RFR: JDK-8138864 Build with nice to lower UI impact

[Erik Joelsson]

Looks ok to me, but I suspect someone will be asking for an explicit way 
of disabling this soon.

/Erik

On 2015-10-05 11:21, Magnus Ihse Bursie wrote:
> Since building the OpenJDK is a heavy operation, the build system 
> tries to make use as of much of the system resources as possible and 
> reasonable.
>
> However, on most machines except extremely high-end, this means that 
> few resources are available for other processes. On a developer 
> machine, building means that other work can get laggy and have poor 
> response times.
>
> There is a simple remedy for this! Using "nice" to lower the priority 
> for the build process, so the build will wait for normal UI processes. 
> A single "nice" when handling the parallel targets in Init.gmk is 
> sufficient.
>
> A potential problem could be if this affects performance on dedicated 
> build servers. I have checked this on Oracle's internal build system, 
> and there were no measurable regressions. This also stands to reason, 
> since if there would be, the build server would be running other 
> processes competing with the build. On a correctly setup build server, 
> this should not be the case. And if such processes existed, it would 
> be bad anyway.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8138864
> WebRev: 
> http://cr.openjdk.java.net/~ihse/JDK-8138864-make-nice-priority/webrev.01
>
> /Magnus
>