Restrictions for lock coarsening?

[Vladimir Kozlov]

It was volano benchmark and startup benchmarks set.
For example, the regression for NetBeans startup was about 50%.

Vladimir

Tom Rodriguez wrote:
> It was definitely done as a result of benchmarking and there were 
> definitely regressions.  I don't have any information about which 
> benchmarks showed problems though.  I think it was done early enough 
> that other changes and improvements to biased locking might have 
> helped.  Maybe that's just wishful thinking on my part.
> 
> tom
> 
> On Jan 8, 2009, at 2:41 AM, Christian Thalinger wrote:
> 
>> On Tue, 2009-01-06 at 15:27 -0800, Tom Rodriguez wrote:
>>> It's been a while for me too so my answers aren't the final word but I
>>> don't think there's any implementation reason why a previously
>>> unbiasable object couldn't be converted back to a biasable one.  I
>>> think it's mainly a matter of policy and performance.  The better
>>> solution would be to remove the startup delay all together but I don't
>>> think anyone has a good idea one what it would take to do that.  The
>>> original decision was motivated by not allowing any regression, not
>>> matter how small, in the startup benchmarks.  It's possible it's not a
>>> big deal now but I don't think anyone has done the investigation to
>>> know one way or another.
>>
>> Have there been any regressions back then?  Or was the delay added
>> conservatively?
>>
>> - Christian
>>
>