RFR: JDK-8256155: os::Linux Populate all large_page_sizes, select smallest page size in reserve_memory_special_huge_tlbfs* [v4]
Marcus G K Williams
github.com+168222+mgkwill at openjdk.java.net
Thu Dec 3 23:48:15 UTC 2020
> 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 incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains seven additional commits since the last revision:
- Adress Comments, Rework changes for PagesizeSet
Signed-off-by: Marcus G K Williams <marcus.williams at intel.com>
- JDK-8257588: Make os::_page_sizes a bitmask #1522
- Merge branch 'master' into update_hlp
- Merge branch 'update_hlp' of github.com:mgkwill/jdk into update_hlp
- Add 2M LargePages to _page_sizes
Use 2m pages for large page requests
less than 1g on linux when 1G are default
pages
- Add os::Linux::large_page_size_2m() that
returns 2m as size
- Add os::Linux::select_large_page_size() to return
correct large page size for size_t bytes
- Add 2m size to _page_sizes array
- Update reserve_memory_special methods
to set/use large_page_size based on bytes reserved
- Update large page not reserved warnings
to include large_page_size attempted
- Update TestLargePageUseForAuxMemory.java
to expect 2m large pages in some instances
Signed-off-by: Marcus G K Williams <marcus.williams at intel.com>
- Merge remote-tracking branch 'upstream/master' into update_hlp
- Add 2M LargePages to _page_sizes
Use 2m pages for large page requests
less than 1g on linux when 1G are default
pages
- Add os::Linux::large_page_size_2m() that
returns 2m as size
- Add os::Linux::select_large_page_size() to return
correct large page size for size_t bytes
- Add 2m size to _page_sizes array
- Update reserve_memory_special methods
to set/use large_page_size based on bytes reserved
- Update large page not reserved warnings
to include large_page_size attempted
- Update TestLargePageUseForAuxMemory.java
to expect 2m large pages in some instances
Signed-off-by: Marcus G K Williams <marcus.williams at intel.com>
-------------
Changes:
- all: https://git.openjdk.java.net/jdk/pull/1153/files
- new: https://git.openjdk.java.net/jdk/pull/1153/files/57e54963..0901e70e
Webrevs:
- full: https://webrevs.openjdk.java.net/?repo=jdk&pr=1153&range=03
- incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=1153&range=02-03
Stats: 2740 lines in 107 files changed: 1814 ins; 632 del; 294 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
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