RFR: JDK-8256155: os::Linux Populate all large_page_sizes, select smallest page size in reserve_memory_special_huge_tlbfs* [v15]

[Marcus G K Williams]

> When using LargePageSizeInBytes=1G, os::Linux::reserve_memory_special_huge_tlbfs* cannot select large pages smaller than 1G. Code heap usually uses less than 1G, so currently the code precludes code heap from using
> Large pages in this circumstance and when os::Linux::reserve_memory_special_huge_tlbfs* is called page sizes fall back to Linux::page_size() (usually 4k).
> 
> This change allows the above use case by populating all large_page_sizes present in /sys/kernel/mm/hugepages in _page_sizes upon calling os::Linux::setup_large_page_size().
> 
> In os::Linux::reserve_memory_special_huge_tlbfs* we then select the largest large page size available in _page_sizes that is smaller than bytes being reserved.

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 23 commits:

 - Merge branch 'master' into update_hlp
 - Merge branch 'master' into update_hlp
 - Remove extraneous ' from warning
   
   Signed-off-by: Marcus G K Williams <marcus.williams at intel.com>
 - Merge branch 'master' into update_hlp
 - Merge branch 'master' into update_hlp
 - Merge branch 'master' into update_hlp
 - Fix os::large_page_size() in last update
   
   Signed-off-by: Marcus G K Williams <marcus.williams at intel.com>
 - Ivan W. Requested Changes
   
   Removed os::Linux::select_large_page_size and
   use os::page_size_for_region instead
   
   Removed Linux::find_large_page_size and use
   register_large_page_sizes. Streamlined
   Linux::setup_large_page_size
   
   Signed-off-by: Marcus G K Williams <marcus.williams at intel.com>
 - Fix space format, use Linux:: for local func.
   
   Signed-off-by: Marcus G K Williams <marcus.williams at intel.com>
 - Merge branch 'update_hlp' of github.com:mgkwill/jdk into update_hlp
 - ... and 13 more: https://git.openjdk.java.net/jdk/compare/da2415fe...d73e7a4c

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

Changes: https://git.openjdk.java.net/jdk/pull/1153/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=1153&range=14
  Stats: 63 lines in 2 files changed: 24 ins; 11 del; 28 mod
  Patch: https://git.openjdk.java.net/jdk/pull/1153.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/1153/head:pull/1153

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