8015391: NPG: With -XX:+UseCompressedKlassPointers OOME due to exhausted metadata space could occur when metaspace is almost empty
Summary: Allocate medium chunks for class metaspace when class loader has lots of classes
Reviewed-by: mgerdin, jmasa
--- a/hotspot/src/share/vm/memory/metaspace.cpp Thu Jun 20 11:53:51 2013 +0200
+++ b/hotspot/src/share/vm/memory/metaspace.cpp Tue Jul 02 08:42:37 2013 -0400
@@ -70,7 +70,7 @@
SpecializedChunk = 128,
ClassSmallChunk = 256,
SmallChunk = 512,
- ClassMediumChunk = 1 * K,
+ ClassMediumChunk = 4 * K,
MediumChunk = 8 * K,
HumongousChunkGranularity = 8
};
@@ -580,7 +580,6 @@
// Number of small chunks to allocate to a manager
// If class space manager, small chunks are unlimited
static uint const _small_chunk_limit;
- bool has_small_chunk_limit() { return !vs_list()->is_class(); }
// Sum of all space in allocated chunks
size_t _allocated_blocks_words;
@@ -1298,13 +1297,18 @@
bool MetaspaceGC::should_expand(VirtualSpaceList* vsl, size_t word_size) {
- size_t committed_capacity_bytes = MetaspaceAux::allocated_capacity_bytes();
// If the user wants a limit, impose one.
- size_t max_metaspace_size_bytes = MaxMetaspaceSize;
- size_t metaspace_size_bytes = MetaspaceSize;
- if (!FLAG_IS_DEFAULT(MaxMetaspaceSize) &&
- MetaspaceAux::reserved_in_bytes() >= MaxMetaspaceSize) {
- return false;
+ // The reason for someone using this flag is to limit reserved space. So
+ // for non-class virtual space, compare against virtual spaces that are reserved.
+ // For class virtual space, we only compare against the committed space, not
+ // reserved space, because this is a larger space prereserved for compressed
+ // class pointers.
+ if (!FLAG_IS_DEFAULT(MaxMetaspaceSize)) {
+ size_t real_allocated = Metaspace::space_list()->virtual_space_total() +
+ MetaspaceAux::allocated_capacity_bytes(Metaspace::ClassType);
+ if (real_allocated >= MaxMetaspaceSize) {
+ return false;
+ }
}
// Class virtual space should always be expanded. Call GC for the other
@@ -1318,11 +1322,12 @@
}
-
// If the capacity is below the minimum capacity, allow the
// expansion. Also set the high-water-mark (capacity_until_GC)
// to that minimum capacity so that a GC will not be induced
// until that minimum capacity is exceeded.
+ size_t committed_capacity_bytes = MetaspaceAux::allocated_capacity_bytes();
+ size_t metaspace_size_bytes = MetaspaceSize;
if (committed_capacity_bytes < metaspace_size_bytes ||
capacity_until_GC() == 0) {
set_capacity_until_GC(metaspace_size_bytes);
@@ -1866,13 +1871,11 @@
Metachunk* chunk = chunks_in_use(index);
// Count the free space in all the chunk but not the
// current chunk from which allocations are still being done.
- if (chunk != NULL) {
- Metachunk* prev = chunk;
- while (chunk != NULL && chunk != current_chunk()) {
+ while (chunk != NULL) {
+ if (chunk != current_chunk()) {
result += chunk->free_word_size();
- prev = chunk;
- chunk = chunk->next();
}
+ chunk = chunk->next();
}
return result;
}
@@ -1961,8 +1964,7 @@
// chunks will be allocated.
size_t chunk_word_size;
if (chunks_in_use(MediumIndex) == NULL &&
- (!has_small_chunk_limit() ||
- sum_count_in_chunks_in_use(SmallIndex) < _small_chunk_limit)) {
+ sum_count_in_chunks_in_use(SmallIndex) < _small_chunk_limit) {
chunk_word_size = (size_t) small_chunk_size();
if (word_size + Metachunk::overhead() > small_chunk_size()) {
chunk_word_size = medium_chunk_size();
@@ -2671,10 +2673,10 @@
// Print total fragmentation for class and data metaspaces separately
void MetaspaceAux::print_waste(outputStream* out) {
- size_t specialized_waste = 0, small_waste = 0, medium_waste = 0, large_waste = 0;
- size_t specialized_count = 0, small_count = 0, medium_count = 0, large_count = 0;
- size_t cls_specialized_waste = 0, cls_small_waste = 0, cls_medium_waste = 0, cls_large_waste = 0;
- size_t cls_specialized_count = 0, cls_small_count = 0, cls_medium_count = 0, cls_large_count = 0;
+ size_t specialized_waste = 0, small_waste = 0, medium_waste = 0;
+ size_t specialized_count = 0, small_count = 0, medium_count = 0, humongous_count = 0;
+ size_t cls_specialized_waste = 0, cls_small_waste = 0, cls_medium_waste = 0;
+ size_t cls_specialized_count = 0, cls_small_count = 0, cls_medium_count = 0, cls_humongous_count = 0;
ClassLoaderDataGraphMetaspaceIterator iter;
while (iter.repeat()) {
@@ -2686,8 +2688,7 @@
small_count += msp->vsm()->sum_count_in_chunks_in_use(SmallIndex);
medium_waste += msp->vsm()->sum_waste_in_chunks_in_use(MediumIndex);
medium_count += msp->vsm()->sum_count_in_chunks_in_use(MediumIndex);
- large_waste += msp->vsm()->sum_waste_in_chunks_in_use(HumongousIndex);
- large_count += msp->vsm()->sum_count_in_chunks_in_use(HumongousIndex);
+ humongous_count += msp->vsm()->sum_count_in_chunks_in_use(HumongousIndex);
cls_specialized_waste += msp->class_vsm()->sum_waste_in_chunks_in_use(SpecializedIndex);
cls_specialized_count += msp->class_vsm()->sum_count_in_chunks_in_use(SpecializedIndex);
@@ -2695,20 +2696,23 @@
cls_small_count += msp->class_vsm()->sum_count_in_chunks_in_use(SmallIndex);
cls_medium_waste += msp->class_vsm()->sum_waste_in_chunks_in_use(MediumIndex);
cls_medium_count += msp->class_vsm()->sum_count_in_chunks_in_use(MediumIndex);
- cls_large_waste += msp->class_vsm()->sum_waste_in_chunks_in_use(HumongousIndex);
- cls_large_count += msp->class_vsm()->sum_count_in_chunks_in_use(HumongousIndex);
+ cls_humongous_count += msp->class_vsm()->sum_count_in_chunks_in_use(HumongousIndex);
}
}
out->print_cr("Total fragmentation waste (words) doesn't count free space");
out->print_cr(" data: " SIZE_FORMAT " specialized(s) " SIZE_FORMAT ", "
SIZE_FORMAT " small(s) " SIZE_FORMAT ", "
- SIZE_FORMAT " medium(s) " SIZE_FORMAT,
+ SIZE_FORMAT " medium(s) " SIZE_FORMAT ", "
+ "large count " SIZE_FORMAT,
specialized_count, specialized_waste, small_count,
- small_waste, medium_count, medium_waste);
+ small_waste, medium_count, medium_waste, humongous_count);
out->print_cr(" class: " SIZE_FORMAT " specialized(s) " SIZE_FORMAT ", "
- SIZE_FORMAT " small(s) " SIZE_FORMAT,
+ SIZE_FORMAT " small(s) " SIZE_FORMAT ", "
+ SIZE_FORMAT " medium(s) " SIZE_FORMAT ", "
+ "large count " SIZE_FORMAT,
cls_specialized_count, cls_specialized_waste,
- cls_small_count, cls_small_waste);
+ cls_small_count, cls_small_waste,
+ cls_medium_count, cls_medium_waste, cls_humongous_count);
}
// Dump global metaspace things from the end of ClassLoaderDataGraph
@@ -3049,18 +3053,24 @@
if (Verbose && TraceMetadataChunkAllocation) {
gclog_or_tty->print_cr("Metaspace allocation failed for size "
SIZE_FORMAT, word_size);
- if (loader_data->metaspace_or_null() != NULL) loader_data->metaspace_or_null()->dump(gclog_or_tty);
+ if (loader_data->metaspace_or_null() != NULL) loader_data->dump(gclog_or_tty);
MetaspaceAux::dump(gclog_or_tty);
}
// -XX:+HeapDumpOnOutOfMemoryError and -XX:OnOutOfMemoryError support
- report_java_out_of_memory("Metadata space");
+ const char* space_string = (mdtype == ClassType) ? "Class Metadata space" :
+ "Metadata space";
+ report_java_out_of_memory(space_string);
if (JvmtiExport::should_post_resource_exhausted()) {
JvmtiExport::post_resource_exhausted(
JVMTI_RESOURCE_EXHAUSTED_OOM_ERROR,
- "Metadata space");
+ space_string);
}
- THROW_OOP_0(Universe::out_of_memory_error_perm_gen());
+ if (mdtype == ClassType) {
+ THROW_OOP_0(Universe::out_of_memory_error_class_metaspace());
+ } else {
+ THROW_OOP_0(Universe::out_of_memory_error_metaspace());
+ }
}
}
return Metablock::initialize(result, word_size);
--- a/hotspot/src/share/vm/memory/universe.cpp Thu Jun 20 11:53:51 2013 +0200
+++ b/hotspot/src/share/vm/memory/universe.cpp Tue Jul 02 08:42:37 2013 -0400
@@ -110,7 +110,8 @@
LatestMethodOopCache* Universe::_loader_addClass_cache = NULL;
ActiveMethodOopsCache* Universe::_reflect_invoke_cache = NULL;
oop Universe::_out_of_memory_error_java_heap = NULL;
-oop Universe::_out_of_memory_error_perm_gen = NULL;
+oop Universe::_out_of_memory_error_metaspace = NULL;
+oop Universe::_out_of_memory_error_class_metaspace = NULL;
oop Universe::_out_of_memory_error_array_size = NULL;
oop Universe::_out_of_memory_error_gc_overhead_limit = NULL;
objArrayOop Universe::_preallocated_out_of_memory_error_array = NULL;
@@ -179,7 +180,8 @@
f->do_oop((oop*)&_the_null_string);
f->do_oop((oop*)&_the_min_jint_string);
f->do_oop((oop*)&_out_of_memory_error_java_heap);
- f->do_oop((oop*)&_out_of_memory_error_perm_gen);
+ f->do_oop((oop*)&_out_of_memory_error_metaspace);
+ f->do_oop((oop*)&_out_of_memory_error_class_metaspace);
f->do_oop((oop*)&_out_of_memory_error_array_size);
f->do_oop((oop*)&_out_of_memory_error_gc_overhead_limit);
f->do_oop((oop*)&_preallocated_out_of_memory_error_array);
@@ -561,7 +563,8 @@
// a potential loop which could happen if an out of memory occurs when attempting
// to allocate the backtrace.
return ((throwable() != Universe::_out_of_memory_error_java_heap) &&
- (throwable() != Universe::_out_of_memory_error_perm_gen) &&
+ (throwable() != Universe::_out_of_memory_error_metaspace) &&
+ (throwable() != Universe::_out_of_memory_error_class_metaspace) &&
(throwable() != Universe::_out_of_memory_error_array_size) &&
(throwable() != Universe::_out_of_memory_error_gc_overhead_limit));
}
@@ -1011,7 +1014,8 @@
k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_OutOfMemoryError(), true, CHECK_false);
k_h = instanceKlassHandle(THREAD, k);
Universe::_out_of_memory_error_java_heap = k_h->allocate_instance(CHECK_false);
- Universe::_out_of_memory_error_perm_gen = k_h->allocate_instance(CHECK_false);
+ Universe::_out_of_memory_error_metaspace = k_h->allocate_instance(CHECK_false);
+ Universe::_out_of_memory_error_class_metaspace = k_h->allocate_instance(CHECK_false);
Universe::_out_of_memory_error_array_size = k_h->allocate_instance(CHECK_false);
Universe::_out_of_memory_error_gc_overhead_limit =
k_h->allocate_instance(CHECK_false);
@@ -1044,7 +1048,9 @@
java_lang_Throwable::set_message(Universe::_out_of_memory_error_java_heap, msg());
msg = java_lang_String::create_from_str("Metadata space", CHECK_false);
- java_lang_Throwable::set_message(Universe::_out_of_memory_error_perm_gen, msg());
+ java_lang_Throwable::set_message(Universe::_out_of_memory_error_metaspace, msg());
+ msg = java_lang_String::create_from_str("Class Metadata space", CHECK_false);
+ java_lang_Throwable::set_message(Universe::_out_of_memory_error_class_metaspace, msg());
msg = java_lang_String::create_from_str("Requested array size exceeds VM limit", CHECK_false);
java_lang_Throwable::set_message(Universe::_out_of_memory_error_array_size, msg());
--- a/hotspot/src/share/vm/memory/universe.hpp Thu Jun 20 11:53:51 2013 +0200
+++ b/hotspot/src/share/vm/memory/universe.hpp Tue Jul 02 08:42:37 2013 -0400
@@ -177,10 +177,12 @@
static LatestMethodOopCache* _finalizer_register_cache; // static method for registering finalizable objects
static LatestMethodOopCache* _loader_addClass_cache; // method for registering loaded classes in class loader vector
static ActiveMethodOopsCache* _reflect_invoke_cache; // method for security checks
- static oop _out_of_memory_error_java_heap; // preallocated error object (no backtrace)
- static oop _out_of_memory_error_perm_gen; // preallocated error object (no backtrace)
- static oop _out_of_memory_error_array_size;// preallocated error object (no backtrace)
- static oop _out_of_memory_error_gc_overhead_limit; // preallocated error object (no backtrace)
+ // preallocated error objects (no backtrace)
+ static oop _out_of_memory_error_java_heap;
+ static oop _out_of_memory_error_metaspace;
+ static oop _out_of_memory_error_class_metaspace;
+ static oop _out_of_memory_error_array_size;
+ static oop _out_of_memory_error_gc_overhead_limit;
static Array<int>* _the_empty_int_array; // Canonicalized int array
static Array<u2>* _the_empty_short_array; // Canonicalized short array
@@ -348,7 +350,8 @@
// may or may not have a backtrace. If error has a backtrace then the stack trace is already
// filled in.
static oop out_of_memory_error_java_heap() { return gen_out_of_memory_error(_out_of_memory_error_java_heap); }
- static oop out_of_memory_error_perm_gen() { return gen_out_of_memory_error(_out_of_memory_error_perm_gen); }
+ static oop out_of_memory_error_metaspace() { return gen_out_of_memory_error(_out_of_memory_error_metaspace); }
+ static oop out_of_memory_error_class_metaspace() { return gen_out_of_memory_error(_out_of_memory_error_class_metaspace); }
static oop out_of_memory_error_array_size() { return gen_out_of_memory_error(_out_of_memory_error_array_size); }
static oop out_of_memory_error_gc_overhead_limit() { return gen_out_of_memory_error(_out_of_memory_error_gc_overhead_limit); }
--- a/hotspot/src/share/vm/runtime/vmStructs.cpp Thu Jun 20 11:53:51 2013 +0200
+++ b/hotspot/src/share/vm/runtime/vmStructs.cpp Tue Jul 02 08:42:37 2013 -0400
@@ -437,10 +437,6 @@
static_field(Universe, _main_thread_group, oop) \
static_field(Universe, _system_thread_group, oop) \
static_field(Universe, _the_empty_class_klass_array, objArrayOop) \
- static_field(Universe, _out_of_memory_error_java_heap, oop) \
- static_field(Universe, _out_of_memory_error_perm_gen, oop) \
- static_field(Universe, _out_of_memory_error_array_size, oop) \
- static_field(Universe, _out_of_memory_error_gc_overhead_limit, oop) \
static_field(Universe, _null_ptr_exception_instance, oop) \
static_field(Universe, _arithmetic_exception_instance, oop) \
static_field(Universe, _vm_exception, oop) \