Have you had any time to look at this?

Another use-case for this has come up regarding executing proguard actions on android internal builders. Each one uses about 1.5G, and builds that run too many in parallel on a bot tend to fail.

No, I did not have any time to look into this.

This isn't an ios-specific thing ...

I suspect this should just be a pool for all actions. I doubt this is specific to the bindings generator.

One could imagine supporting pools per action if some were cpu-intensive and others were slow and i/o-intensive or something, but I agree that just one pool would be a good start.

We need this in Fuchsia as well so I'm going to try and implement this.

Had a chat with Petr and he had a good use-case for per-action pools so I think this is OK to add.

Per-action, or for all actions? I think in the usual goma or equivalent case everyone would be better off limiting non-distributed actions to something like ninja's 2*cores default.

Maybe we need both?

For a global limit we would define a "action" tool on the toolchain since there is already a facility to have pools for tools.

If we do a per-action pool, we should replace the current "console" variable on the action with it so we don't have two ways to specify a pool. I'm guessing the best thing would be to have a "console = true" variable on the pool definition.

Per action, so:

pool("custom_pool") {
  depth = 1
}

action("action") {
  ...
  pool = ":custom_pool"
}

phosek@: that'll solve the "some actions are as heavy as linking and need to use a restricted pool issue" but won't really help the "system grinds to a halt when 200 random python actions all start grinding". I'd really like both like brettw@ suggests.

I think we need both.

OK, I'll try to address both.

FYI: change is in progress here: https://codereview.chromium.org/2926013002/

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/43ee2b1163bdee1094aac234d25f52aab9decb62

commit 43ee2b1163bdee1094aac234d25f52aab9decb62
Author: phosek <phosek@chromium.org>
Date: Thu Jun 29 01:56:01 2017

Support explicit pools in actions

This change allows explicitly specifying pools for actions.
Furthermore, it is also possible to specify a default pool for
actions as part of the toolchain. Pools can be also defined as
console ones to emulate the original console attribute behavior.

BUG= 635308 

Review-Url: https://codereview.chromium.org/2926013002
Cr-Commit-Position: refs/heads/master@{#483252}

[modify] https://crrev.com/43ee2b1163bdee1094aac234d25f52aab9decb62/tools/gn/action_target_generator.cc
[modify] https://crrev.com/43ee2b1163bdee1094aac234d25f52aab9decb62/tools/gn/action_target_generator.h
[modify] https://crrev.com/43ee2b1163bdee1094aac234d25f52aab9decb62/tools/gn/action_values.cc
[modify] https://crrev.com/43ee2b1163bdee1094aac234d25f52aab9decb62/tools/gn/action_values.h
[modify] https://crrev.com/43ee2b1163bdee1094aac234d25f52aab9decb62/tools/gn/builder.cc
[modify] https://crrev.com/43ee2b1163bdee1094aac234d25f52aab9decb62/tools/gn/builder.h
[modify] https://crrev.com/43ee2b1163bdee1094aac234d25f52aab9decb62/tools/gn/command_help.cc
[modify] https://crrev.com/43ee2b1163bdee1094aac234d25f52aab9decb62/tools/gn/docs/reference.md
[modify] https://crrev.com/43ee2b1163bdee1094aac234d25f52aab9decb62/tools/gn/function_toolchain.cc
[modify] https://crrev.com/43ee2b1163bdee1094aac234d25f52aab9decb62/tools/gn/ninja_action_target_writer.cc
[modify] https://crrev.com/43ee2b1163bdee1094aac234d25f52aab9decb62/tools/gn/ninja_action_target_writer_unittest.cc
[modify] https://crrev.com/43ee2b1163bdee1094aac234d25f52aab9decb62/tools/gn/ninja_build_writer.cc
[modify] https://crrev.com/43ee2b1163bdee1094aac234d25f52aab9decb62/tools/gn/ninja_toolchain_writer.cc
[modify] https://crrev.com/43ee2b1163bdee1094aac234d25f52aab9decb62/tools/gn/pool.cc
[modify] https://crrev.com/43ee2b1163bdee1094aac234d25f52aab9decb62/tools/gn/pool.h
[modify] https://crrev.com/43ee2b1163bdee1094aac234d25f52aab9decb62/tools/gn/toolchain.cc
[modify] https://crrev.com/43ee2b1163bdee1094aac234d25f52aab9decb62/tools/gn/toolchain.h
[modify] https://crrev.com/43ee2b1163bdee1094aac234d25f52aab9decb62/tools/gn/variables.cc
[modify] https://crrev.com/43ee2b1163bdee1094aac234d25f52aab9decb62/tools/gn/variables.h

This issue needs more action?

I don't think so, I think this could be closed.

\o/