Remove the stack size limit from the posix worker pool.

Remove the stack size limit from the posix worker pool.

We don't use one on windows either, and e.g. for running V8 compile
jobs, we need a higher stack size limit than we currently have. Instead
of guessing a value, let's just use the default.

BUG=464538
R=mark@chromium.org,rmcilroy@chromium.org

Committed: https://crrev.com/c704e16994249b75baa904c14dd0c0e62e8e60ef
Cr-Commit-Position: refs/heads/master@{#319615}

[rmcilroy, 2015-03-09 10:22:04]

Seems reasonable to me.  As I understand it, most OSs don't commit memory for
the stack until it is first touched - therefore this shouldn't actually affect
memory usage in most circumstances unless we do something like
zero-intialization of the whole reserved stack during initialization.

Would it be worth adding a (slightly larger) limit for debug builds so that we
can track regressions?

[jochen (gone - plz use gerrit), 2015-03-09 10:23:31]

On 2015/03/09 at 10:22:04, rmcilroy wrote:
> Seems reasonable to me.  As I understand it, most OSs don't commit memory for
the stack until it is first touched - therefore this shouldn't actually affect
memory usage in most circumstances unless we do something like
zero-intialization of the whole reserved stack during initialization.
> 
> Would it be worth adding a (slightly larger) limit for debug builds so that we
can track regressions?

not sure I understand?

[Mark Mentovai, 2015-03-09 13:07:02]

The smaller limit also reduced address space fragmentation, which still might be
a problem on 32-bit platforms. But if you want to try this, LGTM.

[jochen (gone - plz use gerrit), 2015-03-09 13:08:36]

The CQ bit was checked by jochen@chromium.org

[jochen (gone - plz use gerrit), 2015-03-09 13:08:37]

let's give it a try. if nothing bad turns up after a week, i'll turn on the v8
part again

[commit-bot: I haz the power, 2015-03-09 13:08:47]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/992623002/1

[commit-bot: I haz the power, 2015-03-09 13:11:20]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-03-09 13:11:49]

Patchset 1 (id:??) landed as
https://crrev.com/c704e16994249b75baa904c14dd0c0e62e8e60ef
Cr-Commit-Position: refs/heads/master@{#319615}