cmd/trace: low_resolution_timer warning

[benburkert]

Please answer these questions before submitting your issue. Thanks!

1. What version of Go are you using (go version)?

go version go1.7beta2 darwin/amd64

1. What operating system and processor architecture are you using (go env)?

GOARCH="amd64"
GOBIN=""
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOOS="darwin"
GOPATH="/Users/benburkert"
GORACE=""
GOROOT="/usr/local/Cellar/go/1.7beta2/libexec"
GOTOOLDIR="/usr/local/Cellar/go/1.7beta2/libexec/pkg/tool/darwin_amd64"
CC="clang"
GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/jl/n78jzg3j6nb8nzbn1vvpg9xc0000gn/T/go-build951352621=/tmp/go-build -gno-record-gcc-switches -fno-common"
CXX="clang++"
CGO_ENABLED="1"

1. What did you do?

build ./fibtrace from https://play.golang.org/p/tWpeEL4jse

$ go build -o fibtrace fibtrace.go
$ ./fibtrace
$ go tool trace .fibtrace fib.trace

Then browse to the "View trace" page (/trace).

1. What did you expect to see?

The trace viewer displayed without a warning.

1. What did you see instead?

The trace viewer with a Import Warning: low_resolution_timer: Trace time is low resolution, trace may be unusable. warning.

[ianlancetaylor]

CC @dvyukov

[dvyukov]

It's not harmful. Just ignore it.
If somebody enjoys Javascript, he can dive into layers and layers of Javascript abstractions in Catapult and fix it.

[benburkert]

ok, thanks @dvyukov.

[bradfitz]

I'm going to reopen this bug. I spent time trying to find a machine with good enough timers to make that go away, but apparently the warning is always there?

This is not a good user experience.

[ianlancetaylor]

The warning has supposedly been removed from new versions of chrome, as of June.

https://codereview.chromium.org/2016863004

[cespare]

@ianlancetaylor so perhaps we simply need to re-copy the upstream sources? (The trace viewer bundled with the go tool is separate from that built into Chrome.)

[ianlancetaylor]

Oh, I didn't realize we had our own copy of the HTML. I guess we could make a new copy, or just clobber the warning message in misc/trace/trace_viewer_lean.html. It's easy to find by searching for "Trace time is low resolution" in that file.

[gopherbot]

CL https://golang.org/cl/25117 mentions this issue.

[rsc]

Not sure why this is still open. We decided the warning was not real, and it's been removed. Closing. /cc @bradfitz