[webkit-dev] JSC String re-factorings are hosing the tree.

[Adam Roben]

On Apr 22, 2010, at 1:31 PM, Maciej Stachowiak wrote:

> On Apr 21, 2010, at 3:35 PM, Ojan Vafai wrote:
> 
>> On Wed, Apr 21, 2010 at 3:27 PM, Gavin Barraclough <barraclough at apple.com> wrote:
>> I believe a big problem that caused the extended periods of redness was the slowness of the Windows test queues.  These can lag badly behind the builds, making failures here very are easy to miss - having landed a large change, and waited to watch the waterfall stay green for an extended period of time, it was easy to be under the misapprehension that everything was okay.  Only later would I discover windows test had started to fail.  Clearly there is a lesson I've learned here, but maybe we can find some more hardware to throw at these queues, to help them avoid getting quite so far behind.
>> 
>> I also have had this problem many times. Throwing more hardware at it would be great.
>> 
>> Also, maybe we could use one of the Windows test bots for the initial trial of new-run-webkit-tests. Do we know how may cores are on those windows machines? The improvement in running the tests will be roughly proportional to the number of cores on the machine.
> 
> That will improve the time running the tests, but I think the slow thing on Windows bots is building,

It looks like test runs take about 19 minutes on the Windows Release bot, vs 11 minutes on the Leopard Release bot. That's almost twice as slow!

> and I believe that is because they are not doing parallel builds that take advantage of their multiple cores.

Yes, this is because pdevenv doesn't currently work with VC++ Express (which the bots are using to build). There might be ways to work around this, though. I filed <https://bugs.webkit.org/show_bug.cgi?id=37995> about this.

> I suspect Windows builders fall behind whenever there is a sequence of changes that each requires a long rebuild.

That might be right, though I'm having trouble finding data on this because all the recent changes that would have caused long builds broke things on one platform or the other.

-Adam