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From "Xiao-Feng Li" <xiaofeng...@gmail.com>
Subject Re: [performance] Startup cost is high for Harmony (HARMONY-6002)
Date Thu, 23 Oct 2008 06:21:55 GMT
On Thu, Oct 23, 2008 at 1:44 PM, Alexei Fedotov
<alexei.fedotov@gmail.com> wrote:
> Hello Wenlong,
> You have addressed a very interesting topic. Let me share few ideas
> how to approach it:
>
> 1. The first thing I would expect to understand here is why we should
> care about "Hello, World" startup. SPEC jvm [0] startup scores are
> much more tempting to approach. Then one should compare the score with
> one of our competitors. Taking into account that 300 ms = 300 context
> switches I would not say that the number itself makes me unhappy about
> Harmony speed.
>
> 2. Due to some bureaucracy the following tempting [1] idea is still
> waiting for an experienced and accurate C coder to complete:
>  * load classes into bootstrap class loader once
>  * store the internal representation of classes as a memory mapped file;
>  * next time, load the file if it exists.

Fedotov, thanks. I guess this idea can only improve the second-time
startup time? Is this be useful for SPECJVM startup score? Thanks.

Btw, your email lost bullet 3. :)

Thanks,
xiaofeng

> 4. If you don't like C, there are tunable things in a class library
> you may find using Gregory's JVMTI profiler [2].
>
> [0] http://www.spec.org/jvm2008/
> [1] a research shows +10% on "Hello, World"
> [2] two first attachments at https://issues.apache.org/jira/browse/HARMONY-4569
>
> On Thu, Oct 23, 2008 at 12:29 AM, Tim Ellison <t.p.ellison@gmail.com> wrote:
>>
>> Wenlong Li (JIRA) wrote:
>> > The startup time is long for the simple helloworld program. On a Core
>> > 2 Quad-core processor, running the simple helloworld program will take
>> > more than 300 ms.
>> > Can we reduce the startup cost?
>>
>> Yes, I hope so ... concrete suggestions or analysis of startup costs are
>> welcome.
>>
>> Regards,
>> Tim
>
>
>
> --
> With best regards,
> Alexei
>



-- 
http://xiao-feng.blogspot.com

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