[crac] Integrated: 8374491: CPUFeatures: check performance regression of AVX_Fast_Unaligned_Load

[Jan Kratochvil]

On Sun, 4 Jan 2026 23:58:39 GMT, Jan Kratochvil <jkratochvil at openjdk.org> wrote:

> A regression by [JDK-8372863](https://bugs.openjdk.org/browse/JDK-8372863).
> 
> On AWS m1.small:
> 
> bin/java -XX:+ShowCPUFeatures --version
> This machine's CPU features are: -XX:CPUFeatures=0x142000070bbdf,0x380
> CPU features being used are: -XX:CPUFeatures=0x142000070bbdf,0x380
> Re-exec of java with new environment variable: GLIBC_TUNABLES=:glibc.cpu.hwcaps=,-AVX_Fast_Unaligned_Load
> This machine's CPU features are: -XX:CPUFeatures=0x142000070bbdf,0x380
> CPU features being used are: -XX:CPUFeatures=0x142000070bbdf,0x380
> openjdk 25-internal 2025-09-16
> OpenJDK Runtime Environment (fastdebug build 25-internal-adhoc.azul.crac-git)
> OpenJDK 64-Bit Server VM (fastdebug build 25-internal-adhoc.azul.crac-git, mixed mode, sharing)
> 
> That is a needless re-exec.

This pull request has now been integrated.

Changeset: 53d1ac44
Author:    Jan Kratochvil <jkratochvil at openjdk.org>
Committer: Radim Vansa <rvansa at openjdk.org>
URL:       https://git.openjdk.org/crac/commit/53d1ac44f921a330029acca99e7ab952cf355acf
Stats:     17 lines in 1 file changed: 4 ins; 6 del; 7 mod

8374491: CPUFeatures: check performance regression of AVX_Fast_Unaligned_Load

Reviewed-by: tpushkin

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PR: https://git.openjdk.org/crac/pull/283