From 97f14ebfd8d24d71e10c450e0a90b6322f9c0d59 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Kamil=20Trzci=C5=84ski?= Date: Tue, 22 Dec 2020 15:33:08 +0100 Subject: [PATCH] Expose `Thread#memory_allocations` counters This provides currently a per-thread GC heap slots and malloc allocations statistics. This is designed to measure a memory allocations in a multi-threaded environments (concurrent requests processing) with an accurate information about allocated memory within a given execution context. Example: Measure memory pressure generated by a given requests to easier find requests with a lot of allocations. Ref: https://gitlab.com/gitlab-org/gitlab/-/issues/296530 --- gc.c | 20 ++++++ .../test_thread_trace_memory_allocations.rb | 67 +++++++++++++++++++ thread.c | 55 +++++++++++++++ vm_core.h | 17 +++++ 4 files changed, 159 insertions(+) create mode 100644 test/ruby/test_thread_trace_memory_allocations.rb diff --git a/gc.c b/gc.c index 5d0c342..b82d35f 100644 --- a/gc.c +++ b/gc.c @@ -2126,6 +2126,13 @@ newobj_init(VALUE klass, VALUE flags, int wb_protected, rb_objspace_t *objspace, // TODO: make it atomic, or ractor local objspace->total_allocated_objects++; +#if THREAD_TRACE_MEMORY_ALLOCATIONS + rb_thread_t *th = ruby_threadptr_for_trace_memory_allocations(); + if (th) { + ATOMIC_SIZE_INC(th->memory_allocations.total_allocated_objects); + } +#endif + #if RGENGC_PROFILE if (wb_protected) { objspace->profile.total_generated_normal_object_count++; @@ -10446,6 +10453,19 @@ objspace_malloc_increase(rb_objspace_t *objspace, void *mem, size_t new_size, si #endif } +#if THREAD_TRACE_MEMORY_ALLOCATIONS + rb_thread_t *th = ruby_threadptr_for_trace_memory_allocations(); + if (th) { + if (new_size > old_size) { + ATOMIC_SIZE_ADD(th->memory_allocations.total_malloc_bytes, new_size - old_size); + } + + if (type == MEMOP_TYPE_MALLOC) { + ATOMIC_SIZE_INC(th->memory_allocations.total_mallocs); + } + } +#endif + if (type == MEMOP_TYPE_MALLOC) { retry: if (malloc_increase > malloc_limit && ruby_native_thread_p() && !dont_gc_val()) { diff --git a/test/ruby/test_thread_trace_memory_allocations.rb b/test/ruby/test_thread_trace_memory_allocations.rb new file mode 100644 index 0000000..2e28151 --- /dev/null +++ b/test/ruby/test_thread_trace_memory_allocations.rb @@ -0,0 +1,67 @@ +# frozen_string_literal: true + +require 'test/unit' + +class TestThreadTraceMemoryAllocations < Test::Unit::TestCase + def test_disabled_trace_memory_allocations + Thread.trace_memory_allocations = false + + assert_predicate Thread.current.memory_allocations, :nil? + end + + def test_enabled_trace_memory_allocations + Thread.trace_memory_allocations = true + + assert_not_nil(Thread.current.memory_allocations) + end + + def test_only_this_thread_allocations_are_counted + changed = { + total_allocated_objects: 1000, + total_malloc_bytes: 1_000_000, + total_mallocs: 100 + } + + Thread.trace_memory_allocations = true + + assert_less_than(changed) do + Thread.new do + assert_greater_than(changed) do + # This will allocate: 5k objects, 5k mallocs, 5MB + allocate(5000, 1000) + end + end.join + + # This will allocate: 50 objects, 50 mallocs, 500 bytes + allocate(50, 10) + end + end + + private + + def allocate(slots, bytes) + Array.new(slots).map do + '0' * bytes + end + end + + def assert_greater_than(keys) + before = Thread.current.memory_allocations + yield + after = Thread.current.memory_allocations + + keys.each do |key, by| + assert_operator(by, :<=, after[key]-before[key], "expected the #{key} to change more than #{by}") + end + end + + def assert_less_than(keys) + before = Thread.current.memory_allocations + yield + after = Thread.current.memory_allocations + + keys.each do |key, by| + assert_operator(by, :>, after[key]-before[key], "expected the #{key} to change less than #{by}") + end + end +end diff --git a/thread.c b/thread.c index 59279ef..be6014f 100644 --- a/thread.c +++ b/thread.c @@ -5438,6 +5438,55 @@ Init_Thread_Mutex(void) rb_native_mutex_initialize(&th->interrupt_lock); } +#if THREAD_TRACE_MEMORY_ALLOCATIONS +rb_thread_t * +ruby_threadptr_for_trace_memory_allocations(void) +{ + // The order of this checks is important due + // to how Ruby VM is initialized + if (GET_VM()->thread_trace_memory_allocations && GET_EC() != NULL) { + return GET_THREAD(); + } + + return NULL; +} + +static VALUE +rb_thread_s_trace_memory_allocations(VALUE _) +{ + return GET_THREAD()->vm->thread_trace_memory_allocations ? Qtrue : Qfalse; +} + +static VALUE +rb_thread_s_trace_memory_allocations_set(VALUE self, VALUE val) +{ + GET_THREAD()->vm->thread_trace_memory_allocations = RTEST(val); + return val; +} + +static VALUE +rb_thread_memory_allocations(VALUE self) +{ + rb_thread_t *th = rb_thread_ptr(self); + + if (!th->vm->thread_trace_memory_allocations) { + return Qnil; + } + + VALUE ret = rb_hash_new(); + + VALUE total_allocated_objects = ID2SYM(rb_intern_const("total_allocated_objects")); + VALUE total_malloc_bytes = ID2SYM(rb_intern_const("total_malloc_bytes")); + VALUE total_mallocs = ID2SYM(rb_intern_const("total_mallocs")); + + rb_hash_aset(ret, total_allocated_objects, SIZET2NUM(th->memory_allocations.total_allocated_objects)); + rb_hash_aset(ret, total_malloc_bytes, SIZET2NUM(th->memory_allocations.total_malloc_bytes)); + rb_hash_aset(ret, total_mallocs, SIZET2NUM(th->memory_allocations.total_mallocs)); + + return ret; +} +#endif + /* * Document-class: ThreadError * @@ -5523,6 +5572,12 @@ Init_Thread(void) rb_define_method(rb_cThread, "to_s", rb_thread_to_s, 0); rb_define_alias(rb_cThread, "inspect", "to_s"); +#if THREAD_TRACE_MEMORY_ALLOCATIONS + rb_define_singleton_method(rb_cThread, "trace_memory_allocations", rb_thread_s_trace_memory_allocations, 0); + rb_define_singleton_method(rb_cThread, "trace_memory_allocations=", rb_thread_s_trace_memory_allocations_set, 1); + rb_define_method(rb_cThread, "memory_allocations", rb_thread_memory_allocations, 0); +#endif + rb_vm_register_special_exception(ruby_error_stream_closed, rb_eIOError, "stream closed in another thread"); diff --git a/vm_core.h b/vm_core.h index 6ab3608..196ab92 100644 --- a/vm_core.h +++ b/vm_core.h @@ -97,6 +97,13 @@ # define VM_INSN_INFO_TABLE_IMPL 2 #endif +/* + * track a per thread memory allocations + */ +#ifndef THREAD_TRACE_MEMORY_ALLOCATIONS +# define THREAD_TRACE_MEMORY_ALLOCATIONS 1 +#endif + #if defined(NSIG_MAX) /* POSIX issue 8 */ # undef NSIG # define NSIG NSIG_MAX @@ -606,6 +613,7 @@ typedef struct rb_vm_struct { unsigned int thread_abort_on_exception: 1; unsigned int thread_report_on_exception: 1; unsigned int thread_ignore_deadlock: 1; + unsigned int thread_trace_memory_allocations: 1; /* object management */ VALUE mark_object_ary; @@ -986,6 +994,14 @@ typedef struct rb_thread_struct { struct rb_waiting_list *join_list; +#if THREAD_TRACE_MEMORY_ALLOCATIONS + struct { + size_t total_allocated_objects; + size_t total_malloc_bytes; + size_t total_mallocs; + } memory_allocations; +#endif + union { struct { VALUE proc; @@ -1906,6 +1922,7 @@ void rb_threadptr_interrupt(rb_thread_t *th); void rb_threadptr_unlock_all_locking_mutexes(rb_thread_t *th); void rb_threadptr_pending_interrupt_clear(rb_thread_t *th); void rb_threadptr_pending_interrupt_enque(rb_thread_t *th, VALUE v); +rb_thread_t *ruby_threadptr_for_trace_memory_allocations(void); VALUE rb_ec_get_errinfo(const rb_execution_context_t *ec); void rb_ec_error_print(rb_execution_context_t * volatile ec, volatile VALUE errinfo); void rb_execution_context_update(const rb_execution_context_t *ec);