code review 132350043: runtime: fix build

runtime: fix build

'range hash' makes a copy of the hash array in the stack, creating
a very large stack frame. It's just the right amount that it
uses most but not all of the total stack size. If you have a lot
of environment variables, like the builders, then this is too
much and the g0 stack runs out of space.

[rsc, 2014-08-28 15:45:29]

Hello bradfitz (cc: golang-codereviews@googlegroups.com),

I'd like you to review this change to
https://code.google.com/p/go/

[rsc, 2014-08-28 15:45:35]

*** Submitted as https://code.google.com/p/go/source/detail?r=2b43b05b5dd9 ***

runtime: fix build

'range hash' makes a copy of the hash array in the stack, creating
a very large stack frame. It's just the right amount that it
uses most but not all of the total stack size. If you have a lot
of environment variables, like the builders, then this is too
much and the g0 stack runs out of space.

TBR=bradfitz
CC=golang-codereviews
https://codereview.appspot.com/132350043

[crawshaw, 2014-08-28 15:51:42]

LGTM

[bradfitz, 2014-08-28 15:59:07]

LGTM

nice



On Thu, Aug 28, 2014 at 8:45 AM, <rsc@golang.org> wrote:

> Reviewers: bradfitz,
>
> Message:
> Hello bradfitz (cc: golang-codereviews@googlegroups.com),
>
> I'd like you to review this change to
> https://code.google.com/p/go/
>
>
> Description:
> runtime: fix build
>
> 'range hash' makes a copy of the hash array in the stack, creating
> a very large stack frame. It's just the right amount that it
> uses most but not all of the total stack size. If you have a lot
> of environment variables, like the builders, then this is too
> much and the g0 stack runs out of space.
>
> Please review this at https://codereview.appspot.com/132350043/
>
> Affected files (+1, -1 lines):
>   M src/pkg/runtime/iface.go
>
>
> Index: src/pkg/runtime/iface.go
> ===================================================================
> --- a/src/pkg/runtime/iface.go
> +++ b/src/pkg/runtime/iface.go
> @@ -427,7 +427,7 @@
>  }
>
>  func iterate_itabs(fn func(*itab)) {
> -       for _, h := range hash {
> +       for _, h := range &hash {
>                 for ; h != nil; h = h.link {
>                         fn(h)
>                 }
>
>
>