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<div class="moz-cite-prefix">On 6/16/2016 1:33 PM, Jungwoo Ha wrote:<br>
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<div dir="ltr">I open to any different ways that is reasonable.
<div>What do you have in mind?</div>
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<br>
I wanted to look at a specific example because different<br>
solutions would apply to different situations.<br>
<br>
Generally, readability is important to us for a change<br>
like this. Just put yourself in our position. If you didn't<br>
work with CMS code, why have to look at it. Some<br>
cases, of course, will be unavoidable.<br>
<br>
Jon<br>
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<div class="gmail_extra"><br>
<div class="gmail_quote">On Wed, Jun 15, 2016 at 2:00 PM, Jon
Masamitsu <span dir="ltr"><<a moz-do-not-send="true"
href="mailto:jon.masamitsu@oracle.com" target="_blank">jon.masamitsu@oracle.com</a>></span>
wrote:<br>
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<div bgcolor="#FFFFFF" text="#000000"> Jungwoo,<br>
<br>
Could you send an example of something that would<br>
go under INCLUDE_CMS_GC? We might suggest an<br>
alternative. Having macros in the sources sometimes<br>
make it harder to read.<br>
<br>
Thanks.<span class="HOEnZb"><font color="#888888"><br>
<br>
Jon</font></span>
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<div class="h5"><br>
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<div>On 06/15/2016 11:29 AM, Jungwoo Ha wrote:<br>
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<div dir="ltr">Sounds reasonable to me.
<div>CMS uses quite a bit of common code (ParNew,
DefNew, CardTable..., JIT for wb)<br>
<div>
<div>If we have the build flag, that means we
have a macro (e.g. INCLUDE_CMS_GC).</div>
</div>
</div>
<div>It would be great if the common part code is
wrapped with the macro, external contributor can
submit without the pre-integration test.</div>
<div><br>
</div>
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<div class="gmail_extra"><br>
<div class="gmail_quote">On Wed, Jun 15, 2016 at
1:43 AM, Volker Simonis <span dir="ltr"><<a
moz-do-not-send="true"
href="mailto:volker.simonis@gmail.com"
target="_blank"><a class="moz-txt-link-abbreviated" href="mailto:volker.simonis@gmail.com">volker.simonis@gmail.com</a></a>></span>
wrote:<br>
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solid;padding-left:1ex">
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<div>On Tue, Jun 14, 2016 at 11:50 PM,
Jungwoo Ha <<a moz-do-not-send="true"
href="mailto:jwha@google.com"
target="_blank">jwha@google.com</a>>
wrote:<br>
>><br>
>> But seriously: SAP is supporting
CMS and will probably do so for quite a<br>
>> long time (simply because we do
support old Java releases for a very long<br>
>> time).<br>
>><br>
>><br>
>> Completely removing CMS from the
HotSpot code base may increase these<br>
>> support costs considerably for
us.<br>
>><br>
>> Do you plan to really delete the
sources from the repos or do you only<br>
>> plan to disable it at build time?<br>
>><br>
>><br>
>> I just don't know how this is
going to play out. I expect that the<br>
>> OpenJDK community<br>
>> will want the sources to stay.
In such a case Oracle would want them<br>
>> segregated sufficiently<br>
>> that we don't build the the
sources.<br>
>><br>
>> I think only disable it at build
time would make it easier for us and<br>
>> others to still support it in the
future. But in that case we really have to<br>
>> come up with a better development
model which would allow external<br>
>> developers to directly push CMS
changes (much like ppc64 or aarch64<br>
>> changes). Everything else would
be a real PITA.<br>
>><br>
>><br>
>> I think some model like
ppc64/aarch64 would be a good way to go.
That<br>
>> would be a<br>
>> nice side effect of this change.
You know better than I on how to get<br>
>> there.<br>
><br>
><br>
> We also need to support CMS perhaps
for a long time. I like the idea of<br>
> segregating it, and have more
external developers contribute to it.<br>
> Is there any document or can anyone
explain to me how ppc64/arch64 works?<br>
> In such case, who is responsible for
code review, building, testing, release<br>
> and so on?<br>
<br>
</div>
</div>
There's nothing special in the way the
ppc64/arch64 projects/ports<br>
work. They are integral part of
hotspot/openjdk and contributing to<br>
them is regulated by the very same rules.<br>
<br>
The only thing that we've manged to somehow
mitigate for ppc64/arch64<br>
is the pain that external (i.e. non-Oracle)
committers are still not<br>
able to directly push to the hotspot
repositories because of Oracles<br>
inability/unwillingness to open up their
infamous JPRT pre-integration<br>
test system. So as an exception to this
restriction, we are now<br>
allowed to push changes directly, if they only
touch files in<br>
hotspot/src/cpu/{ppc,aarch64}. This helps a
little bit but still not<br>
always, because many changes still touch
shared code (e.g. if they<br>
come with a regression test which is in
hotspot/test we already need<br>
an Oracle sponsor even if we're committers and
the change is fully<br>
reviewed).<br>
<br>
Building and testing the ports is the
exclusive duty of the<br>
corresponding projects. So for example we at
SAP have nightly builds<br>
of all relevant OpenJDK repositories on our
porting platforms and I'm<br>
pretty sure Red Hat has the same for aarch64.<br>
<br>
Regarding CMS, I think the idea is that the
CMS sources should be<br>
separated into their own directory with the
same relaxed checkin rules<br>
like the ones for ppc64/arch64. But again this
would only help a<br>
little bit, because there will still remain
quite some supporting CMS<br>
code in shared places (e.g. runtime,
compilers, etc..).<br>
<br>
Also, building CMS will probably be controlled
by a<br>
build-time/configure option (i.e. --use-cms)
which will be switched<br>
off by default. So it would be our duty to
build with these option<br>
turned on and test the resulting builds.<br>
<br>
Regards,<br>
Volker<br>
<br>
<br>
><br>
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-- <br>
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<div><span
style="font-size:12.8000001907349px">Jungwoo
Ha | Java Platform Team | <a
moz-do-not-send="true"
href="mailto:jwha@google.com"
target="_blank"><a class="moz-txt-link-abbreviated" href="mailto:jwha@google.com">jwha@google.com</a></a></span><br>
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-- <br>
<div class="gmail_signature" data-smartmail="gmail_signature">
<div dir="ltr">
<div><span style="font-size:12.8000001907349px">Jungwoo Ha |
Java Platform Team | <a moz-do-not-send="true"
href="mailto:jwha@google.com" target="_blank">jwha@google.com</a></span><br>
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