fmt: TestCountMallocs: fmt_test.go:607: Fprintf(buf, "%s"): got 1.21 allocs, want <=1

[alberts]

What steps will reproduce the problem?

GOMAXPROCS=19 ./run.bash --no-rebuild

What is the expected output?

test passes

What do you see instead?

--- FAIL: TestCountMallocs-19 (0.01 seconds)
fmt_test.go:607: Fprintf(buf, "%s"): got 1.21 allocs, want <=1
FAIL
FAIL fmt 0.064s

Which compiler are you using (5g, 6g, 8g, gccgo)?

6g

Which operating system are you using?

linux

Which version are you using?  (run 'go version')

go version devel +67fc3cb0d3aa Mon Mar 04 14:54:36 2013 +1100 linux/amd64

[alberts]

Comment 1:

some goodies from
go tool pprof --svg --alloc_objects ./fmt.test memprof.profile
had to hack the testing package to write a memprofile when it fails.
it seems in the failure case, runtime.allocm sometimes calls runtime.malg.

Attachments:

1. ok.svg (98580 bytes)
2. fail.svg (72234 bytes)

[rsc]

Comment 2:

I think any TestCountMallocs test should just refuse to run if GOMAXPROCS
is not 1.

[robpike]

Comment 3:

This issue was closed by revision 0a71a5b.

Status changed to Fixed.