Messages in this thread | | | Date | Mon, 20 Mar 2006 10:58:25 -0800 | From | Rick Jones <> | Subject | Re: TSO and IPoIB performance degradation |
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> Wouldn't it make sense to strech the ACK when the previous ACK is still in > the TX queue of the device? I know that sort of behaviour was always an > issue on modem links where you don't want to send out redundant ACKs.
Perhaps, but it isn't clear that it would be worth the cycles to check. I doubt that a simple reference count on the ACK skb would do it since if it were a bare ACK I doubt that TCP keeps a reference to the skb in the first place?
Also, what would be the "trigger" to send the next ACK after the previous one had left the building (Elvis-like)? Receipt of N in-order segments? A timeout?
If you are going to go ahead and try to do stretch-ACKs, then I suspect the way to go about doing it is to have it behave very much like HP-UX or Solaris, both of which have arguably reasonable ACK-avoidance heuristics in them.
But don't try to do it quick and dirty.
rick "likes ACK avoidance, just check the archives" jones on netdev, no need to cc me directly - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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