Expand coverage of v8 testing from Node.js tree

[mhdawson]

#199 and related PR's added v8 testing on the version of v8 in the node tree (which is different from what is tested by google due to our floating patches).

We currently have a CI run that can be used to test proposed changes as well as a nightly run:
https://ci.nodejs.org/job/node-test-commit-v8-linux/

However, we don't test against all platforms/architectures. This issue is to track adding those additional combinations as need, h/w and or time allows.

Architectures we could/are testing include:

Arch	Covered	Notes
x64	Yes
Arm	No	Should work but don't have beefy enough hardware
PPC le	Yes
PPC be	Yes
s390	Yes

O/Ss that we could/are testing include:

OS	Covered	Notes
linux	Yes
mac	No	Should work but don't have enough hardware
windows	No	Needs work on build scripts
smartos	No	Needs investigation of machine issues
freebsd	No	Not tested, likely to work but did not think we needed to
AIX	No	Should work but don't have enough hardware

We also only test on x64 which we believe is ok as we think the risk of our floating patches only affecting 32 bit is low. If this proves not to be the case we can adjust.

[mhdawson]

@orangemocha, @misterdjules FYI in case you want to help out getting these running on windows/smartos

[misterdjules]

@mhdawson Thank you very much for the heads up, very much appreciated! How can I get access to the SmartOS machines that are used to run these tests?

Also, I thought we were trying to avoid floating patches on top of V8 as much as possible. Do we have a list of V8 patches that are currently floating on top of each node branch?

[jbergstroem]

As I outlined in the other issue, we need to reprovision a bigger vm to test on SmartOS. I can look at doing that in the coming week. As for windows, I reckon @joaocgreis would be the best guy to decide which machine we can use (or if we have to reprovision).

[misterdjules]

@jbergstroem Excellent, I'll let you handle this, feel free to ping me if you need anything. Thank you!

[bnoordhuis]

We also only test on x64 which we believe is ok as we think the risk of our floating patches only affecting 32 bit is low. If this proves not to be the case we can adjust.

I'd be happier if we tested both, even if we only do it initially on e.g. x86 and x86_64 Linux. V8 is largely platform agnostic but it's very much not architecture agnostic.

I'm very happy with the progress we're making, by the way!

[mhdawson]

@jbergstroem is there a x86 32 bit machine that is big enough to run the tests ?

[mhdawson]

@misterdjules "trying to avoid floating" is the key part. While we trying to keep the list small I think its quite likely we will have some small number at any one point.

[jbergstroem]

@mhdawson There's PAE and swap. Reckon both would work.

[misterdjules]

@mhdawson Is there a list of these floating patches somewhere so that we know at least how close we are from that goal?

[mhdawson]

@misterdjules I don't have the lis, @ofrobots might comment as he put together a recent PR for 5.0. I don't think we have a process for capturing them in a list but I have recent a recent one related to the test-tick-process on mac so I know there still are some. I also think that even if we reach that goal we'll likely to have temporary ones as we wait for changes to percolate into new releases (and in the LTS releases were we won't take new v8 levels)

[mhdawson]

@jbergstroem sorry I'm not quite following. I searched on the ci page for machines with PAE or swap in the name and did not find anything but maybe I'm just blind.

[misterdjules]

@mhdawson

I don't have the list, @ofrobots might comment as he put together a recent PR for 5.0. I don't think we have a process for capturing them in a list but I have recent a recent one related to the test-tick-process on mac so I know there still are some.

Sounds good. We had such a list in joyent/node and at that time I thought it was helpful. The fact that it was maintained manually was not ideal, but just having that info publicly available for everyone interested is I think valuable.

[ofrobots]

@misterdjules @mhdawson At the moment we don't have a list of floating patches. I manually look at this history of the deps/v8 directory.

I do agree that a list would be nice, however, the V8 team is talking to the LTS WG to figure out if V8 can unfreeze old branches so that Node could use those directly instead of floating patches. That might be an even nicer solution than keeping a manually updated list.