JDK-8304954 : SegmentedCodeCache fails when using large pages
  • Type: Bug
  • Component: hotspot
  • Sub-Component: compiler
  • Affected Version: 11,17,21
  • Priority: P3
  • Status: Resolved
  • Resolution: Fixed
  • Submitted: 2023-03-27
  • Updated: 2024-05-22
  • Resolved: 2023-07-28
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JDK 17 JDK 21 JDK 22
17.0.10-oracleFixed 21.0.1Fixed 22 b09Fixed
Related Reports
Relates :  
JDK-8317831 - compiler/codecache/CheckLargePages.java fails on OL 8.8 with unexpected memory string
Description
When large pages are enabled, the VM tries to use at least one page for all code cache segments which fails if there is not enough space:

$ java -XX:+UseLargePages -XX:+SegmentedCodeCache -XX:InitialCodeCacheSize=2g -XX:ReservedCodeCacheSize=2g -XX:LargePageSizeInBytes=1g -Xlog:pagesize*=debug -version
[0.000s][debug][pagesize] Large Page sizes: 2M, 1G
[0.000s][info ][pagesize] Overriding default large page size (2M) using LargePageSizeInBytes: 1G
[0.001s][info ][pagesize] Usable page sizes: 4k, 2M, 1G
[0.003s][debug][pagesize] Commit special mapping: 0x00007fefc0000000, size=2G, page size=1G
[0.003s][info ][pagesize] CodeHeap 'non-nmethods':  min=1G max=6M base=0x00007fefffc00000 page_size=1G size=6M
Error occurred during initialization of VM
Could not reserve enough space in CodeHeap 'non-nmethods' (6144K)

We should not exit them VM but fall back to a smaller page size for the failing segment.

Thanks to Scott Oaks for reporting.
Comments
A pull request was submitted for review. URL: https://git.openjdk.org/jdk17u-dev/pull/1734 Date: 2023-09-13 12:28:10 +0000
13-09-2023
Fix request [17u] I backport this for parity with 17.0.10-oracle. Medium risk as fuddling with memory. Trivial resolve needed. Test passes.
13-09-2023
Thanks Vladimir, corrected.
07-08-2023
[~thartmann] The fix request and PR says JDK 21u but label is jdk21-fix-request
04-08-2023
A pull request was submitted for review. URL: https://git.openjdk.org/jdk21u/pull/41 Date: 2023-08-04 10:18:48 +0000
04-08-2023
Fix Request (21u): Fixes support for large pages in the code cache. The fix is low risk, applies cleanly and includes a regression test. Tested with tier 1 - 3.
04-08-2023
Changeset: cad6114e Author: Damon Fenacci <dfenacci@openjdk.org> Date: 2023-07-28 09:09:48 +0000 URL: https://git.openjdk.org/jdk/commit/cad6114e1c69bfebe5f7892c3e105b4c70d04398
28-07-2023
A pull request was submitted for review. URL: https://git.openjdk.org/jdk/pull/14903 Date: 2023-07-17 13:34:55 +0000
20-07-2023
Raising priority because this was reported again.
06-07-2023
ILW = VM exits when failing to reserve memory for code cache segment, with large pages and a large code cache size, disable segmented code cache or increase reserved code cache size = HLL = P4
27-03-2023