Re: [PATCH] eliminate large inline's in skbuff

[Stephen Hemminger <shemminger@xxxxxxxx>]

> On Wednesday 28 April 2004 00:21, Stephen Hemminger wrote:
> > This takes the suggestion and makes all the locked skb_ stuff, not inline.
> > It showed a 3% performance improvement when doing single TCP stream over 1G
> > Ethernet between SMP machines. Test was average of 10 iterations of
> > iperf for 30 seconds and SUT was 4 way Xeon.  Http performance difference
> > was not noticeable (less than the std. deviation of the test runs).

The original tests were suspect for a whole lot of reasons.  Running the proper
tests shows no performance differences.  The best theory as to why there was
a difference in earlier tests is that memory debugging was enabled;  that caused
each buffer to be overwritten with a memset. When that happened, the test
ends up measuring the speed of the memory and cache bandwidth, not the CPU or
the network.