g******5
发帖数: 4 | 1 地点：加州湾区
JD：
We are looking for highly motivated individuals in the area of JVM
technologies and performance analysis. The lab focuses on programming
technology innovations including programming models, compilers and language
VM, and programming tools.
In particular, we are looking for candidates with strong expertise in JVM
technologies and/or in whole-system performance analysis. The position
offers a rare opportunity to influence the design of hardware and software
that are used by millions of... 阅读全帖 |
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w**z
发帖数: 8232 | 2 还是学Java 吧， 虽然facebook will try to compile php to run on VM，并不是说
直接用Java， 但Java clearly is more popular choice of programming language
than others. And more clearly, JVM is the most popular platform.
http://nerds-central.blogspot.com/2012/08/facebook-moving-to-jv
Facebook Moving To The JVM
The Big Guns get behind mlvm. I mean, BIG like GE, and Facebook!
"Are interpreters immoral?" A question I posed some months ago which might
soon become irrelevant. General purpose interpretors are about to go t... 阅读全帖 |
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k***t
发帖数: 276 | 3 Twitter is seeking experienced software engineers obsessed with making the
Java Virtual Machine (JVM) fast and scalable. We are looking for people with
experience in JVM performance profiling, garbage collection, and tuning. In
this role you will be exposed to Twitter's core application architectures
and get the chance to submerge yourself in JVM internals with the relevant
open source communities. You should be excited at the prospect of working
with our world-class engineering teams and cuttin... 阅读全帖 |
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d*2
发帖数: 2053 | 4 http://www.theregister.co.uk/2010/11/06/oracle_dueling_jvms/
Don't sweat the price. You'll pay in other ways
By Gavin Clarke in San Francisco • Get more from this author
Posted in Developer, 6th November 2010 08:00 GMT
Free whitepaper – The Register Guide to Enterprise Virtualization
QCon Oracle will deliver two Java Virtual Machines (JVMs) based on the
OpenJDK project - one free and the other paid.
That's according to Tweets pouring thick and fast from an Oracle session at
QCon San Franci... 阅读全帖 |
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s*****n
发帖数: 231 | 5 JVM技术公司在招人,有需要推荐的请联系 - Azul Systems
去年本人发过一帖，曾经置顶了几个月，收到不少简历，可是得到面试机会的只有10几
个，最终成功的只有一个，最近想起来了才发现原帖已经被删掉了（什么原因？）
公司的招聘仍在继续中，除非明确声明已经招好，此贴长期有效，请有兴趣的同学直接
发简历过来j**************[email protected], 合适的岗位我必会推荐！尤其是有JVM或者
compiler相关工作经历的同学，欢迎前来占领重要岗位！
另外，请直接发gmail联系，本人没有习惯去查站内邮件，可能会耽误事情，不过所有
问题在帖子里都能找到答案，职位的要求阿什么的，只要有耐心去看看链接里面的内容
，还是很清楚的：
http://www.azulsystems.com/about_us/careers
可以发简历给我来推荐,支持H1B，工作地点Sunnyvale, CA
请发邮件至j**************[email protected], 注意请在标题中一定明确 用英文 注明您要
申请的职位名称，邮件内部也请全部用英文， 谢谢！
祝所有找工作的同学，Good lu... 阅读全帖 |
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z****e
发帖数: 54598 | 6 各大公司一般不定制os，从jvm以下的部分
都是直接买或者直接用现成的产品
要么开源要么商用，现在做os的越来越少了
就是jvm也越来越少有公司在做了
定制的部分在jvm以上，其实企业端的定制部分会再往上一点
jvm以上的app server都是产品，然后app server这个容器内
的东西，才是真正定制的，其它都是类似的产品
品牌不一样而已，ibm的叫websphere，oracle的叫weblogic
red hat的叫jboss etc.
web公司现在如果用java的big data产品的话
从jvm以上开始定制，比如amazon和linkedin
都用jvm，但是写的java code，那就不是一回事了大相迳庭了
如果不用java的话，从os以上开始定制
或者python或者ruby或者php或者tomcat etc.
象google这种公司，则是干脆从底层自己搞
但是没有多少公司能像google这么折腾的，google有钱有能人能做事
其它公司找不到能写os的 |
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s*****n
发帖数: 169 | 7 不错。有明白人。我是开个玩笑。不过我正在做的JVM是直接读bytecode instructions
, 然后执行。不是读源程序。至于为什么要做着个东西，是和research有关。举个例子
，你想做自动测试，必须知道JVM的反馈信息。但是JVM不会给你你想要的信息因为安全
原因。Java reflection, AspectJ 也不行。
有人感兴趣，我可以open source. 合作开公司也许行。目前的版本是Java写的。的确
是在标准jvm里运行自己的jvm运行java 编译过的程序，i.e., xxx.class files。 |
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d********g
发帖数: 10550 | 8 那二爷觉得对比我给出的indeed数据，理性分析一下，Clojure、Scala这些JVM上的李
鬼们，到底是首先威胁离了JVM就活不了的Java的“backend”份额呢，还是对相对独立
完整的Python eco system造成压力？Java引以为傲的concurrency都得被这些李鬼扒了
内裤，而Python本来就不靠这个活，你要比JVM人家也有Jython来恶心你，不比JVM更是
不鸟你JVM系，压力究竟何在？
http://www.mitbbs.com/article/Programming/31288231_0.html
既然好虫都不担心发妻，二爷就不必多虑了 |
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k***r
发帖数: 4260 | 9 Yes, the IBM clearcase plugin. I don't have the error message
now but it didn't look like it failed to find it. It was a
nastier error ... I'm not sure if it runs it in its own JVM,
or in the same JVM as eclipse, though. If it's in the same JVM,
then I would be incorrect to say that that was a JVM crash. |
|
k***r
发帖数: 4260 | 10 http://benjchristensen.com/2007/02/16/32-bit-versus-64-bit-jdk-memory-
usage/
So the conclusions are:
1. 32 bit jvm can only access 2GB memory while 64 bit jvm
can access more.
2. 64 bit jvm is less memory efficient and uses 40%-50% more
memory
My question is:
1. why does 64 bit jvm uses more memory? Is it mainly wasted
on 64 bit allocation of short primitive types such as char,
int and long because twice as much memory will be allocated
and half of which wasted?
2. if I'm running a 64 bit OS, L |
|
b******y
发帖数: 9224 | 11 Oracle will deliver two Java Virtual Machines (JVMs) based on the OpenJDK
project - one free and the other paid.
That's according to Tweets pouring thick and fast from an Oracle session at
QCon San Francisco, where the database giant mostly repeated its earlier
plans for Java.
Adam Messinger, Oracle vice president of development, told QCon that Oracle
plans to offer a "premium" edition of the JDK in addition to the open-source
JDK.
Both, it seems, will be based on a converged JRockit VM and the ... 阅读全帖 |
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z****e
发帖数: 54598 | 12 这个问题问得实在是
jvm又不是apple的产品
apple才不给你搞jvm，他们在推objective c
java从诞生之初起，jvm就在不同os有自己的实现
说到底一开始所有os上的jvm都是sun的产品
比windows快一点有什么奇怪的？
就好比你在macosx上玩星际，如果这个星际运行得比windows上的星际快
不行吗？ |
|
w****w
发帖数: 521 | 13 是你没弄清楚吧？为什么不可以用他的在标准jvm里运行的jvm运行一些java小程序？
他如果牛的话，可以在他的jvm里跑他的jvm。 |
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n*w
发帖数: 3393 | 14 这个贴本来几天前就要发，当时看到有几个真正对程序语言principal有了解的人发了
不少贴。结果来了几个大坑。为了避嫌推迟到现在。
一直都scala的higher-kind type很好奇。scala是我知道两个支持higher kind type的
语言之一。另一个是haskell。有人要求microsoft在f#中加入，ms给出的答复是不会加
，因为要大改clr。
但jvm连first order都不支持。java的generic编译后要做type erasure。只是个
compiler trick。觉得scala的higher kind type要么同样也只是compile-time
checking，要么在jvm上加了东西？
找到这一段“Scala runs on the JVM, which implements a very poor type system
on its own (much poorer than the CLR). It doesn’t support type parameters
of any kind, let alone type const... 阅读全帖 |
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n*w
发帖数: 3393 | 15 这个贴本来几天前就要发，当时看到有几个真正对程序语言principal有了解的人发了
不少贴。结果来了几个大坑。为了避嫌推迟到现在。
一直都scala的higher-kind type很好奇。scala是我知道两个支持higher kind type的
语言之一。另一个是haskell。有人要求microsoft在f#中加入，ms给出的答复是不会加
，因为要大改clr。
但jvm连first order都不支持。java的generic编译后要做type erasure。只是个
compiler trick。觉得scala的higher kind type要么同样也只是compile-time
checking，要么在jvm上加了东西？
找到这一段“Scala runs on the JVM, which implements a very poor type system
on its own (much poorer than the CLR). It doesn’t support type parameters
of any kind, let alone type const... 阅读全帖 |
|
d********g
发帖数: 10550 | 16 JVM是个坎。你自己认为Clojure侵犯了Python eco system，真正Python eco system的
看到JVM都是躲着走，正如JVM系的不大待见Python。Python和C的结合更紧密效率也更
高，用不着拍JVM的马屁。二爷这个看法有一定的主观臆断了 |
|
d********g
发帖数: 10550 | 17 看看，JVM现在才这么几个李鬼就已经开始扯皮了。你不觉得JVM就好比JS，JVM众李鬼
就好比JS上框架混战吗？
一旦平台稍微成熟可以奔了，那是乌泱乌泱的人跑过来站在巨人肩膀上想摘桃子啊。这
一点JVM证明了它成熟了可以被摘了，好比JS的V8。其实我更欢迎摘Python桃子，等到
能被摘的那一天，其实也就说明了Python的性能已经牛得不行了 |
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z*******3
发帖数: 13709 | 18 是找一个c++程序员把gc, 垮平台这些给实现一遍？
还是用python那些虚拟机？或者是go这些？
理论上都可行，问题在于
用c++的，我怎么相信你这个程序员有这个水平？
你要是做不到怎么办？其次，维护谁来维护？
你造的轮子，过三个月你跟同事吵架
拍拍屁股滚蛋了，留下的烂摊子谁来收拾？
python的确实现了jvm一样的东西
问题在于，你知道python有多慢吗？
go的问题在于，网络上去哪里找支持？
遇到一个不会的东西，google都google不到的时候
我怎么办？
最后一种你把这三个凑一起用
那你知道这个学习成本有多高吗？
我知道google的backend是用c++,python和go凑成的
但是google是大公司，它有能力有财力去这么搞
其他公司，你有能力有财力么？
更不要说很多理论是google独创的，你看懂google的这些理论都需要很长时间
更不要说实现了，那怎么办？那这个时候apache有一堆的抄袭google的项目
都是jvm之上的，比如hadoop这些，这个免费的轮子你用不用？
那当然用咯，说白了就是
用jvm就是不装逼，我承认google牛，apache牛，... 阅读全帖 |
|
发帖数: 1 | 19 我不知道我理解的對不對，請高手幫忙澄清：
JVM裡內存有兩種分配方式：
1. Java object分配內存，也就是java new，首先使用手動cpu優化版本的new：
hotspot/src/cpu/x86/vm/templateTable_x86_64.cpp TemplateTable::_new()在TLAB
上分配；如果失敗，就去自動編譯的hotspot/src/share/vm/interpreter/
interpreterRuntime.cpp InterpreterRuntime::_new，這裡可能有鎖，性能低。而且
可以被GC回收，應該是managed內存。
2. JVM內部Cpp datastructure native memory allocation，一般C2 compiler做JIT時
需要分配內存，然後JVM會調用arena，arena裡面有chunkpool，裡面的chunk不夠用需
要重新分配時，會調用malloc，並用ThreadCritical的pthread_mutex_lock做保護。例
如：hotspot/src/share/vm/me... 阅读全帖 |
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n*******4
发帖数: 2285 | 20 【 以下文字转载自 JobHunting 讨论区 】
发信人: neosmith4 (天涯海客), 信区: JobHunting
标 题: 【工作机会】Equal Experts 在美东招Senior JVM Developer
发信站: BBS 未名空间站 (Sat May 14 22:39:02 2016, 美东)
大家好！
Equal Experts （EE） 是一家在欧洲名声很好的IT业咨询公司， 专招有经验IT人才。
2014年被评为全英国成长最快技术企业第二名。雇员对企业满意度很高。
http://www.businesswire.com/news/home/20141121005216/en/Equal-E
现在EE在美东招多名Senior JVM Developer， 要求如下。公司内推优先，有意请站内
联系，或电话联系本人： 631-374-4550.
谢谢！
JOB DESCRIPTION
Senior JVM Developer
Equal Experts’ agile practitioners combine technical excellence and... 阅读全帖 |
|
s*******e
发帖数: 42 | 21 He is saying running JVM on hardware -- not implementing JVM on hardware.
With O/S, it is similar to a bootloader. If you have FS support, memory
management, display drivers, etc, you may be able to compile JVM without OS. |
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t***r
发帖数: 149 | 22 请问谁知道,java 的thead.sleep()在 JVM是怎么实现的?
在linux系统中, JVM是自己program PIT/APIC 等timer devices
还是call linux 的 "nanosleep" system call. 有参考书
介绍JVM OS 层面的技术吗? 谢谢 |
|
t*********e
发帖数: 1136 | 23 If everyone uses Sun/Oracle JVM, how can it be fast? Why Oracle wants to
improve the JVM when it is free? There is no competition. There is no need.
Nobody else can improve the JVM either if it is proprietary. |
|
g*****g
发帖数: 34805 | 24 on
True, almost every production deployment uses Sun's JVM. You just can't say
your JVM is java compatible unless Oracle licenses that. That being said,
the major advancements in Java world are from open source community, like
spring and hibernate that lead to EJB3. The JDK is governed by JCP and
Oracle
cannot decide where Java should go by itself. If Oracle refuses to
collaborate
and manages a way to charge on every deployment like Oracle DB.
Harmony can call it J## or whatever and becomes the ... 阅读全帖 |
|
z****e
发帖数: 54598 | 25 一般大公司不会定制jvm下的东西
因为大公司下面一堆乱七八糟的操作系统
大部分公司都有linux/windows/unix的os
很多，开发机器现在还有macosx，所以不同平台上的兼容性是一个很大的问题
比如我们开发一般都是macosx，测试用的是windows
但是实际部署时候，生产环境用的是linux
如果不用java，那就要每次都跑生产环境上去编译
这样搞会挂，所以jvm是很重要的一个工具，没有jvm的话
很多问题搞不定啊，pc上的os跟server上的os一般来说不一样
compile once run everywhere其实对server side来说才是最重要的
mobile和pc上其实现在jdk8.0以后的版本就初步有打算搞native compiling了
javafx就有这个选择 |
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z****e
发帖数: 54598 | 26 I would say it depends on your experience and your goals. Groovy would be
the easiest transition, and if you don't already know a good dynamic
language this would be a good one. You can basically start with Java and
then "Groovify" it, and it is the only language with a joint compiler to
compile your Groovy and Java all at once. You can easily extend a Java class
with Groovy, and then extend that Groovy with Java. Try that in any other
JVM language. Given that Groovy was acquired by SpringSource... 阅读全帖 |
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w**z
发帖数: 8232 | 27 http://www.javaworld.com/article/2104441/enterprise-application
"JavaScript everywhere, and everything ported to JavaScript" -- it's either
a running joke in IT these days or a stone-cold truth. Evidence is tending
toward the latter, what with Node.js becoming a jack-of-all-trades framework
for many workloads and environments.
With Nodyn, Node.js gains yet another place it can run: the Java Virtual
Machine.
Nodyn, a project sponsored by Red Hat via its Project:Odd team, works by
leveraging two o... 阅读全帖 |
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d****i
发帖数: 4809 | 28 这句话应该改成：一切非Java的JVM语言都是纸老虎，有种的用C和C++写出一个新的类
似JVM这样的虚拟机来，不要寄生在Java的JVM上。就像伟大的有独立人格的Node一样。 |
|
x*x
发帖数: 156 | 29 请问JVM的虚拟内存到底是怎样管理的？ 为什么residential mem 用了500M, 可是jvm
能用尽 18GB？ -Xmx500M 也不行，jvm还是用了近4GB. |
|
n*******4
发帖数: 2285 | 30 【 以下文字转载自 JobHunting 讨论区 】
发信人: neosmith4 (天涯海客), 信区: JobHunting
标 题: 【工作机会】Equal Experts 在美东招Senior JVM Developer
发信站: BBS 未名空间站 (Sat May 14 22:39:02 2016, 美东)
大家好！
Equal Experts （EE） 是一家在欧洲名声很好的IT业咨询公司， 专招有经验IT人才。
2014年被评为全英国成长最快技术企业第二名。雇员对企业满意度很高。
http://www.businesswire.com/news/home/20141121005216/en/Equal-E
现在EE在美东招多名Senior JVM Developer， 要求如下。公司内推优先，有意请站内
联系，或电话联系本人： 631-374-4550.
谢谢！
JOB DESCRIPTION
Senior JVM Developer
Equal Experts’ agile practitioners combine technical excellence and... 阅读全帖 |
|
g*****g
发帖数: 34805 | 31 JVM is a great platform. But the dynamic languages running on JVM do not
have great performance either. I guess that's the price to pay for
being dynamic.
PHP, Ruby are fine choices for startups. But they eventually hit
unresolvable
language bottleneck.
way |
|
l**********r
发帖数: 4612 | 32 【 以下文字转载自 Programming 讨论区 】
发信人: linuxbeginer (linux), 信区: Programming
标 题: Java大牛推荐一本讲JVM工作原理的入门书吧？
发信站: BBS 未名空间站 (Thu Sep 5 18:00:38 2013, 美东)
比如JVM怎么IO, 调度，什么的。谢谢 |
|
d**********u
发帖数: 3371 | 33 【 以下文字转载自 Programming 讨论区 】
发信人: dingdonggulu (gulu), 信区: Programming
标 题: 问一下LeetCode JVM的Illegeal Parameter Exception
发信站: BBS 未名空间站 (Sun Feb 9 00:28:04 2014, 美东)
写代码
PriorityQueue pq = new PriorityQueue(lists.size(), new
Comparator(){ ...
这里用动态的list.size() 定义 capacity的时候出现这个编译错误 用静态书比如100
就没有错
而同样的代码在eclipse中调试就完全没有错 不管是动态还是静态
请问下这是什么原因 不同的JVM？ |
|
n*******4
发帖数: 2285 | 34 大家好！
Equal Experts （EE） 是一家在欧洲名声很好的IT业咨询公司， 专招有经验IT人才。
2014年被评为全英国成长最快技术企业第二名。雇员对企业满意度很高。
http://www.businesswire.com/news/home/20141121005216/en/Equal-E
现在EE在美东招多名Senior JVM Developer， 要求如下。公司内推优先，有意请站内
联系，或电话联系本人： 631-374-4550.
谢谢！
JOB DESCRIPTION
Senior JVM Developer
Equal Experts’ agile practitioners combine technical excellence and
business pragmatism to deliver simple bespoke software solutions to big
business problems.
We offset delivery risk by trusting only talented, highly experienced ... 阅读全帖 |
|
A*********g
发帖数: 268 | 35 谢谢JVM的以往的关注和如今亲身的参与，欢迎你！节日快乐！：）
从信里得知，JVM现在在美国学习德语，我深表敬意和钦佩，你们州的德语环境如何呢？
德国人后裔多吗？：） |
|
c*******n
发帖数: 2764 | 36 为什么要泡在baremental上？就为了一点点性能？
OS提供的诸多service是JVM的重要基础，完全脱开OS，能跑在这个JVM上的应用必定是
功能受限的 |
|
h****r
发帖数: 2056 | 37 Thanks in advance for any help!
Anybody knows how toto upgrade Oracle 9.2 enterprise server's JVM to
Jdk 1.4, so my application compiled with Jdk1.4 can be run inside Oracle
server, oracle 9.2 's installed JVM is 1.3. |
|
c*****t
发帖数: 1879 | 38 Except a few base type differences, seemed that other than unsafe code,
everything else C# has can be implemented on JVM. Those includes
delegates, attributes, etc.
It would be interesting to see codes written in C# be compiled into
JVM and uses Java APIs. |
|
c*****t
发帖数: 1879 | 39 1. to demonstrate that JVM support multiple source languages.
2. certain programming tasks are better suited with C#
3. although CLR can be portable, but only JVM is really ported to
most platforms. Java also have extensive libraries (such as graphics)
that are ready to use. Thus, people can programming in C# and take
advangage of JRE.
4. Maybe more convencing for people to go from Java to C# (or vice versa).
5. put pressure on Sun to improve Java faster.
etc etc |
|
L*******r
发帖数: 1011 | 40
JVM is not designed for this purpose. If you study the design, you will find
out.
? I like C# and I like Java. But I don't like JVM. Sorry. I really lost my
patience with SUN.
Dotnet core is portable. Both mono and dotGNU proved that. |
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e**c
发帖数: 195 | 41 The specification of JVM does not fix the shape of stack frames. That means
an implementator of JVM can decide where to put local variables, the
operand stack and state variables. Is it possible to write a Jasmin
program that allow to find out where these components are allocated in the
stack frame? |
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g**y
发帖数: 983 | 42 I found Sun JVM has 2G limit on Linux
that's a bug but SUn will not work on it
anybody knows which JVM support over 2G on Linux? |
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G*O
发帖数: 706 | 43 monitor是通过jvm instruction的两个opcode实现的
如果不调用jvm的这两个指令
是不是就没有其他办法实现synchronization，理论上可以证明嘛？ |
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Z****e
发帖数: 2999 | 44 我猜那个plug-in用了JNI，结果crash了JVM，从JNI的native library里面crash JVM还
是挺容易的，呵呵... |
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z***h
发帖数: 405 | 45 JNI非常容易crash JVM，稍微有点memory problem就有可能crash JVM
IBM JRE implementation does have some thing different with Sun JRE, JNI
implementation 里就有一些不一样。 |
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i****l
发帖数: 78 | 46 IDEA也有过同样的Issue...// http://devnet.jetbrains.net/docs/DOC-1185
On some systems the error in subject occurs when trying to run IDEA. It
happens because the native idea.exe executable built with the exe4j uses the
splash screen which loads a dll (to decode the splash image) in the address
space of the process. The jvm.dll loaded after the splash needs to allocate
the heap memory in one chunk, however the dll loaded before the jvm.dll can
fragment the address space (limited to 2GB for the 32-bit ap |
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F****n
发帖数: 3271 | 47 Could be a problem of JVM version. Did the software use its own version or
it just used whatever JVM it finds in your system? |
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i****l
发帖数: 78 | 48 昨天把系统的JVM runtime parameter修改了还是不work
今天给美国人发邮件说明了情况，他问我版本，我点击那个软件看版本，结果发现能用了
which indeed surprised me，这个JVM问题困惑了我一周！
仔细想了一下，我今天什么都没做，只是今早restart一下电脑，也许昨天修改的系统
参数生效了
谢谢大家给我的回复！ |
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k**m
发帖数: 73 | 49 jvm specification 都没讲过怎么manage heap, 我也不是开发jvm，
这从何说起呀 |
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w**z
发帖数: 8232 | 50 there are tons of JVM parameters, as far as I know, you will have to
restart JVM for them to take effect. |
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