On Wed, 17 Apr 2024 22:23:47 GMT, Vladimir Kozlov <k...@openjdk.org> wrote:
>> This is part of changes which try to reduce size of `nmethod` and `codeblob` >> data vs code in CodeCache. >> These changes reduced size of `nmethod` header from 288 to 232 bytes. From >> 304 to 248 in optimized VM: >> >> Statistics for 1282 bytecoded nmethods for C2: >> total in heap = 5560352 (100%) >> header = 389728 (7.009053%) >> >> vs >> >> Statistics for 1322 bytecoded nmethods for C2: >> total in heap = 8307120 (100%) >> header = 327856 (3.946687%) >> >> >> Several unneeded fields in `nmethod` and `CodeBlob` were removed. Some >> fields were changed from `int` to `int16_t` with added corresponding asserts >> to make sure their values are fit into 16 bits. >> >> I did additional cleanup after recent `CompiledMethod` removal. >> >> Tested tier1-7,stress,xcomp and performance testing. > > Vladimir Kozlov has updated the pull request with a new target base due to a > merge or a rebase. The pull request now contains eight commits: > > - Merge master > - remove trailing space > - Shuffle fields initialization > - Address comments. Used checked_cast. > - Use 16-bits types for header_size and frame_complete_offset arguments > - Union fields which usages do not overlap > - Moved some fields initialization into init_defaults() > - 8329433: Reduce nmethod header size I remove `ASSERT` blocks to address the last @dean-long comment. ------------- PR Comment: https://git.openjdk.org/jdk/pull/18768#issuecomment-2062784402
