WL#7777: Integrate PFS memory instrumentation with InnoDB
Account all memory allocations in InnoDB via PFS using the interface provided by "WL#3249 PERFORMANCE SCHEMA, Instrument memory usage". Introduce a new mechanism for allocating memory in InnoDB and replace all current calls to "new" and "ut_malloc()" with it. It will do the tracing via the PFS mechanisms.
From user perspective no changes, except more entries will appear in performance_schema tables: | memory_summary_by_account_by_event_name | | memory_summary_by_host_by_event_name | | memory_summary_by_thread_by_event_name | | memory_summary_by_user_by_event_name | | memory_summary_global_by_event_name |
Translation table from old code to the new mechanism: 1. Foo* f = new Foo(args); or Foo* f = new(std::nothrow) Foo(args); is replaced with: Foo* f = UT_NEW_NOKEY(Foo(args)); (will default to event_name like memory/innodb/dict0stats based on the file name) or Foo* f = UT_NEW(Foo(args), mem_key_dict_stats_index_map_t); (will use a custom event_name defined in ut0new.h for the key) 2. Foo* f = new Foo; or Foo* f = new(std::nothrow) Foo; is replaced with: Foo* f = UT_NEW_ARRAY_NOKEY(Foo, 16); or Foo* f = UT_NEW_ARRAY(Foo, 16, key); ut_allocator must be supplied to std::* containers as a custom allocator. 3. For example: std::vector
is replaced with: std::vector > and objects of this type are created like: std::vector > v; (will default to event_name memory/innodb/std) or std::vector > v(ut_allocator (key)); (will use a custom event_name defined in ut0new.h for the key) Since the PFS code requires the caller to provide (key, size) to the memory-free accounting method (not only to the one that accounts the allocation) this data must be stored somewhere. It can be stored either in a global variable or at the start of each allocated memory. The global variable is cleaner but requires an access regulation by a rwlock or mutex. The start of each allocated memory does not require that but is hackish. This WL will use the second approach.
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