RFR: 8256155: Allow multiple large page sizes to be used on Linux [v32]

[Thomas Stuefe]

On Fri, 7 May 2021 16:16:22 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 with a new target base due to a merge or a rebase. The pull request now contains 53 commits:
> 
>  - Remove reserve_memory_special_huge_tlbfs mods except assert
>    
>    Signed-off-by: Marcus G K Williams <marcus.williams at intel.com>
>  - Merge branch 'master' into update_hlp
>  - Merge branch 'master' into update_hlp
>  - Remove extranous vm_page_size check
>    
>    Signed-off-by: Marcus G K Williams <marcus.williams at intel.com>
>  - kstefanj review
>    
>    Signed-off-by: Marcus G K Williams <marcus.williams at intel.com>
>  - Set LargePageSizeInBytes to largepage upper limit
>    
>    Signed-off-by: Marcus G K Williams <marcus.williams at intel.com>
>  - Merge branch 'master' into update_hlp
>  - Fix merge
>    
>    Signed-off-by: Marcus G K Williams <marcus.williams at intel.com>
>  - Merge branch 'master' into update_hlp
>  - Merge branch 'master' into update_hlp
>  - ... and 43 more: https://git.openjdk.java.net/jdk/compare/0790e601...7368e7d4

Not much to add to Stefans remarks.

--Thomas

src/hotspot/os/linux/os_linux.cpp line 3765:

> 3763:     LogStream ls(lt);
> 3764:     ls.print("Available page sizes: ");
> 3765:     _page_sizes.print_on(&ls);

I'd prefer to log *all* page sizes, not the filtered list we use. Or print both, "All" and "Usable"?

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

Changes requested by stuefe (Reviewer).

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