RFR: 8319795: Static huge pages are not used for CodeCache [v6]

[Evgeny Astigeevich]

On Wed, 29 Nov 2023 21:27:59 GMT, Thomas Stuefe <stuefe at openjdk.org> wrote:

> Sorry, no time to look at this in depth atm. This is suddenly a large patch, not sure why. I'd suggest to keep refactoring for a different RFE.

@tstuefe No worries. I'll do refactoring in different RFEs.
I made a fix which allows 1g pages for non-segmented CodeCache and 2M pages for segmented CodeCache.
Anyway 1g pages are not practical for segmented CodeCache because the size of CodeCache is limited to 2g. Also having 1g non-nmethod code heap makes no sense. I'll add a test tomorrow.


$ cat /proc/meminfo
...
HugePages_Total:     200
HugePages_Free:      200
HugePages_Rsvd:        0
HugePages_Surp:        0
Hugepagesize:       2048 kB
Hugetlb:        10895360 kB
DirectMap4k:      778136 kB
DirectMap2M:    33562624 kB
DirectMap1G:    363855872 kB

$ ./java -XX:+PrintCodeCache -XX:+UseLargePages -Xlog:pagesize=debug -Xmx1g -Xms1g -XX:+UseLargePages -XX:LargePageSizeInBytes=1g -version
[0.001s][info][pagesize] Static hugepage support:
[0.001s][info][pagesize]   hugepage size: 2M
[0.001s][info][pagesize]   hugepage size: 1G
[0.001s][info][pagesize]   default hugepage size: 2M
[0.001s][info][pagesize] Transparent hugepage (THP) support:
[0.001s][info][pagesize]   THP mode: madvise
[0.001s][info][pagesize]   THP pagesize: 2M
[0.001s][info][pagesize] Overriding default large page size (2M) using LargePageSizeInBytes: 1G
[0.001s][info][pagesize] UseLargePages=1, UseTransparentHugePages=0
[0.001s][info][pagesize] Large page support enabled. Usable page sizes: 4k, 2M, 1G. Default large page size: 1G.
[0.002s][debug][pagesize] Commit special mapping: 0x00007ff03ca00000, size=240M, page size=2M
[0.002s][info ][pagesize] CodeHeap 'non-nmethods':  min=4M max=10M base=0x00007ff043c00000 size=10M page_size=2M
[0.003s][info ][pagesize] CodeHeap 'profiled nmethods':  min=4M max=114M base=0x00007ff03ca00000 size=114M page_size=2M
[0.005s][info ][pagesize] CodeHeap 'non-profiled nmethods':  min=4M max=116M base=0x00007ff044600000 size=116M page_size=2M
[0.064s][debug][pagesize] Commit special mapping: 0x00000000c0000000, size=1G, page size=1G
[0.064s][info ][pagesize] Heap:  min=1G max=1G base=0x00000000c0000000 size=1G page_size=1G
[0.064s][debug][pagesize] Commit special mapping: 0x00007ff03a600000, size=2M, page size=2M
[0.064s][info ][pagesize] Block Offset Table: req_size=2M req_page_size=2M base=0x00007ff03a600000 size=2M page_size=2M
[0.064s][debug][pagesize] Commit special mapping: 0x00007ff03a200000, size=2M, page size=2M
[0.064s][info ][pagesize] Card Table: req_size=2M req_page_size=2M base=0x00007ff03a200000 size=2M page_size=2M
[0.064s][debug][pagesize] Commit special mapping: 0x00007ff039000000, size=16M, page size=2M
[0.064s][info ][pagesize] Mark Bitmap: req_size=16M req_page_size=2M base=0x00007ff039000000 size=16M page_size=2M
openjdk version "22-internal" 2024-03-19
OpenJDK Runtime Environment (fastdebug build 22-internal-adhoc.eastig.jdk)
OpenJDK 64-Bit Server VM (fastdebug build 22-internal-adhoc.eastig.jdk, mixed mode, sharing)
CodeHeap 'non-profiled nmethods': size=118784Kb used=16Kb max_used=16Kb free=118767Kb
 bounds [0x00007ff044600000, 0x00007ff044a00000, 0x00007ff04ba00000]
CodeHeap 'profiled nmethods': size=116736Kb used=120Kb max_used=120Kb free=116615Kb
 bounds [0x00007ff03ca00000, 0x00007ff03ce00000, 0x00007ff043c00000]
CodeHeap 'non-nmethods': size=10240Kb used=3690Kb max_used=3701Kb free=6549Kb
 bounds [0x00007ff043c00000, 0x00007ff044000000, 0x00007ff044600000]
 total_blobs=752 nmethods=72 adapters=591
 compilation: enabled
              stopped_count=0, restarted_count=0
 full_count=0

$ ./java -XX:+PrintCodeCache -XX:+UseLargePages -Xlog:pagesize=debug -Xmx1g -Xms1g -XX:+UseLargePages -XX:ReservedCodeCacheSize=1G -XX:InitialCodeCacheSize=1G -XX:LargePageSizeInBytes=1g -version
[0.001s][info][pagesize] Static hugepage support:
[0.001s][info][pagesize]   hugepage size: 2M
[0.001s][info][pagesize]   hugepage size: 1G
[0.001s][info][pagesize]   default hugepage size: 2M
[0.001s][info][pagesize] Transparent hugepage (THP) support:
[0.001s][info][pagesize]   THP mode: madvise
[0.001s][info][pagesize]   THP pagesize: 2M
[0.001s][info][pagesize] Overriding default large page size (2M) using LargePageSizeInBytes: 1G
[0.001s][info][pagesize] UseLargePages=1, UseTransparentHugePages=0
[0.001s][info][pagesize] Large page support enabled. Usable page sizes: 4k, 2M, 1G. Default large page size: 1G.
[0.002s][debug][pagesize] Commit special mapping: 0x00007f3680000000, size=1G, page size=1G
[0.002s][info ][pagesize] CodeCache:  min=1G max=1G base=0x00007f3680000000 size=1G page_size=1G
[0.002s][debug][pagesize] Commit special mapping: 0x00007f370b600000, size=8M, page size=2M
[0.435s][debug][pagesize] Commit special mapping: 0x00000000c0000000, size=1G, page size=1G
[0.435s][info ][pagesize] Heap:  min=1G max=1G base=0x00000000c0000000 size=1G page_size=1G
[0.435s][debug][pagesize] Commit special mapping: 0x00007f36fae00000, size=2M, page size=2M
[0.435s][info ][pagesize] Block Offset Table: req_size=2M req_page_size=2M base=0x00007f36fae00000 size=2M page_size=2M
[0.435s][debug][pagesize] Commit special mapping: 0x00007f36faa00000, size=2M, page size=2M
[0.435s][info ][pagesize] Card Table: req_size=2M req_page_size=2M base=0x00007f36faa00000 size=2M page_size=2M
[0.435s][debug][pagesize] Commit special mapping: 0x00007f36f9800000, size=16M, page size=2M
[0.435s][info ][pagesize] Mark Bitmap: req_size=16M req_page_size=2M base=0x00007f36f9800000 size=16M page_size=2M
openjdk version "22-internal" 2024-03-19
OpenJDK Runtime Environment (fastdebug build 22-internal-adhoc.eastig.jdk)
OpenJDK 64-Bit Server VM (fastdebug build 22-internal-adhoc.eastig.jdk, mixed mode, sharing)
CodeCache: size=1048576Kb used=3884Kb max_used=3884Kb free=1044691Kb
 bounds [0x00007f3680000000, 0x00007f36c0000000, 0x00007f36c0000000]
 total_blobs=752 nmethods=72 adapters=591
 compilation: enabled
              stopped_count=0, restarted_count=0
 full_count=0

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

PR Comment: https://git.openjdk.org/jdk/pull/16582#issuecomment-1832904229