On Tue, May 01, 2018 at 12:18:45PM +0200, Peter Zijlstra wrote: > Aaaah... I think I've spotted a problem there. We clear SHOULD_PARK > before we rebind, so if the thread lost the first PARKED store, > does the completion, gets migrated, cycles through the loop and now > observes !SHOULD_PARK and bails the wait-loop, then __kthread_bind() > will forever wait. > > Is that what you had in mind? Another possible problem is concurrent thread_park(), if both observe !IS_PARKED, we'll end up with 2 threads waiting on the completion, but we only do a single complete(). Of course, this might not be a suppored use of the API, and I don't think this will ever actually happen. But the whole !test_bit(IS_PARKED) thing seems to suggest it is fine calling this on an already parked thread. Confusing stuff that should be cleared up in any case. -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
