From: "Qinghua(Kevin) Ye" <[EMAIL PROTECTED]> Date: Wed, 6 Jul 2005 11:36:40 -0600
> > > Compared to NAPI, click polling will disable Nic interrupts during its > > > operation, even there is no any packets in the rx buffer. > > > > This destroys latency if you only recheck the RX buffer using > > timer interrupts. Even with HZ=1000, on gigabit links your packet > > latency will be terrible. We've tried this before. > > > The latency incurred will be a problem on all Nics, or just on tg3? What's > the overhead cause this latency? Since the Click will use CPU exclusively > and poll the status all the time, why there will be terrible latency? It's driver agnostic. Since the timer ticks only as fast as the HZ supported on the platform, the lowest latency you can obtain from timer based rechecking is 1 HZ. So you're not using a timer, and will just poll like crazy until some packets arrive? That sounds like a waste of cpu cycles to me. - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
