AM +0100, Daniel Vetter wrote:
> On Fri, Dec 08, 2017 at 11:54:19AM +0100, Peter Zijlstra wrote:
> > On Thu, Dec 07, 2017 at 11:08:49AM +0100, Daniel Vetter wrote:
> > > Since -rc1 we're hitting a bunch of lockdep splats using the new
> > > cross-release stuff around the 2 kthread completions. In all cases
> > > they are because totally independent uses of kthread are mixed up by
> > > lockdep into the same locking class, creating artificial deadlocks.
> > > 
> > > Fix this by converting kthread code in the same way as e.g.
> > > alloc_workqueue already works: Use macros for the public api so we can
> > > have a callsite specific lockdep key, then pass that through the
> > > entire callchain. Due to the many entry points this is slightly
> > > tedious.
> > > 
> > > Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>
> > > Cc: Marta Lofstedt <marta.lofstedt@xxxxxxxxx>
> > > Cc: Byungchul Park <byungchul.park@xxxxxxx>
> > > Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> > > Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> > > Cc: Tejun Heo <tj@xxxxxxxxxx>
> > > Cc: Kees Cook <keescook@xxxxxxxxxxxx>
> > > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> > > Cc: Shaohua Li <shli@xxxxxx>
> > > Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> > > Cc: Jens Axboe <axboe@xxxxxxxxx>
> > > Cc: Daniel Vetter <daniel.vetter@xxxxxxxx>
> > > Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> > > Cc: Jonathan Corbet <corbet@xxxxxxx>
> > > Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
> > > References: https://bugs.freedesktop.org/show_bug.cgi?id=103950
> > > Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxxx>
> > 
> > Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
> 
> Who's going to pick this up? Ingo, Andrew?

This didn't seem to have made it into -rc4. Anything needed to get it
going?

Thanks, Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch