RFR: JDK-8188312 Use CDS if present when running the Boot JDK during build

[Claes Redestad]

On 2017-10-05 10:59, Magnus Ihse Bursie wrote:
>> How often is -Xbootclasspath/p used?
>>
>> Why not use "-XX:-VerifySharedSpaces -XX:SharedArchiveFile=local.jsa 
>> -Xshare:auto"? That way you will have the start-up benefit if possible.
>
> My worry here is that -Xshare:auto will not work correctly if 
> -Xbootclasspath/p is used. Maybe someone can guarantee that this will 
> work and convince me that it will never fail, but I don't think this 
> risk is worth the marginal gain.

Using -Xshare:auto should mean any case where a CDS archive can't be 
used (for whatever reason) should be silently ignored.  I'd be more
worried if -Xshare:on didn't fail in this case!

>
> This was supposed to be a quick and simple patch to get a small, but 
> useful improvement. It's not worth a lot of investigation or fixes, imho.

Repeating my suggestion I put as a comment in the RFE: add -Xshare:auto 
but leave out the code to dump an archive in the build (for now),
so that those of us who prepare our boot JDK to have CDS archive 
generated can get the benefit from it.

/Claes