RFR: JDK-8142983: Enable builds with icecc/icecream

[Magnus Ihse Bursie]

On 2015-11-13 20:55, Erik Joelsson wrote:
> We should enable builds using icecc/icecream distributed native 
> compilation. The setup is rather simple and the required changes to 
> configure are no more complex than how we currently handle ccache.
>
> I have done some experiments and it seems to be working quite well. I 
> can easily get build times of less than 2 minutes for "make 
> exploded-image" using JOBS=100 to fully saturate a couple of extra 
> hosts in the cluster. (I need to combine this with 
> --enable-javac-server to get the java compilation to not be a 
> bottleneck.)
>
> This is likely not that interesting to automated, already distributed 
> build systems, but for a developers day to day work, being attached to 
> an icecream cluster could greatly reduce local compile times.
>
> Icecream supports both linux and macosx but I have only tested this on 
> linux myself. The implementation in configure will support both gcc 
> and clang.
>
> To use the feature, given that you have icecc installed and setup to 
> join a cluster, make sure icecc is on the path and simply configure 
> with --enable-icecc and it should all work automatically. Configure 
> will generate the necessary compiler build environments that get sent 
> to the build slaves and setup the needed make variables.
>
> When enabling icecc, precompiled header is disabled. It is possible to 
> get precompiled header to work with icecc, but the performance boost 
> gets completely negated (and more) by the extra file transfer times of 
> the precompiled header file, at least in my experience.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8142983
> Webrev: http://cr.openjdk.java.net/~erikj/8142983/webrev.01/

Nice work. :)

Just a minor request:
ICECC_ENV_BUNDLE="${CONFIGURESUPPORT_OUTPUTDIR}/icecc/`${SED} -n \
         '/^creating/s/creating //p' ${icecc_create_env_log}`"

I think it would be clearer if you did the extraction as a separate 
step, e.g. something like ICECC_ENV_BUNDLE_BASENAME=`$(SED) ...`. This 
goes for both places you do this.

Apart from this, it looks fine.

/Magnus




>
> /Erik