On Tue, Sep 3, 2013 at 8:14 AM, Waiman Long <waiman.long@xxxxxx> wrote: > > Other than the global tty_ldisc_lock, there is no other major > bottleneck. I am not that worry about the tty_ldisc_lock bottleneck > as real world applications probably won't have that many calls to > set the tty driver. I suspect the tty_ldisc_lock() could be made to go away if we care. Making the ldisc be rcu-free'd, coupled with just optimistically updating the count using "atomic_inc_not_zero()" and re-checking the ldisc pointer afterwards should probably do it. But I agree that it probably isn't worth it for any actual real load. Linus -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html