RFR: 8358748: Large page size initialization fails with assert "page_size must be a power of 2" [v2]

Yagmur Eren duke at openjdk.org
Mon Jun 30 07:49:54 UTC 2025


> The VM now exits gracefully if `-XX:LargePageSizeInBytes` is set to a non power of two value, instead of asserting. After this change, `SizeTTest.java` failed because the tested values are not valid for `-XX:LargePageSizeInBytes` (`LargePageSizeInBytesConstraintFunc` returns `JVMFlag::VIOLATES_CONSTRAINT`). Therefore, I updated the test to use `NUMASpaceResizeRate`, since I believe that it only requires a flag of type `size_t`.
> 
> Before the change:
> 
> java -XX:+UseLargePages -XX:LargePageSizeInBytes=6 -version
> 
> # A fatal error has been detected by the Java Runtime Environment:
> #
> # Internal Error (workspace/open/src/hotspot/share/runtime/os.cpp:2449), pid=1885945, tid=1885946
> # assert(is_power_of_2(page_size)) failed: page_size must be a power of 2: 0x6
> 
> 
> 
> After the change:
> 
> java -XX:+UseLargePages -XX:LargePageSizeInBytes=6 -version
> 
> LargePageSizeInBytes ( 6 ) must be a power of 2
> Improperly specified VM option 'LargePageSizeInBytes=6'
> Error: Could not create the Java Virtual Machine.
> Error: A fatal exception has occurred. Program will exit.

Yagmur Eren has updated the pull request incrementally with one additional commit since the last revision:

  some fixes

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/25994/files
  - new: https://git.openjdk.org/jdk/pull/25994/files/22c33b71..f16b9a57

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=25994&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=25994&range=00-01

  Stats: 7 lines in 2 files changed: 2 ins; 3 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/25994.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/25994/head:pull/25994

PR: https://git.openjdk.org/jdk/pull/25994


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