Michael S. Tsirkin wrote:
Quoting Rick Jones <[EMAIL PROTECTED]>:
Subject: why is CPU util/service demand so much higher with SDP than TCP?
So, while playing around with my new netperf SDP_RR test I've noticed that
a single-byte _RR test over SDP has a much higher transactions per second
(ie lower latency) than over TCP over the same HCA, but the CPU utilization
is _very_ much higher and the service demand (cpu per transaction) as well.
CPU util being higher makes sense with a higher transaction rate, but not
the increased service demand - well at least not to my experience thusfar.
That's expected.
SDP by default uses polling aggressively to trade off service demand for
latency.
You can play with recv_poll module parameter to tune that.
Ah, so it is doing a sit and spin waiting for traffic. I'll see about the
recv_poll module parm - is it a binary or other?
rick jones
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