RFR: JDK-8056053: Disable HOTSPOT_BUILD_JOBS when building with configure

[Daniel D. Daugherty]

On 8/27/14 6:53 AM, Erik Joelsson wrote:
> Thanks David and Magnus for the reviews!
>
> Now for pushing this. The changes in root and hotspot need to go 
> together. They should not affect the standalone hotspot build, nor the 
> resulting built bits. I think it is safe to push both to jdk9/hs-rt as 
> it would not affect testing compatibility with the promoted jdk build. 
> Is it ok to do so?

Not only OK, but also the preferred way to go! Alejandro prefers that
HotSpot makefile changes come up through HotSpot repos so we don't
get any surprises...

Dan


>
> /Erik
>
>
> On 2014-08-26 12:53, Erik Joelsson wrote:
>> Hello,
>>
>> Please review this proposed fix for the Hotspot build.
>>
>> In the new jdk9 build, we utilize the gnu make job server, which 
>> automatically makes sure the -j flag gets propagated and shared 
>> between all recursive make calls. In the hotspot build, this gets 
>> overridden by the HOTSPOT_BUILD_JOBS variable. Configure estimates a 
>> reasonable number of parallel make jobs into the JOBS variable, which 
>> gets propagated to the HOTSPOT_BUILD_JOBS variable. This used to work 
>> well enough, but in the new build, the hotspot build is happening 
>> concurrently with other parts of the build and the consequence is 
>> that the hotspot build gets JOBS number of jobs and the rest of the 
>> build also gets JOBS number of jobs, all of which are used at the 
>> same time. We would like the whole build to share in the same job pool.
>>
>> To fix this, the setting of -j$(HOTSPOT_BUILD_JOBS) needs to be made 
>> conditional and we need to add .NOTPARALLEL: to a number of makefiles 
>> in hotspot that currently can't handle being executed in parallel. 
>> Lastly, the + sign must be added first to recipe lines that call make 
>> recursively but are not explicitly using the MAKE variable directly. 
>> The result will be that the active -j flag in the root makefiles will 
>> just automatically propagate down to the hotspot makefiles.
>>
>> Bug: https://bugs.openjdk.java.net/browse/JDK-8056053
>> Webrev: http://cr.openjdk.java.net/~erikj/8056053/webrev.01/
>>
>> /Erik
>