Hey, Op 05-02-13 21:52, Ben Skeggs schreef: > On Mon, Feb 04, 2013 at 10:59:28PM +0100, Maarten Lankhorst wrote: >> Op 04-02-13 22:30, Marcin Slusarz schreef: >>> 1) Lockdep thinks all nouveau subdevs belong to the same class and can be >>> locked in arbitrary order, which is not true (at least in general case). >>> Tell it to distinguish subdevs by (o)class type. >> Apart from this specific case, is there any other reason why we require being able to nest 2 subdev locks? > I think I tend to prefer Marcin's fix for this actually. The subdev's > are completely separate classes of objects and as interaction between > them increases (PM will be very much like this), we may very well > require holding multiple subdev mutexes at once. > > Ben. Depends, I think for this specific example I think my cleanup is better. For the generic case you could use nested mutexes, which will give you a different lockdep class when you need it. It's probably better to have those cases where you do need to nest locking annotated: mutex_lock_nested(&mutex, SINGLE_DEPTH_NESTING); See also Documentation/lockdep-design.txt ~Maarten _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
