Experience of adding JDK21 virtual thread support to a DB application

[Alan Bateman]

On 21/06/2024 16:57, Matthew Swift wrote:
> :
>
> These results are on my laptop (Intel i9-13900H with 10 cores, Linux 
> 6.5, JDK 21.0.3), but we see similar regressions on larger older 
> machines in our labs. Also worthy of note is that the context 
> switching rate increases from around 180K/s when using synchronized() 
> to 300K/s when using ReentrantLock. I know that ReentrantLock is 
> supposed to be a little bit less efficient in highly contended 
> situations, but I was surprised by an 8-10% impact. Is that expected?

One thing that might be part of this is that a contented monitor enter 
does a small amount of spinning. Sergey Kuksenko may have some comments 
on this as he has some proposals on this at one point.

-Alan