Re: Go programs only using one CPU core

On Fri, Mar 26, 2021 at 08:54:23PM -0000, Stuart Henderson wrote:
> On 2021-03-26, Richard Ulmer <maillists.rulmer@mailbox.org> wrote:
> > Hi,
> > it seems to me like Go (from the lang/go port) does not utilize more
> > than one CPU core on OpenBSD. Let's take this program, which may be run
> > with `go run main.go`:
> >
> > package main
> > func main() {
> > go work()
> > work()
> > }
> > func work() {
> > for i := 1; ; {
> > i *= 1
> > }
> > }
> >
> > The `go` directive starts a new goroutine, which I would expect to be
> > put into it's own process here. However, using htop(1) I can see, that
> > only one of my two cores gets load. Running the same program on Linux,
> > two cores are utilized.
> >
> > Can someone explain to me why this is happening? Is there any way to
> > make the program use both cores of my CPU?
> >
> > Best Regards,
> > Richard Ulmer
> >
> >
>
> It works for me (checked using top and pressing H to show threads).
>
> Is your system actually dual-core or is it single core with hyperthreading?
> (it's always worth including dmesg when asking a question, that would have
> shown this)
>
>

FWIW, I also get two threads on two of my four CPUS (i7), running March
23rd's snapshot (amd64) with a never-before-installed go-1.16.2.

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