RFR: 8256155: Allow multiple large page sizes to be used on Linux [v36]

[Thomas Stuefe]

On Wed, 12 May 2021 22:47:15 GMT, Marcus G K Williams <mgkwill at openjdk.org> wrote:

>> Change the meaning of LargePageSizeInBytes to be the maximum large page size the JVM may use (not the only one). A default value of zero will mean to allow the JVM use large page sizes up to the system's default large page size.
>
> Marcus G K Williams has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Reuse flags & p vars, fix enclose
>   
>   Signed-off-by: Marcus G K Williams <marcus.williams at intel.com>

Hi,

we see crashes on linux ppc64 with gc/g1/TestLargePageUseForAuxMemory.java. 

#
#  Internal Error (/sapmnt/sapjvm_work/openjdk/nb/linuxppc64/jdk-dev/src/hotspot/share/utilities/globalDefinitions.cpp:370), pid=44816, tid=44821
#  assert(div != 0) failed: lcm requires positive arguments
#


Stack:


V  [libjvm.so+0xd22efc]  lcm(unsigned long, unsigned long)+0xdc
V  [libjvm.so+0xcc9430]  GCArguments::compute_heap_alignment()+0x70
V  [libjvm.so+0x490d1c]  Arguments::apply_ergo()+0x7c
V  [libjvm.so+0x186a66c]  Threads::create_vm(JavaVMInitArgs*, bool*)+0x1ec


Note that ppc64 has 64k pages. I don't have time to investigate this right now, but maybe you can reproduce the crash by faking a 64k page size in os::vm_page_size()?

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PR: https://git.openjdk.java.net/jdk/pull/1153