RFR: 8337217: Port VirtualMemoryTracker to use VMATree [v17]

Afshin Zafari azafari at openjdk.org
Mon Jan 27 08:56:21 UTC 2025


> - `VMATree` is used instead of `SortedLinkList` in new class `VirtualMemoryTrackerWithTree`.
>  -  A wrapper/helper `RegionTree` is made around VMATree to make some calls easier.
>  -  Both old and new versions exist in the code and can be selected via `MemTracker::set_version()`
>  - `find_reserved_region()` is used in 4 cases, it will be removed in further PRs.
>  - All tier1 tests pass except one ~that expects a 50% increase in committed memory but it does not happen~  https://bugs.openjdk.org/browse/JDK-8335167.
>  - Adding a runtime flag for selecting the old or new version can be added later.
>  - Some performance tests are added for new version, VMATree and Treap, to show the idea and should be improved later. Based on the results of comparing speed of VMATree and VMT, VMATree shows ~40x faster response time.

Afshin Zafari has updated the pull request incrementally with one additional commit since the last revision:

  merge with master

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/20425/files
  - new: https://git.openjdk.org/jdk/pull/20425/files/5352894a..5429e79c

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=20425&range=16
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=20425&range=15-16

  Stats: 13437 lines in 1976 files changed: 4728 ins; 5210 del; 3499 mod
  Patch: https://git.openjdk.org/jdk/pull/20425.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20425/head:pull/20425

PR: https://git.openjdk.org/jdk/pull/20425


More information about the hotspot-dev mailing list