Loading AOT alongside bytecode / caching JIT optimisations

[Gilles Duboscq]

Regarding documentation, see for example:
https://docs.oracle.com/javase/10/vm/java-hotspot-virtual-machine-performance-enhancements.htm#GUID-F33D8BD0-5C4A-4CE8-8259-FD9D73C7C7C6

As Christian said, this is a feature of the underlying JDK, it is not specific to GraalVM (although it is implemented using the Graal compiler).

 Gilles

On 02/10/2018 17:16, elias vasylenko wrote:
> Oh well that is surprising, thank you! All the documentation I've seen has
> been about the full closed-world native image AOT and I've missed all
> discussion of this entirely. I suppose it is still a preview feature
> without much documentation so I hope you'll forgive me for missing it ;)
> 
> Thanks for pointing me in the right direction, glad to hear this is here.
> 
> On Tue, 2 Oct 2018 at 14:55 Christian Thalinger <cthalinger at twitter.com>
> wrote:
> 
>> On Oct 2, 2018, at 4:22 AM, elias vasylenko <eliasvasylenko at gmail.com>
>> wrote:
>>
>> Hello,
>>
>> As I understand it Graal AOT has two main advertised advantages, which
>> appear to be orthogonal: smaller distributions and faster startup. The
>> tradeoffs made to achieve these goals are: no dynamic loading of code, no
>> dynamic recompilation, and limited reflection.
>>
>> These trade-offs make perfect sense for certain short-lifecycle
>> minimal-dependency use cases e.g. cloud/microservices/CLI. But for larger
>> applications with more traditional long-term workloads we may start to miss
>> them.
>>
>> So what if we sacrificed our ability to distribute smaller binaries and
>> focused on the singular goal of faster startup, could we eliminate the need
>> for some of these trade-offs?
>>
>> For example, if we stored out (partially?) AOT compiled code *alongside*
>>
>>
>> our original bytecode could we theoretically load it into the standard
>> GraalVM instead of SubstrateVM and enjoy fast cold-starts without giving up
>> all the bells and whistles?
>>
>> Alternatively I recall that some time ago there was a JEP which explored
>> caching JIT optimisations between runs in Hotspot, but I don't know what
>> came of it.
>>
>>
>> It’s in OpenJDK since 9:
>>
>> http://openjdk.java.net/jeps/295
>>
>> Have any of these things been revisited/explored with Graal?
>>
>> Thanks for the help, I hope these questions make sense!
>>
>>
>>