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Hi Jon,<br>
<br>
<div class="moz-cite-prefix">On 08/22/2016 02:55 PM, Jon Masamitsu
wrote:<br>
</div>
<blockquote
cite="mid:00f50a2d-73ea-3bbb-83e2-7f64c487cd05@oracle.com"
type="cite">
<br>
<br>
On 08/22/2016 12:49 PM, sangheon wrote:
<br>
<blockquote type="cite">Hi Dima and Jon,
<br>
<br>
Let me interrupt a little bit.
<br>
<br>
As you know, we can have quite big heap alignment with large
pages enabled. And this affects to our heap ergonomics.
<br>
However, as the test case tests only whether the VM is
successfully initialized or not, I think large 'Xms' option is
enough to fix the problem.
<br>
For me, the new 'Xms/Xmx' values seem always OK to initialize
VM.
<br>
<br>
Jon, the original test failure contains '-Xms7m -Xmx9m' options.
<br>
"GC triggered before VM initialization completed. Try increasing
NewSize, current value 1280K. "
<br>
</blockquote>
<br>
If I execute "java -XX:+PrintGCDetails -XX:+UseConcMarkSweepGC
-Xms7m -Xmx9m -XX:+UseLargePages -version"
<br>
<br>
I see
<br>
<br>
[0.165s][info ][gc,heap,exit ] Heap
<br>
[0.165s][info ][gc,heap,exit ] par new generation total
2432K, used 1679K [0x00000000ff600000, 0x00000000ff8a0000,
0x00000000ff8a0000)
<br>
[0.165s][info ][gc,heap,exit ] eden space 2176K, 77% used
[0x00000000ff600000, 0x00000000ff7a3d30, 0x00000000ff820000)
<br>
[0.165s][info ][gc,heap,exit ] from space 256K, 0% used
[0x00000000ff820000, 0x00000000ff820000, 0x00000000ff860000)
<br>
[0.165s][info ][gc,heap,exit ] to space 256K, 0% used
[0x00000000ff860000, 0x00000000ff860000, 0x00000000ff8a0000)
<br>
[0.165s][info ][gc,heap,exit ] concurrent mark-sweep generation
total 5504K, used 0K [0x00000000ff8a0000, 0x00000000ffe00000,
0x0000000100000000)
<br>
<br>
which says "par new generation total 2432K" so isn't 2432K the
ParNew size?
<br>
</blockquote>
In your log, you are right.<br>
But I want to ask you whether you ran the above command on the same
or similar host machine?<br>
<br>
I got below message from same kind of machine.<br>
<br>
$ java -Xlog:gc+heap=trace -Xms7M -Xmx9M -XX:+UseConcMarkSweepGC
-XX:+UseLargePages -version<br>
<br>
[0.004s][trace][gc,heap] CMS ergo set MaxNewSize: 0<br>
[0.004s][trace][gc,heap] CMS set min_heap_size: 7340032
initial_heap_size: 7340032 max_heap: 0<br>
[0.020s][debug][gc,heap] Minimum heap 536870912 Initial heap
536870912 Maximum heap 536870912<br>
[0.020s][trace][gc,heap] 1: Minimum young 1310720 <u><b>Initial
young 1310720</b></u> Maximum young 1310720<br>
[0.020s][trace][gc,heap] Minimum old 65536 Initial old 535560192
Maximum old 535560192<br>
Java HotSpot(TM) 64-Bit Server VM warning: Failed to reserve shared
memory. (error = 1)<br>
[0.766s][debug][gc,heap] GC(0) Heap before GC invocations=0 (full
0):<br>
[0.766s][debug][gc,heap] GC(0) <b><u>par new generation total
1152K</u></b>, used 1024K [0x00000000e0000000,
0x00000000e0140000, 0x00000000e0140000)<br>
[0.766s][debug][gc,heap] GC(0) eden space 1024K, 100% used
[0x00000000e0000000, 0x00000000e0100000, 0x00000000e0100000)<br>
[0.766s][debug][gc,heap] GC(0) from space 128K, 0% used
[0x00000000e0100000, 0x00000000e0100000, 0x00000000e0120000)<br>
[0.766s][debug][gc,heap] GC(0) to space 128K, 0% used
[0x00000000e0120000, 0x00000000e0120000, 0x00000000e0140000)<br>
[0.767s][debug][gc,heap] GC(0) concurrent mark-sweep generation
total 523008K, used 0K [0x00000000e0140000, 0x0000000100000000,
0x0000000100000000)<br>
[0.767s][debug][gc,heap] GC(0) Metaspace used 3786K, capacity
4480K, committed 4480K, reserved 1056768K<br>
[0.767s][debug][gc,heap] GC(0) class space used 338K, capacity
384K, committed 384K, reserved 1048576K<br>
[0.798s][info ][gc,heap] GC(0) ParNew: 1024K->126K(1152K)<br>
[0.799s][info ][gc,heap] GC(0) CMS: 0K->738K(523008K)<br>
[0.799s][debug][gc,heap] GC(0) Heap after GC invocations=1 (full 0):<br>
[0.799s][debug][gc,heap] GC(0) par new generation total 1152K,
used 126K [0x00000000e0000000, 0x00000000e0140000,
0x00000000e0140000)<br>
[0.799s][debug][gc,heap] GC(0) eden space 1024K, 0% used
[0x00000000e0000000, 0x00000000e0000000, 0x00000000e0100000)<br>
[0.799s][debug][gc,heap] GC(0) from space 128K, 98% used
[0x00000000e0120000, 0x00000000e013f9c8, 0x00000000e0140000)<br>
[0.799s][debug][gc,heap] GC(0) to space 128K, 0% used
[0x00000000e0100000, 0x00000000e0100000, 0x00000000e0120000)<br>
[0.799s][debug][gc,heap] GC(0) concurrent mark-sweep generation
total 523008K, used 738K [0x00000000e0140000, 0x0000000100000000,
0x0000000100000000)<br>
<br>
So the ParNew size is 1152K and the initial young size is
1280K(1310720) from my log.<br>
<br>
FYI, the test machine has 524288 kB of huge page size and I think
yours has different huge page size.<br>
<br>
Thanks,<br>
Sangheon<br>
<br>
<br>
<blockquote
cite="mid:00f50a2d-73ea-3bbb-83e2-7f64c487cd05@oracle.com"
type="cite">
<br>
Jon
<br>
<br>
<blockquote type="cite">
<br>
To answer to Jon's original question, the reason of "1280k
(1310720)" is that NewSize(default value of 1363144) is aligned
to gen alignment(65536) from
GenCollectorPolicy::initialize_flags(). collectorPolicy.cpp:line
316
<br>
We resize NewSize from
GenCollectorPolicy::initialize_size_info() if needed, but it
seems like this is not the case.
<br>
<br>
Given above, the patch seems okay.
<br>
<br>
Thanks,
<br>
Sangheon
<br>
<br>
<br>
On 08/22/2016 10:37 AM, Jon Masamitsu wrote:
<br>
<blockquote type="cite">
<br>
<br>
On 08/22/2016 08:55 AM, Dmitry Fazunenko wrote:
<br>
<blockquote type="cite">Jon,
<br>
<br>
The problem could be reproduced by the following command:
<br>
<br>
#> java -Xmx3m -XX:+UseConcMarkSweepGC
-XX:+AggressiveOpts -version
<br>
Error occurred during initialization of VM
<br>
GC triggered before VM initialization completed. Try
increasing NewSize, current value 640K.
<br>
</blockquote>
<br>
I didn't notice that "-Xmx3m" was on the command line for the
original failure.
<br>
Without -Xmx3m I expected that the default heap was large and
wondered why
<br>
NewSize was so small.
<br>
<br>
Jon
<br>
<br>
<blockquote type="cite">
<br>
increasing Xmx from 3m to 4m helps:
<br>
<br>
#> java -Xmx4m -XX:+UseConcMarkSweepGC
-XX:+AggressiveOpts -version
<br>
java version "9-ea"
<br>
Java(TM) SE Runtime Environment (build 9-ea+132)
<br>
Java HotSpot(TM) 64-Bit Server VM (build 9-ea+132, mixed
mode)
<br>
<br>
I don't see anything suspicious in the GC log (attached).
<br>
<br>
There is no requirement to minimal heap required for Hotspot
to work normally, so I think the tests should not start VM
with so small heaps.
<br>
<br>
<br>
Thanks,
<br>
Dima
<br>
<br>
<br>
<br>
<br>
On 19.08.2016 21:02, Jon Masamitsu wrote:
<br>
<blockquote type="cite">Dima,
<br>
<br>
The error message I see in the logs is
<br>
<br>
GC triggered before VM initialization completed. Try
increasing NewSize, current value 1280K.
<br>
<br>
Do you know why the NewSize is so small? I ask because
I'm
<br>
not sure setting a larger heap size will always fix this
failure.
<br>
<br>
If the test is run (with the parameters that fail) and
-Xlog:gc*=trace, you might
<br>
see why the NewSize is so small (if you don't know now).
<br>
<br>
Jon
<br>
<br>
<br>
On 8/19/2016 9:02 AM, Dmitry Fazunenko wrote:
<br>
<blockquote type="cite">Hello,
<br>
<br>
May I have to get a couple of reviews for a trivial fix:
<br>
<br>
<a class="moz-txt-link-freetext" href="https://bugs.openjdk.java.net/browse/JDK-8164133">https://bugs.openjdk.java.net/browse/JDK-8164133</a>
<br>
<a class="moz-txt-link-freetext" href="http://cr.openjdk.java.net/~dfazunen/8164133/webrev.01/">http://cr.openjdk.java.net/~dfazunen/8164133/webrev.01/</a>
<br>
<br>
Two tests set very small maximum heap size, which may
cause:
<br>
starts VM with too small heap size, which might cause
<br>
Error occurred during initialization of VM
<br>
None of those tests does really require such a small
heap, so just increasing should help.
<br>
<br>
Thanks,
<br>
Dima
<br>
<br>
<br>
<br>
</blockquote>
<br>
</blockquote>
<br>
</blockquote>
<br>
</blockquote>
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</blockquote>
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