Re: [RFC] HOWTO use NAPI to reduce TX interrupts

From: Roland Dreier
Date: Mon Aug 21 2006 - 20:26:34 EST

David> Don't touch interrupts until both RX and TX queue work is
David> fullydepleted. You seem to have this notion that RX and TX
David> interrupts are seperate. They aren't, even if your device
David> can generate those events individually. Whatever interrupt
David> you get, you shut down all interrupt sources and schedule
David> the ->poll(). Then ->poll() does something like:

This is a digression from spidernet, but what if a device is able to
generate separate MSIs for TX and RX? Some people from IBM have
suggested that it is beneficial for throughput to handle TX work and
RX work for IP-over-InfiniBand in parallel on separate CPUs, and
handling everything through the ->poll() method would defeat this.

- R.
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