On 10/03, Linus Torvalds wrote: > > On Fri, Oct 3, 2014 at 5:01 PM, Linus Torvalds > <torva...@linux-foundation.org> wrote: > > > > The real fix would appear to be to use > > "preempt_enable_no_resched_notrace()", which your patch did, but > > without the loop. > > Actually, the real fix would be to not be stupid, and just make the > code do something like > > > if (likely(!preemptible())) > > return; > > > > __preempt_count_add(PREEMPT_ACTIVE); > > prev_ctx = exception_enter(); > > > > __schedule(); > > > > exception_exit(prev_ctx); > > __preempt_count_sub(PREEMPT_ACTIVE); > > and *not* enable preemption around the scheduling at all. The whole > enable and then re-disable seems entirely broken, and comes from the > code using "preempt_schedule()" which doesn't work while preemption is > disabled. So don't do that then.
Again, it is too late for me... Most probably I am wrong, but somehow it seems to me that the real fix should try to kill preempt_schedule_context() altogether and teach preempt_schedule() to play well with CONTEXT_TRACKING. Oleg. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/