RFR: 8371948: TestStackOverflowDuringInit.java fails xss too small on linux-aarch64 [v4]

[David Holmes]

On Wed, 10 Dec 2025 03:21:58 GMT, SendaoYan <syan at openjdk.org> wrote:

>> Hi all,
>> 
>> On linux-aarch64, when page size is 64K, the minimal java thread stack size is 448K. So this PR increase the minimal java thread stack size in test/hotspot/jtreg/runtime/ClassInitErrors/TestStackOverflowDuringInit.java. Below is the calculation formula for the minimal java thread stack size:
>> 
>> 
>> page_size = 64K
>> _java_thread_min_stack_allowed = 72K
>> _stack_red_zone_size = align_up(StackRedPages * unit, page_size) = align_up(1*4K, 64K) = 64K
>> _stack_yellow_zone_size = align_up(StackYellowPages * unit, page_size) = align_up(2*4K, 64K) = 64K
>> _stack_reserved_zone_size = align_up(StackReservedPages * unit, page_size) = align_up(1*4K, 64K) = 64K
>> _stack_shadow_zone_size = align_up(StackShadowPages * unit, page_size) = align_up(25*4K, 64K) = 128K
>> _java_thread_min_stack_allowed = align_up(72K+64K+64K+64K+128K, 64K) = 448K
>> 
>> 
>> This PR add whitebox API getMinimumJavaStackSize() to the the allowd minimum java stack size, and get the allowed minimum java stack size in test/hotspot/jtreg/runtime/ClassInitErrors/TestStackOverflowDuringInit.java
>> 
>> Change has been verified locally both on linux-x64 and linux-aarch64.
>
> SendaoYan has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Use jlong instead of jint

Looking good. Just a couple of minor issues.

Thanks

src/hotspot/share/runtime/os.cpp line 2580:

> 2578: }
> 2579: 
> 2580: jlong os::get_minimum_java_stack_sizes() {

Suggestion:

jlong os::get_minimum_java_stack_size() {

src/hotspot/share/runtime/os.hpp line 394:

> 392:  public:
> 393:   // get allowed minimum java stack sizes
> 394:   static jlong get_minimum_java_stack_sizes();

Suggestion:

  // get allowed minimum java stack size
  static jlong get_minimum_java_stack_size();

test/hotspot/jtreg/runtime/memory/ReadMinimumJavaStackSize.java line 1:

> 1: /*

We don't need a test to exercise the WhiteBox API explicitly.

test/lib/jdk/test/whitebox/WhiteBox.java line 80:

> 78:   public native long getHeapSpaceAlignment();
> 79:   public native long getHeapAlignment();
> 80:   public native long  getMinimumJavaStackSize();

Suggestion:

  public native long getMinimumJavaStackSize();

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

Changes requested by dholmes (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/28352#pullrequestreview-3561172332
PR Review Comment: https://git.openjdk.org/jdk/pull/28352#discussion_r2605559716
PR Review Comment: https://git.openjdk.org/jdk/pull/28352#discussion_r2605552128
PR Review Comment: https://git.openjdk.org/jdk/pull/28352#discussion_r2605565863
PR Review Comment: https://git.openjdk.org/jdk/pull/28352#discussion_r2605566674