Small change triggers 8990 file compiling?

[Alan Bateman]

On 12/10/2012 03:57, Weijun Wang wrote:
> Hi All
>
> I'm using the new build on a Ubuntu 12.04 64 bit. Configure runs ok, 
> and make runs ok. Now I have a good build output directory. Running 
> make again costs no time at all.
>
> Then I qpush a mq patch, which only touches 30 or so files deep inside 
> src/share/classes/com/sun/security and src/share/classes/sun/security 
> of the jdk repo, and running make shows
>
>    Compiling 8990 files for BUILD_JDK
>
> and a while bunch of other c files which costs 00:01:20.
>
> Is that an expected behavior?
My experience with the new build is that it is really fast for doing the 
initial build, really fast at doing incremental builds after touching 
native code, but not so fast when touching java classes. Those of us 
used to the old build system know the make files to run and are used to 
incremental builds that take only a few seconds. I realize this isn't 
really a fair comparison as the old build system doesn't track 
dependencies and is very unreliable.

You might want to --enable-sjavac which is the "smart javac". I saw a 
mail from Magnus recently that said this isn't enabled by default as 
it's not completely stable yet. It's been working well for me and I see 
a bunch of changes going in from Fredrik that suggests to me that it is 
improving by the day. Anyway, from trying sjavac is that it seems to get 
us into the right ballpark.

-Alan