* Dave Jones davej@redhat.com wrote:
It's crossed my mind to turn it on occasionally in rawhide just to shake out those hard to find bugs. The thing that's put me off has been that well, we've got enough bugs already without needing to find more right now.
it's on by default in -rt and i havent had a bug triggered by it for quite a long time. We had many SMP races triggered by PREEMPT_RT.
part of the reason of PREEMPT_BKL's reliability is because when i did it i also wrote debugging infrastructure to catch bugs that would only trigger on PREEMPT_BKL=y: the smp_processor_id() debugging code of CONFIG_DEBUG_PREEMPT. (and that infrastructure, like lockdep, catches bugs before they actually happen, by flagging buggy codepath the first time it ever executes)
Ingo