* TCP CUBIC and IPoIB
@ 2010-11-09 0:58 Jason Gunthorpe
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From: Jason Gunthorpe @ 2010-11-09 0:58 UTC (permalink / raw)
To: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
I wonder if anyone has ever looked at this? It looks like there is
something wrong here.
I was just looking at some results from a stock 2.6.35 kernel doing
TCP over IPoIB (2k MTU) and CUBIC looks like it is going nutz, you can
see in a bandwidth plot a fairly characteristic saw tooth pattern, and
diminished bandwidth. The effect compounds rather dramatically as the
RTT goes up.
This isn't really my area of expertise, so I wonder if someone else
has looked into this? Errant congestion events will sap bandwidth
even on low latency links..
Cheers,
Jason
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2010-11-09 0:58 TCP CUBIC and IPoIB Jason Gunthorpe
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