RFR: 8337563: NMT: rename MEMFLAGS to MemTag [v7]

[Afshin Zafari]

On Tue, 10 Sep 2024 20:53:46 GMT, Gerard Ziemski <gziemski at openjdk.org> wrote:

>> Please review this cleanup, where we rename `MEMFLAGS` to `MemTag`.
>> 
>> `MEMFLAGS` implies that we can use more than one at the same time, but those are exclusive values, so `MemTag` is a more suitable name.
>> 
>> This fix also includes a cleanup of all the related function/template parameter names and local variable names.
>> 
>> Testing is pending...
>> 
>> Note: there is more history in old closed PRs [https://github.com/openjdk/jdk/pull/20497](https://github.com/openjdk/jdk/pull/20497) and [https://github.com/openjdk/jdk/pull/20472](https://github.com/openjdk/jdk/pull/20472)
>
> Gerard Ziemski has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Coleen's feedback

Again, if we want to replace mem type with mem tag. The regexp search for mem.*type gives this: 
---
47 results - 19 files

Source root • src/hotspot/share/gc/shared/oopStorage.hpp:
   92:   // The memory type for allocations.
  276:   // The memory type for allocations.

Source root • src/hotspot/share/nmt/mallocSiteTable.hpp:
  68:     assert(mem_tag != mtNone, "Expect a real memory type");

Source root • src/hotspot/share/nmt/memBaseline.cpp:
  64: // Sort into allocation site addresses and memory type order for baseline comparison

Source root • src/hotspot/share/nmt/memBaseline.hpp:
   56:     by_site_and_type // by call site and memory type
  206:   // Sort allocation sites in call site address and memory type order

Source root • src/hotspot/share/nmt/memReporter.cpp:
  138: void MemReporterBase::print_virtual_memory_region(const char* type, address base, size_t size) const {
  179:   // Summary by memory type
  191: void MemSummaryReporter::report_summary_of_type(MemTag mem_tag,
  280: void MemSummaryReporter::report_metadata(Metaspace::MetadataType type) const {
  343:       "Must have a valid memory type");
  522:   // Summary diff by memory type
  597: void MemSummaryDiffReporter::diff_summary_of_type(MemTag mem_tag,
  798:   MallocSiteIterator early_itr = _early_baseline.malloc_sites(MemBaseline::by_site_and_type);
  799:   MallocSiteIterator current_itr = _current_baseline.malloc_sites(MemBaseline::by_site_and_type);
  851:         // This site was originally allocated with one memory type, then released,
  852:         // then re-allocated at the same site (as far as we can tell) with a different memory type.

Source root • src/hotspot/share/nmt/memReporter.hpp:
  141:   // Report summary for each memory type

Source root • src/hotspot/share/nmt/memTracker.cpp:
  64:   // Memory type is encoded into tracking header as a byte field,

Source root • src/hotspot/share/nmt/nmtCommon.cpp:
  32: #define MEMORY_TAG_DECLARE_NAME(type, human_readable) \

Source root • src/hotspot/share/nmt/nmtCommon.hpp:
  91:     assert(tag_is_valid(mem_tag), "Invalid type (%u)", (unsigned)mem_tag);

Source root • src/hotspot/share/nmt/virtualMemoryTracker.cpp:
  297:          "Overwrite memory type for region [" INTPTR_FORMAT "-" INTPTR_FORMAT "), %u->%u.",
  425:       assert(reserved_rgn->mem_tag() == mtNone, "Overwrite memory type (should be mtNone, is: "%s")",

Source root • src/hotspot/share/nmt/virtualMemoryTracker.hpp:
  153:   // Move virtual memory from one memory type to another.
  154:   // Virtual memory can be reserved before it is associated with a memory type, and tagged
  156:   // type to specified memory type.
  394:   static bool split_reserved_region(address addr, size_t size, size_t split, MemTag mem_tag, MemTag split_type);

Source root • src/hotspot/share/nmt/vmatree.hpp:
  97:       assert(!(type == StateType::Released) || data.mem_tag == mtNone, "Released type must have flag mtNone");

Source root • src/hotspot/share/prims/whitebox.cpp:
  679: // Alloc memory using the test memory type so that we can use that to see if
  695: // Alloc memory with pseudo call stack and specific memory type.

Source root • src/hotspot/share/runtime/os.cpp:
  725:     assert(mem_tag == header->mem_tag(), "weird NMT type mismatch (new:"%s" != old:"%s")\n",

Source root • src/hotspot/share/utilities/bitMap.hpp:
  644:   // NMT memory type

Source root • src/hotspot/share/utilities/debug.cpp:
  714:     MemTracker::record_virtual_memory_type(page, mtInternal);

Source root • src/hotspot/share/utilities/growableArray.cpp:
  49:   // memory type has to be specified for C heap allocation
  50:   assert(mem_tag != mtNone, "memory type not specified for C heap object");

Source root • src/hotspot/share/utilities/resizeableResourceHash.hpp:
  33:     MemTag MEM_TYPE>
  55:       table = NEW_C_HEAP_ARRAY(Node*, table_size, MEM_TYPE);
  75:     MemTag MEM_TYPE = mtInternal,
  80:     ResizeableResourceHashtableStorage<K, V, ALLOC_TYPE, MEM_TYPE>,
  81:     K, V, ALLOC_TYPE, MEM_TYPE, HASH, EQUALS> {
  84:   using BASE = ResourceHashtableBase<ResizeableResourceHashtableStorage<K, V, ALLOC_TYPE, MEM_TYPE>,
  85:                                      K, V, ALLOC_TYPE, MEM_TYPE, HASH, EQUALS>;

Source root • src/hotspot/share/utilities/resourceHash.hpp:
   57:     MemTag MEM_TYPE,
  156:       *ptr = new (MEM_TYPE) Node(hv, key, value, *ptr);
  177:         *ptr = new (MEM_TYPE) Node(hv, key, value);
  196:         *ptr = new (MEM_TYPE) Node(hv, key);
  218:         *ptr = new (MEM_TYPE) Node(hv, key, value);

The `MemTracker::record_virtual_memory_type` can be changed to `MemTracker::record_virtual_memory_tag`

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PR Review: https://git.openjdk.org/jdk/pull/20872#pullrequestreview-2300326979
PR Review: https://git.openjdk.org/jdk/pull/20872#pullrequestreview-2300332293