zero build slow

[Thomas Stüfe]

On Thu, Nov 23, 2017 at 10:42 AM, Severin Gehwolf <sgehwolf at redhat.com>
wrote:

> Hi Thomas,
>
> On Wed, 2017-11-22 at 17:26 +0100, Thomas Stüfe wrote:
> > Hi guys,
> >
> > thanks for your help.
> >
> > I think the reason is the combination of zero+slowdebug and the fact that
> > we run our own binaries during build (at least this is true for jmod).
> >
> > I am building on Ubuntu 16.4, "normal" machine (i7, 16G ram, ssd).
> Normally
> > my builds take ~5-10 minutes.
> >
> > My configure line in this case:
> >
> > CONFIGURE_COMMAND_LINE:=--with-boot-jdk=/shared/
> projects/openjdk/jdks/openjdk9
> > --with-debug-level=slowdebug --with-jvm-variants=zero
> > --with-native-debug-symbols=internal
> >
> > Wanted slowdebug to test something. Boot jdk is downloaded from
> > adoptopenjdk (I was lazy).
> >
> > When building (make images), top is dominated by jmod, which is taken
> from
> > the output directory, not the bootstrap vm:
> >
> > 19710 thomas    30  10 1176348  63480  15800 S 100,0  0,4   2:02.64
> > /shared/projects/openjdk/jdk-hs/output-zero/jdk/bin/jmod
> -J-XX:+UseSerialGC
> > -J-Xms32M -J-Xmx512M -J-XX:TieredStopAtLevel=1 create --module-version
> > 10-internal --target-platform linux-amd64 --module-path /sha+
> >
> > Note that my normal (non-zero) slowdebug builds are done in ~5 minutes,
> but
> > this thing here is now running for 30 minutes and not done yet. Hence my
> > assumption, that we need to run jmod from the build directory and that a
> > zero jmod in slowdebug mode is terrible.
> >
> > It probably makes sense, when I run jmod interpreted and the C++ code is
> > not optimized... Hence my original question, whether I can force the
> build
> > to use a different jmod. This would also help in cases when I am
> developing
> > and my hotspot is crashy - currently, the build does not go thru in this
> > case.
> >
> > I will retry with fastdebug to see how much faster this is.
>
> That matches my experience.
>
> FWIW, despite it being slow, running jmod using the just built JDK
> proved to be a reasonable test case for Zero issues. I've seen asserts
> being triggered or segfaults to happen during some runs indicating that
> there were issues. If you don't care about that, Erik pointed you at
> the solution :)
>
>
Yeah, sometimes I don't want that :) But I can see what you mean.

I find debugging a failing jmod during build cumbersome, you have to dig in
the make logs for the exact current dir and options it was started with. I
rather deal with a finished image where java itself asserts.

..Thomas


Cheers,
> Severin
>