[9fans] any updates on go for plan9/arm?

[9fans] any updates on go for plan9/arm?

[Skip Tavakkolian]

I just tried cross compiling go1.6beta1 for plan9/arm, using os
x, but no luck.  is it still planned for go1.6?

Re: [9fans] any updates on go for plan9/arm?

[lucio]

> I just tried cross compiling go1.6beta1 for plan9/arm, using os
> x, but no luck.  is it still planned for go1.6?

I don't recall any formal submission for that and I'm pretty sure that
it was not on the road map for 1.6.

I know Richard did all the hard work to port Go, but it really is in
the hand of the Go community to make it happen.  What Richard
submitted was more in the line of proof of concept and will need some
adjusting (I seem to recall a tar archive?).

Cherry got Go on linux/mips64 going practically alone, it can't be
beyond our means to do it for plan9/arm (and plan9/mips?).

Lucio.

Re: [9fans] any updates on go for plan9/arm?

[David du Colombier]

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Richard Miller's work on the plan9/arm port is available here:

http://9legacy.org/go/patch/go-arm.diff

It has been tested successfully on Rasperry Pi 2 (ARMv7) with *ncpu=1.

There is still a coherency issue that need to be fixed to be able to run
reliably on multiple processors.

--
David du Colombier

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Re: [9fans] any updates on go for plan9/arm?

[lucio]

> http://9legacy.org/go/patch/go-arm.diff

Thank you, David for the details.  There are many rPi owners out there
and some may be willing to contribute their efforts, it matters that
they are well informed.

Is the coherency problem documented anywhere?  I appreciate I ought to
know the answer, but I don't own a Pi and have not given this as much
attention as I believe I ought to.

Lucio.

Re: [9fans] any updates on go for plan9/arm?

[Richard Miller]

> Richard Miller's work on the plan9/arm port is available here:
>
> http://9legacy.org/go/patch/go-arm.diff
>
> It has been tested successfully on Rasperry Pi 2 (ARMv7) with *ncpu=1.

I think that's a diff against go1.5 -- and it runs on older rpi (ARMv6) too.

In order to pass all the go test suite, a few small plan 9 patches are
required as well.

/n/sources/contrib/miller/go-plan9-arm.tar holds the latest snapshot.
I haven't touched this for a while, so I'll see if it needs updating
for the present state of Go.

Re: [9fans] any updates on go for plan9/arm?

[Richard Miller]

> Is the coherency problem documented anywhere?  I appreciate I ought to
> know the answer, but I don't own a Pi and have not given this as much
> attention as I believe I ought to.

The kernel in /n/sources/contrib/miller/9/bcm supports multicore on the
Raspberry Pi 2, but has an elusive "one last bug" which I suspect has to
do with cache or page table coherency.  The symptom is very infrequent
memory corruption under heavy load, and the go test suite with *ncpu=4
occasionally triggers it.

Re: [9fans] any updates on go for plan9/arm?

[David du Colombier]

I've just updated the patch so it should apply cleanly on Go 1.6.

Richard, I think the following files have to be updated
to match Go 1.6:

 - src/cmd/go/build.go (rebase to the current file)
 - src/runtime/os3_plan9.go (regSize → sys.RegSize,
   ptrSize → sys.PtrSize and go:nowritebarrier → go:nowritebarrierrec)
 - src/runtime/sys_plan9_386.s (m_errstr(BX) → (m_mOS+mOS_errstr)(BX))

-- 
David du Colombier

Re: [9fans] any updates on go for plan9/arm?

[David du Colombier]

> I've just updated the patch so it should apply cleanly on Go 1.6.
> 
> Richard, I think the following files have to be updated
> to match Go 1.6:
> 
>  - src/cmd/go/build.go (rebase to the current file)
>  - src/runtime/os3_plan9.go (regSize → sys.RegSize,
>    ptrSize → sys.PtrSize and go:nowritebarrier → go:nowritebarrierrec)
>  - src/runtime/sys_plan9_386.s (m_errstr(BX) → (m_mOS+mOS_errstr)(BX))

And move cas and casp1 functions from src/runtime/sys_plan9_arm.s to
src/runtime/internal/atomic/sys_plan9_arm.s.

-- 
David du Colombier

Re: [9fans] any updates on go for plan9/arm?

[Charles Forsyth]

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On 31 December 2015 at 11:57, Richard Miller <9fans@hamnavoe.com> wrote:

> Raspberry Pi 2, but has an elusive "one last bug" which I suspect has to
> do with cache or page table coherency.
>

It's still got the explicit cache management code from the old bcm, which
isn't right. There might be more.
The hardware will provide full coherency.
I've got some pi2 work to do so I'll work out the changes compared to what
I use.

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Re: [9fans] any updates on go for plan9/arm?

[lucio]

> I've got some pi2 work to do so I'll work out the changes compared to what
> I use.

Thanks, Charles, Richard and David (in reverse order of appearance),
for the effort.  It is heart warming that there is still interest in
Plan 9 and the curiously connected Go (in other words, that I'm not the
only one attracted to the platform).

I guess we'll need to wait for the critical mass or the killer app to
re-launch Plan 9 into the stratosphere :-)

In the meantime, if memory serves, there are no convenient builders for
Plan9/arm and thus no likelihood that Go will be officially released
for Plan9/arm until at least one builder is deployed.  In my
experience, David would be the best person to coordinate with, if
builders can be made available.

Lucio.

Re: [9fans] any updates on go for plan9/arm?

[Skip Tavakkolian]

> Thanks, Charles, Richard and David (in reverse order of appearance),
> for the effort.  It is heart warming that there is still interest in
> Plan 9 and the curiously connected Go (in other words, that I'm not the
> only one attracted to the platform).

Let me add my thanks as well to Go Authors and all who have made Go on
Plan 9 possible.  Go really helps Plan 9 deal with the huge number of
API's, subsystems and protocols (e.g.  OAuth2, SQL databases, HTTP/2,
etc).

-Skip

Re: [9fans] any updates on go for plan9/arm?

[David du Colombier]

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A plan9/arm builder has been already running for two months.

--
David du Colombier

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Re: [9fans] any updates on go for plan9/arm?

[lucio]

> A plan9/arm builder has been already running for two months.

I knew I'd have to qualify my statement :-)

In your opinion, will Go for plan9/arm be ready for inclusion in 1.7?

Is there any work that needs additional resources to make that
possible?

Lucio.

Re: [9fans] any updates on go for plan9/arm?

[minux]

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I just went through the patch, aside from minor cosmetic
changes, I think it's ready for inclusion into Go 1.7 if
all.bash passes. The author just has to split it up into
CLs and push to Gerrit for review.

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Re: [9fans] any updates on go for plan9/arm?

[lucio]

> I just went through the patch, aside from minor cosmetic
> changes, I think it's ready for inclusion into Go 1.7 if
> all.bash passes. The author just has to split it up into
> CLs and push to Gerrit for review.

That is great, Minux.  Thank you very much for taking the trouble.

Maybe 2016 is going to be a good year for Plan 9.  Happy new year to
all 9fans!

Lucio.

Re: [9fans] any updates on go for plan9/arm?

[Conor Williams]

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Happy neuo year bouz

Kotw

On Friday, January 1, 2016, <lucio@proxima.alt.za> wrote:

> > I just went through the patch, aside from minor cosmetic
> > changes, I think it's ready for inclusion into Go 1.7 if
> > all.bash passes. The author just has to split it up into
> > CLs and push to Gerrit for review.
>
> That is great, Minux.  Thank you very much for taking the trouble.
>
> Maybe 2016 is going to be a good year for Plan 9.  Happy new year to
> all 9fans!
>
> Lucio.
>
>
>

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