What steps will reproduce the problem?
Run Dave Cheney's autobench tools on FreeBSD/amd64. See:
Which compiler are you using (5g, 6g, 8g, gccgo)?
Which operating system are you using?
Which version are you using? (run 'go version')
go version go1.1 freebsd/amd64
Please provide any additional information below.
Seeing a performance regression in the net/http package on FreeBSD. I was able to detect
it using Dave Cheney's autobench tools, which compares 1.03 and 1.1 using the built-in
benchmark tests (https://github.com/davecheney/autobench).
In particular, there seems to be a regression in the client/server performance.
Here is a snippet from the attached benchcmp output (comparing 1.03 and 1.1 on FreeBSD):
benchmark old ns/op new ns/op delta
BenchmarkHTTPClientServer 144770 8017199 +5437.89%
BenchmarkClientServer 156708 8017160 +5015.99%
BenchmarkClientServerParallel4 185736 2019450 +987.27%
BenchmarkClientServerParallel64 172426 209856 +21.71%
BenchmarkServer 148844 4050047 +2621.00%
I also compared the http benchmarks on Linux and FreeBSD for Go 1.1 and saw that FreeBSD
was significantly slower. I've attached benchcmp output for that as well.
Without looking at anything but the numbers, I can say that a delta like that is almost
certainly due to an unfortunate location for a stack segment boundary. We're working on
ways to avoid that in future, by arranging stacks in a different way.