Default UseTLAB on Zero

[Christian Thalinger]

On Mar 5, 2012, at 1:55 PM, Gary Benson wrote:

> Hi guys,
> 
> Christian Thalinger wrote:
>> On Feb 20, 2012, at 4:47 PM, Xerxes Rånby wrote:
>>> 2012-02-20 14:26, Andrew Haley skrev:
>>>> I noticed that, on Zero, UseTLAB defaults to false, because of this
>>>> code:
>>>> 
>>>> #if !defined(COMPILER1) && !defined(COMPILER2) && !defined(SHARK)
>>>> define_pd_global(bool, BackgroundCompilation,        false);
>>>> define_pd_global(bool, UseTLAB,                      false);
>>>> ...
>>>> 
>>>> I don't understand why this is.  Surely it only pointlessly slows
>>>> down Zero.  Any ideas?
>>> 
>>> OK!
>>> 
>>> I checked the jdk6 hotspot log
>>> http://hg.openjdk.java.net/jdk6/jdk6/hotspot/annotate/20dbc199874e/src/share/vm/runtime/globals.hpp
>>> it have been turned off since the initial duke at 0 commit.
>>> 
>>> Shark have always used UseTLAB and ResizeTLAB true in its shark_globals_zero.hpp .
>>> 
>>> I think this part have simply been missed to be turned ON for Zero builds.
>> 
>> It's this push:
>> 
>> http://hg.openjdk.java.net/jdk6/jdk6/hotspot/rev/d2ede61b7a12
>> 
>> We should ask Gary why it's turned off.
> 
> I think it's a mistake, I thought it was turned on.

Andrew, do you want to turn it on for Zero?

-- Chris

> 
> Thanks,
> Gary
> 
> -- 
> http://gbenson.net/