Combining client and server VM

[Stefan Reich]

Hi David!

Thanks, that was actually new to me even though I'm an avid Java fan.

It does help a bit:

-client

ImageToLua.convert: 170 ms
real    0m4.763s
user    0m1.452s
sys    0m0.124s

-server

ImageToLua.convert: 1108 ms
real    0m12.597s
user    0m7.008s
sys    0m0.388s

-client -XX:+TieredCompilation

ImageToLua.convert: 181 ms
real    0m5.686s
user    0m1.488s
sys    0m0.144s

-server -XX:+TieredCompilation

ImageToLua.convert: 398 ms
real    0m8.827s
user    0m4.572s
sys    0m0.256s

This is a run of a short program (as you can see), so we're testing
start-up time and probably only first-level compilations.
ImageToLua.convert is one of the calculating functions.

So TieredCompilation is indeed faster in startup than the pure server VM.
It still is quite a bit slower than -client, so I'm still lusting for a
perfect solution (start-up performance on part with client VM).

Cheers :)
Stefan



On Fri, Jan 24, 2014 at 9:49 PM, David Schlosnagle <schlosna at gmail.com>wrote:

> Sounds like you're describing -XX:+TieredCompilation [1], already
> available in HotSpot.
>
> [1]:
> http://docs.oracle.com/javase/7/docs/technotes/guides/vm/performance-enhancements-7.html#tieredcompilation
>
>
> On Fri, Jan 24, 2014 at 3:29 PM, Stefan Reich <
> stefan.reich.maker.of.eye at googlemail.com> wrote:
>
>> Hi there!
>>
>> Is this the official HotSpot list? Looks like it.
>>
>> I am Stefan. Here's my short bio: I was an early HotSpot adopter (before
>> its release) and now I reinvent programming (www.TinyBrain.de).
>>
>> OK, on to the topic: I'd LOVE to see the HotSpot client and server VMs
>> combined into one engine. A combination seems to me like pretty much the
>> ideal VM to have.
>>
>> It would basically start as the client VM in order to get stuff started
>> quickly, least delays possible.
>>
>> When initialisations are done, after a few seconds or so, the VM switches
>> to server mode, delivering highly-optimized code.
>>
>> I need to restart VMs a lot, but I still want maximum performance, for
>> example for GUIs. It's OK to have a slower GUI for a few seconds if you're
>> rewarded with full speed shortly after that.
>>
>> Is it possible? Shouldn't be too hard to implement, right? Anyone up for
>> it?
>>
>> Cheers,
>> Stefan
>>
>> --
>>
>> Stefan Reich
>> TinyBrain.de
>> We will beat Google to A.I.
>>
>
>