RFR: 8048895: Back out JDK-8027915

[Erik Helin]

On Tuesday 01 July 2014 17:26:49 PM Mikael Gerdin wrote:
> Hi,
> 
> On Tuesday 01 July 2014 16.58.30 Erik Helin wrote:
> > Hi all,
> > 
> > the change JDK-8027915, "TestParallelHeapSizeFlags fails with unexpected
> > heap size", did not work as anticipated because of the interaction with
> > os::commit_memory on Solaris.
> > 
> > os::commit_memory takes a size_t `alignment_hint` as parameter. This
> > parameter is used differently on different operating systems: it is
> > ignored on all operating system except for Solaris. For Solaris, the
> > hint is used for selecting the large page size. If the alignment_hint is
> > smaller than the largest page size available, the hint is assumed to be
> > the *exact* page size.
> > 
> > This problem had previously been hidden because due to various
> > alignments of heap sizes and generation sizes always made sure that we
> > ended up with an alignment_hint of 4 MB by default, which also happens to
> > be a valid page size.
> > 
> > The bug can be shown to exist prior to JDK-8027915, for example by
> > running:
> > java -Xms32m -Xmx128m -XX:LargePageSizeInBytes=256m -version
> > 
> > This patch is the anti-delta of JDK-8027915 and it applied cleanly.
> > 
> > Webrev:
> > http://cr.openjdk.java.net/~ehelin/8048895/webrev.00/
> 
> The backout looks good.

Thanks!

Erik

> /Mikael
> 
> > Thanks,
> > Erik