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Published 20 hours ago • verified publisher icon brucethemoose

-Dgraal.AlwaysPreTouch

Open sydist opened this issue 3 years ago • 2 comments
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I found this; i'm not sure if it turns on automatically when you use -XX:+AlwaysPreTouch though.

sydist avatar Oct 20 '22 06:10 sydist

what does it do?

couleurm avatar Oct 20 '22 07:10 couleurm

Yes, some Dgraal arguments are seemingly duplicates of the regular OpenJDK ones and enable the same functionality, but I will double check this when I update the readme for GraalVM 22.3.0. There is probably a logging option that will tell you if pretouch is enabled or not.

All of the Dgraal arguments can be found here: https://github.com/brucethemoose/Minecraft-Performance-Flags-Benchmarks/blob/75ae126c561131888120df1b178379b67c22ef06/Flag_Dumps/All_Graal_Flags#L48

Feel free to dig through those and point out anything that looks interesting!

brucethemoose avatar Oct 20 '22 16:10 brucethemoose

@sydist See the lines here:

https://www.diffchecker.com/xkiHk4wM

Pretouch is enabled from the XX flag: [0.213s][info][gc,init] Pre-touch: Enabled

Even though the Dgraal pretouch flag defaults to false: graal.AlwaysPreTouch = false

I believe these redundant graal flags are targeted at different applications (like native image?).

brucethemoose avatar Oct 24 '22 17:10 brucethemoose

I think this can be closed since it was already tested. Though feel free to re-open or make a new issue for similar questions.

brucethemoose avatar Nov 20 '22 23:11 brucethemoose