Combining client and server VM (original) (raw)

Stefan Reich stefan.reich.maker.of.eye at googlemail.com
Fri Jan 24 14:35:04 PST 2014

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.

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