On Thu, Jun 19, 2014 at 7:00 PM, Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: >> >> + BUG_ON(f1->context != f2->context); >> > >> > Nice, you just crashed the kernel, making it impossible to debug or >> > recover :( >> >> agreed, that should probably be 'if (WARN_ON(...)) return NULL;' >> >> (but at least I wouldn't expect to hit that under console_lock so you >> should at least see the last N lines of the backtrace on the screen >> ;-)) > > Lots of devices don't have console screens :) Aside: This is a pet peeve of mine and recently I've switched to rejecting all patch that have a BUG_ON, period. Except when you can prove that the kernel will die in the next few lines and there's nothing you can do about it a WARN_ON is always better - I've wasted _way_ too much time debugging hard hangs because such a "benign" BUG_ON ended up eating my irq handler or a spinlock required by such. Or some other nonsense that makes debugging a royal pita, especially if your remote debugger consists of a frustrated users staring at a hung machine. </rant> Cheers, Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
