On Tue, Oct 01, 2013 at 09:28:15AM +0200, Ingo Molnar wrote: > That I mostly agree with, except that without a serious usecase do we have > a guarantee that bugs in fancies queueing in rwsems gets ironed out?
Methinks mmap_sem is still a big enough lock to work out a locking primitive :-) In fact, try something like this from userspace: n-threads: pthread_mutex_lock(&mutex); foo = mmap(); pthread_mutex_lock(&mutex); /* work */ pthread_mutex_unlock(&mutex); munma(foo); pthread_mutex_unlock(&mutex); vs n-threads: foo = mmap(); /* work */ munmap(foo); I've had reports that the former was significantly faster than the latter. -- 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/
