On Fri, 26 Apr 2024 21:36:50 GMT, Vladimir Kozlov <k...@openjdk.org> wrote:
>> Move immutable nmethod's data from CodeCache to C heap. It includes >> `dependencies, nul_chk_table, handler_table, scopes_pcs, scopes_data, >> speculations, jvmci_data`. It amounts for about 30% (optimized VM) of space >> in CodeCache. >> >> Use HotSpot's `os::malloc()` to allocate memory in C heap for immutable >> nmethod's data. Bail out compilation if allocation failed. >> >> Shuffle fields order and change some fields size from 4 to 2 bytes to avoid >> nmethod's header size increase. >> >> Tested tier1-5, stress,xcomp >> >> Our performance testing does not show difference. >> >> Example of updated `-XX:+PrintNMethodStatistics` output is in JBS comment. > > src/hotspot/share/code/nmethod.cpp line 117: > >> 115: result = static_cast<T>(thing); \ >> 116: assert(static_cast<int>(result) == thing, "failed: %d != %d", >> static_cast<int>(result), thing); >> 117: > > I replaced `checked_cast<>()` with this macro because of next issues: > - The existing assert points to `utilities/checkedCast.hpp` file where this > method is located and not where failed cast. It does not help when it is used > several times in one method (for example, in `nmethod()` constructors). > - The existing assert does not print values I thought @kimbarrett had a draft PR to address the error reporting issue, but I can't seem to find it. To solve the general problem, I think we need a version of vmassert() that takes `char* file, int lineno` as arguments, and a macro wrapper for checked_cast() that passes `__FILE__` and `__LINEN__` from the caller. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/18984#discussion_r1581628786
