On Tue, 2012-08-14 at 10:30 -0400, Steven Rostedt wrote: > Thomas, > > Ben Hutchings asked me if we still need "genirq: Disable random call on > preempt-rt" for -rt? With commit 902c098a366 "random: use lockless > techniques in the interrupt path" there is no more locks used. But does > it still produce high latencies? Ben, Looks that the #ifndef can't be removed just yet. The code is not totally lockless... add_interrupt_randomness -> credit_entropy_bits -> kill_fasync -> kill_fasync_rcu -> spin_lock_irqsave(&fa->fa_lock, flags) to make things worse, that spinlock turns into a mutex on -rt, so it may crash the box if triggered. -- Steve -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
