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<div class="moz-cite-prefix">On 6/3/2015 2:32 AM, Volker Simonis
wrote:<br>
</div>
<blockquote
cite="mid:CA+3eh107pXRT-x-D3Nre+SYjfh9mfqgxzmj8oZcH=TgbSHmxZA@mail.gmail.com"
type="cite">
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<div>Hi Jeremy,<br>
<br>
</div>
thanks for your answer. Maybe you misunderstood Ivan but it
is definitely his and our (i.e. SAP's) intention to make
this part of the OpenJDK.<br>
<br>
</div>
I can also fully understand the pains you have with
integrating changes into the HotSpot. We've gone through this
painful process with our ppc64 port a year ago but we think it
will finally pay off. After all you (i.e. Google) used it as
the base for your ppc64le port (Alexander Smundak contributed
most of the LE-specific changes).<br>
<br>
We're facing the exactly same problems regarding the support
of proprietary changes in a downstream version of the OpenJDK.
That was actually the main reason why we started contributing
to the OpenJDK. What we want to kindly ask you is to make your
changes and extensions more transparently visible to the
community if you intend to integrate them into the OpenJDK. If
Hiroshi had posted his changes directly to the hotspot mailing
lists instead of sending them privately to Jon I'm pretty sure
we would have picked them up. And maybe together we would have
managed to push them through (we have some reviewers as well
:). After all, there are already quite a lot of features in
the OpenJDK which are supported and maintained by the
community (i.e. RedHat, IBM, SAP, ...) and not by Oracle. <br>
<br>
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<br>
Volker,<br>
<br>
With regards to integrating such a change as discussed here, how do
you see "supported and maintained by the community" working? I
really don't know what to expect.<br>
<br>
Jon<br>
<br>
PS. I actually never saw the patch from Hiroshi.<br>
<blockquote
cite="mid:CA+3eh107pXRT-x-D3Nre+SYjfh9mfqgxzmj8oZcH=TgbSHmxZA@mail.gmail.com"
type="cite">
<div dir="ltr">I don't have much experience with other Open Source
projects, but with OpenJDK and especially HotSpot it's pretty
pointless to try to contribute something by writing mails like
"..I've implemented this cool feature XXX. If somebody is
interested I can post more details..". You'll almost never get
any feedback to such kind of requests. You'll at least have to
post a complete buildabel and runnable patch against the head
revision. I know that's a lot of overhead and we're having this
very same discussion if it is worth doing it nearly every day
for most of the features/additions we are implementing.
Nevertheless, I think it is worth doing it although it sometimes
may take years until you get your changes back in the version
you are using productively.<br>
<div><br>
</div>
<div>So coming back to Ivan's initial request, we would kindly
ask you to just publish your changes in their current form
against your current version (8u45 or whatsoever). We'll take
a look at them an may invest some time and effort (also
jointly with you if desired) to forward port them to 9 and
propose them for integration into the head revision if that
makes sense. Thus that sound reasonable to you?<br>
</div>
<div><br>
</div>
<div>Thank you and best regards,<br>
</div>
<div>Volker<br>
<br>
</div>
</div>
<div class="gmail_extra"><br>
<div class="gmail_quote">On Tue, Jun 2, 2015 at 5:00 PM, Jeremy
Manson <span dir="ltr"><<a moz-do-not-send="true"
href="mailto:jeremymanson@google.com" target="_blank">jeremymanson@google.com</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div dir="ltr">We'd much rather it be part of OpenJDK,
because it is large and fairly complicated, so that would
save us time and energy forward porting it every year or
so. It's pretty large (for 8u45, it is a 2600 line change
and touches 20 files), so it tends to be a lengthy and
complicated forward port. We would much rather spend that
time doing something more interesting.
<div><br>
</div>
<div>Just posting an updated patch whenever we need to
update it would be a little annoying (although not
impossible).
<div><br>
</div>
<div>Hiroshi Yamauchi tried to offer it to (I think it
was) Jon Masamitsu a few years ago, and Jon didn't
know anyone with the bandwidth to review it. (It was
around the same time we contributed the parallel
initial mark). I believe that was when CMS was
unowned for a while. Perhaps there's a different
story now? Oracle volunteers?
<div>
<div><br>
<div>(Procedural: One problem is that Hotspot
reviews have to go through someone at Oracle.
We had it written by an OpenJDK author and
reviewed by a reviewer. We've been using it in
production for years without too many headaches
(although we have yet to inflict^Wlaunch 8u45,
which has the latest updates, widely). I
totally understand that Oracle folks are the
ones who have to pay the price for a bad
check-in, but it's a pretty big hurdle for us.)</div>
<span class="HOEnZb"><font color="#888888">
<div><br>
</div>
<div>
<div>
<div>Jeremy<br>
</div>
</div>
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</font></span></div>
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<div class="HOEnZb">
<div class="h5">
<div class="gmail_extra"><br>
<div class="gmail_quote">On Tue, Jun 2, 2015 at 6:12
AM, Galkin, Ivan <span dir="ltr"><<a
moz-do-not-send="true"
href="mailto:ivan.galkin@sap.com"
target="_blank">ivan.galkin@sap.com</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div link="blue" vlink="purple" lang="EN-GB">
<div>
<p class="MsoNormal"><span lang="DE">Hi,</span></p>
<p class="MsoNormal"><span lang="DE"> </span></p>
<p class="MsoNormal">in the thread „JEP 248:
Make G1 the Default Garbage Collector” [1]
there is an email from Jeremy Manson, who
mentions the enhancements made by Google to
improve CMS.</p>
<p class="MsoNormal">Especially the
parallelizing of full compaction is a great
improvement and we at SAP see the strong
demand of it.</p>
<p class="MsoNormal"> </p>
<p>@Jeremy: Are these changes published
somewhere? May we have insight into the
diffs you've made? We could collaborate in
order to try to bring your changes into
OpenJDK.</p>
<p> </p>
<p>Kind regards and thank you in advance,</p>
<p>Ivan</p>
<p> </p>
<p>[1] <a moz-do-not-send="true"
href="http://mail.openjdk.java.net/pipermail/hotspot-dev/2015-June/018740.html"
target="_blank">
http://mail.openjdk.java.net/pipermail/hotspot-dev/2015-June/018740.html</a></p>
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