[MERGE FOR REVIEW] HotSpot 23.25-b01 Merge

[Andrew Hughes]

----- Original Message -----
> On 09/12/2013 10:06 AM, Andrew Hughes wrote:
> > Enjoy:
> > 
> > http://cr.openjdk.java.net/~andrew/jdk6-hs23-merge/
> > 
> > Differences that remain between this and jdk7u25-b15 [0]:
> 
> Thanks for the patch and explaining the differences. All the changes
> looks sensible to me.
> 
> > * src/os/linux/vm/os_linux.cpp: keep old version of get_stack_bounds,
> > reverting 7017193 which causes
> >   performance regressions and keeping the simpler fix in [1]
> 
> Perhaps we should stick with the upstream version? Is diverging from
> upstream really worth it?

Yes [0].  I have no intention of introducing that performance regression into 6.

If we upgrade to a later HotSpot and it includes a fix for it, then we can use that.
But not in this form.

> 
> > I'll look at merging some of these minor typo changes
> > into 8 if not already present.
> 
> Please do! It will be great to have the mistakes and typos fixed upstream.
> 

Well, not exactly groundbreaking, but maybe a patch that might get approved before
the end of the world.

> One concern, though (not that it needs to be resolved right now, but I
> figured I would point it out anyway):
> 
> In current hotspot at jdk6, src/share/vm/runtime/globals.hpp contains
> this bit:
> 
> experimental(bool, EnableInvokeDynamic, false,
>             "recognize the invokedynamic instruction")
> 
> This disables JSR292 support, if I am reading this correctly. The new
> hotspot enables it:
> 
>   diagnostic(bool, EnableInvokeDynamic, true,
>           "support JSR 292 (method handles, invokedynamic,"
>           "anonymous classes")
> 
> For compatibility with Java 6, shouldn't this be kept disabled?
> 

Maybe, but either way, that's a patch to apply on top, not something to do
as part of the merge.

> Thanks,
> Omair
> --
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> 

[0] https://bugzilla.redhat.com/show_bug.cgi?id=902004#c6
-- 
Andrew :)

Free Java Software Engineer
Red Hat, Inc. (http://www.redhat.com)

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