Hi, On 27.05.20 18:11, Luo, Ziyi wrote:
Hi Thomas,
On 5/27/20, 3:24 AM, Thomas Schatzl wrote:
Looking forward to your review request. :) (Fwiw, at this time reviewing, or at least reviewers okay'ing it, must happen in the mailing list as per https://openjdk.java.net/contribute/).
First, my appreciation for explaining the Adaptive IHOP mechanism and the big picture in great details in the other thread, especially the additional_buffer_bytes part which I was quite confused when reading the source code. I see the need for feeding more allocation info to the Adaptive IHOP in order to achieve a more accurate estimation of both the long-term allocation rate and short-term allocation spike. In reply to two of your comments:
In email: the change imho needs to provide some measure of the spikyness of the allocation between gcs In JBS: one other improvement could be to put the old gen allocation tracking into its own class (e.g. G1OldGenAllocationTracker; which G1Policy has an instance of)
I totally agree on tracking the old gen allocation in a separate class which allows us to track and feed more allocation info to the Adaptive IHOP. That's the reason I haven't publish an RFR for JDK-8245511. The question I raised in the other email thread https://mail.openjdk.java.net/pipermail/hotspot-gc-dev/2020-May/029824.html shows that not all humongous allocations are properly tracked, which I believe can be addressed at the same time while refactoring the old gen tracking into a separate class.
Okay. :)
Without fixing the humongous tracking, my first webrev revision is premature for a review. I also agree not to overload Adaptive IHOP for tracking the humongous allocation history. Here's my current plan toward fixing JDK-8245511:
* I'll create a separate bug ID for refactoring the G1 old gen allocation tracking and providing better humongous allocation tracking and submit an RFR for that. * I'll then refactor my current patch and address comments in the JBS for JDK-8245511 based on the refactored old gen allocation tracker.
Does the plan make sense to you?
Fine with me. Still looking forward to the review :) Thanks, Thomas