RFR: 8364114: Test TestHugePageDecisionsAtVMStartup.java#LP_enabled fails when no free hugepage [v2]
SendaoYan
syan at openjdk.org
Sat Jul 26 03:33:35 UTC 2025
> Hi all,
>
> The test runtime/os/TestHugePageDecisionsAtVMStartup.java#LP_enabled will fails when there is no free hugepases.
> The /proc/meminfo and /sys/kernel/mm/hugepages/hugepages-*/free_hugepages says there is no free hugepage, and the JVM output also say there is available large page.
>
>
>> cat /proc/meminfo | grep -i HugePages
> AnonHugePages: 0 kB
> ShmemHugePages: 0 kB
> FileHugePages: 0 kB
> HugePages_Total: 2
> HugePages_Free: 0
> HugePages_Rsvd: 0
> HugePages_Surp: 2
> Hugepagesize: 2048 kB
>
>> ( set -x ; cat /sys/kernel/mm/hugepages/hugepages-*/free_hugepages )
> + cat /sys/kernel/mm/hugepages/hugepages-1048576kB/free_hugepages /sys/kernel/mm/hugepages/hugepages-2048kB/free_hugepages
> 0
> 0
>
> JVM output snippet from java -XX:+UseLargePages -Xlog:pagesize -version
> [0.001s][info][pagesize] Large page size (2M) failed sanity check, checking if smaller large page sizes are usable
> [0.001s][warning][pagesize] UseLargePages disabled, no large pages configured and available on the system.
>
>
> The JVM can not use large page when there is no available large page on system, it's not a JVM bug. So I think it's not suitable to report test failure, but report SkippedException.
>
> Change has been verified locally, test report SkippedException on the system without free hugepage, the test passes on the system with free hugepage. Test-fix only, risk is low.
SendaoYan has updated the pull request incrementally with one additional commit since the last revision:
Remove @build jtreg.SkippedException
-------------
Changes:
- all: https://git.openjdk.org/jdk/pull/26480/files
- new: https://git.openjdk.org/jdk/pull/26480/files/52bbdd9a..b2c096fa
Webrevs:
- full: https://webrevs.openjdk.org/?repo=jdk&pr=26480&range=01
- incr: https://webrevs.openjdk.org/?repo=jdk&pr=26480&range=00-01
Stats: 3 lines in 1 file changed: 0 ins; 3 del; 0 mod
Patch: https://git.openjdk.org/jdk/pull/26480.diff
Fetch: git fetch https://git.openjdk.org/jdk.git pull/26480/head:pull/26480
PR: https://git.openjdk.org/jdk/pull/26480
More information about the hotspot-runtime-dev
mailing list