HotSpot Changes in 7u

[Andrew Hughes]

----- Original Message -----
> Hi Andrew,
> 
> cc'ing hotspot-dev
> 
> On 20/12/2012 3:11 AM, Andrew Hughes wrote:
> > Hi,
> >
> > What is the process for getting into HotSpot changes into 7u?
> > Can individual changesets be suggested and committed or do we have
> > to wait for a bulk update?  And who decides what goes in these bulk
> > updates?
> 
> Disclaimer: This is my observation not a reflection of any written
> policies etc.
> 

Understood.  We probably do need a written policy on this on the 7u
pages as it's not obvious what happens here.

Edvard?  Dalibor?

> Most (all?) Hotspot changes come in via the hsX forest (currently
> hs24
> for 7u12). Most backports come about from things "we" know we need in
> 7;
> some come from individual engineers sponsoring the jdk8 change and
> then
> the backport (I've done a few of those).
> 
> Individual changesets can be suggested, but only hsx committers can
> commit them, so you likely need a sponsor (as was likely needed for
> the
> 8/hs25 changeset anyway). The decision process is similar for 7u in
> general - we need to look at the nature of the problem and the fix
> and
> whether it is suitable for an update release (ie we won't backport
> perm-gen removal just because someone asks :) ). Backport complexity
> can
> also be an issue because of the significant changes between 7u and
> present 8 hotspot sources.

Is this the same JPRT issue as with HotSpot in OpenJDK8?  Is there any
progress on resolving this?

> 
> > We'd like to see the following changesets in 7u:
> >
> > 7170638: Use DTRACE_PROBE[N] in JNI Set and SetStatic Field.
> > http://hg.openjdk.java.net/jdk8/jdk8/hotspot/rev/75982791ddb6
> 
> This seems reasonable to me. Though I will note that a few developers
> on
> the JDK disliked the appearance of the ""**NOTICE** Dtrace support
> disabled: ..." message in their build output.
> 

I'm not aware of these messages.  Do you have a link to this issue?

> > 8000622: Forgot to hg add and check in test for JDK-7170638
> > http://hg.openjdk.java.net/jdk8/jdk8/hotspot/rev/26351ce8c4b0
> 
> Again seems reasonable to me.
> 

Yeah, it's really part of 7170638.

> > 8000780: make Zero build and run with JDK8
> > http://hg.openjdk.java.net/jdk8/jdk8/hotspot/rev/a3e2f723f2a5
> 
> And again.
> 

The alternative without this fix is that Zero doesn't currently build
on 7u.  So it's pretty necessary :-)

> I'd suggest approaching the original engineers who sponsored these
> fixes. But please bear in mind that we are hitting an extremely busy
> period with JDK 8.
> 

Ok.  This sounds like more reason to expedite the process of opening up
the process of committing HotSpot fixes to those outside Oracle.  The current
system is creating unnecessary bottlenecks.

All three of these patches relate to functionality which, I believe, is never
used by Oracle (SystemTap & Zero), but is important to Red Hat and the various
GNU/Linux distributions.

> David
> -----
> 
> > Thanks,
> 

-- 
Andrew :)

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

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