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src/hotspot/share/memory/metaspace.hpp
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rev 49873 : [mq]: 8201572-improve-metaspace-reporting
@@ -66,10 +66,15 @@
class PrintCLDMetaspaceInfoClosure;
class SpaceManager;
class VirtualSpaceList;
class CollectedHeap;
+namespace metaspace {
+namespace internals {
+ class ClassLoaderMetaspaceStatistics;
+}}
+
// Metaspaces each have a SpaceManager and allocations
// are done by the SpaceManager. Allocations are done
// out of the current Metachunk. When the current Metachunk
// is exhausted, the SpaceManager gets a new one from
// the current VirtualSpace. When the VirtualSpace is exhausted
@@ -92,14 +97,18 @@
ClassType,
NonClassType,
MetadataTypeCount
};
enum MetaspaceType {
- StandardMetaspaceType,
- BootMetaspaceType,
- AnonymousMetaspaceType,
- ReflectionMetaspaceType
+ ZeroMetaspaceType = 0,
+ //...
+ StandardMetaspaceType = ZeroMetaspaceType,
+ BootMetaspaceType = StandardMetaspaceType + 1,
+ AnonymousMetaspaceType = BootMetaspaceType + 1,
+ ReflectionMetaspaceType = AnonymousMetaspaceType + 1,
+ //..
+ MetaspaceTypeCount
};
private:
// Align up the word size to the allocation word size
@@ -191,11 +200,10 @@
static size_t commit_alignment() { return _commit_alignment; }
static size_t commit_alignment_words() { return _commit_alignment / BytesPerWord; }
static MetaWord* allocate(ClassLoaderData* loader_data, size_t word_size,
MetaspaceObj::Type type, TRAPS);
- void deallocate(MetaWord* ptr, size_t byte_size, bool is_class);
static bool contains(const void* ptr);
static bool contains_non_shared(const void* ptr);
// Free empty virtualspaces
@@ -236,100 +244,101 @@
// special cases such as the boot class loader, reflection
// class loader and anonymous class loader.
void initialize_first_chunk(Metaspace::MetaspaceType type, Metaspace::MetadataType mdtype);
Metachunk* get_initialization_chunk(Metaspace::MetaspaceType type, Metaspace::MetadataType mdtype);
+ const Metaspace::MetaspaceType _space_type;
+ Mutex* const _lock;
SpaceManager* _vsm;
- SpaceManager* vsm() const { return _vsm; }
-
SpaceManager* _class_vsm;
+
+ SpaceManager* vsm() const { return _vsm; }
SpaceManager* class_vsm() const { return _class_vsm; }
SpaceManager* get_space_manager(Metaspace::MetadataType mdtype) {
assert(mdtype != Metaspace::MetadataTypeCount, "MetadaTypeCount can't be used as mdtype");
return mdtype == Metaspace::ClassType ? class_vsm() : vsm();
}
+ Mutex* lock() const { return _lock; }
+
MetaWord* expand_and_allocate(size_t size, Metaspace::MetadataType mdtype);
size_t class_chunk_size(size_t word_size);
+ // Adds to the given statistic object. Must be locked with CLD metaspace lock.
+ void add_to_statistics_locked(metaspace::internals::ClassLoaderMetaspaceStatistics* out) const;
+
public:
ClassLoaderMetaspace(Mutex* lock, Metaspace::MetaspaceType type);
~ClassLoaderMetaspace();
+ Metaspace::MetaspaceType space_type() const { return _space_type; }
+
// Allocate space for metadata of type mdtype. This is space
// within a Metachunk and is used by
// allocate(ClassLoaderData*, size_t, bool, MetadataType, TRAPS)
MetaWord* allocate(size_t word_size, Metaspace::MetadataType mdtype);
- size_t used_words_slow(Metaspace::MetadataType mdtype) const;
- size_t free_words_slow(Metaspace::MetadataType mdtype) const;
- size_t capacity_words_slow(Metaspace::MetadataType mdtype) const;
-
- size_t used_bytes_slow(Metaspace::MetadataType mdtype) const;
- size_t capacity_bytes_slow(Metaspace::MetadataType mdtype) const;
-
size_t allocated_blocks_bytes() const;
size_t allocated_chunks_bytes() const;
void deallocate(MetaWord* ptr, size_t byte_size, bool is_class);
- void dump(outputStream* const out) const;
-
void print_on(outputStream* st) const;
// Debugging support
void verify();
-}; // ClassLoaderMetaspace
+ // Adds to the given statistic object. Will lock with CLD metaspace lock.
+ void add_to_statistics(metaspace::internals::ClassLoaderMetaspaceStatistics* out) const;
+}; // ClassLoaderMetaspace
class MetaspaceUtils : AllStatic {
+
+ // Spacemanager updates running counters.
+ friend class SpaceManager;
+
+ // Running counters for statistics concerning in-use chunks.
+ // Note: capacity = used + free + waste + overhead. Note that we do not
+ // count free and waste. Their sum can be deduces from the three other values.
+ // For more details, one should call print_report() from within a safe point.
+ static size_t _capacity_words [Metaspace:: MetadataTypeCount];
+ static size_t _overhead_words [Metaspace:: MetadataTypeCount];
+ static volatile size_t _used_words [Metaspace:: MetadataTypeCount];
+
+ // Atomically decrement or increment in-use statistic counters
+ static void dec_capacity(Metaspace::MetadataType mdtype, size_t words);
+ static void inc_capacity(Metaspace::MetadataType mdtype, size_t words);
+ static void dec_used(Metaspace::MetadataType mdtype, size_t words);
+ static void inc_used(Metaspace::MetadataType mdtype, size_t words);
+ static void dec_overhead(Metaspace::MetadataType mdtype, size_t words);
+ static void inc_overhead(Metaspace::MetadataType mdtype, size_t words);
+
+
+ // Getters for the in-use counters.
+ static size_t capacity_words(Metaspace::MetadataType mdtype) { return _capacity_words[mdtype]; }
+ static size_t used_words(Metaspace::MetadataType mdtype) { return _used_words[mdtype]; }
+ static size_t overhead_words(Metaspace::MetadataType mdtype) { return _overhead_words[mdtype]; }
+
static size_t free_chunks_total_words(Metaspace::MetadataType mdtype);
- // These methods iterate over the classloader data graph
- // for the given Metaspace type. These are slow.
- static size_t used_bytes_slow(Metaspace::MetadataType mdtype);
- static size_t free_bytes_slow(Metaspace::MetadataType mdtype);
- static size_t capacity_bytes_slow(Metaspace::MetadataType mdtype);
- static size_t capacity_bytes_slow();
-
- // Running sum of space in all Metachunks that has been
- // allocated to a Metaspace. This is used instead of
- // iterating over all the classloaders. One for each
- // type of Metadata
- static size_t _capacity_words[Metaspace:: MetadataTypeCount];
- // Running sum of space in all Metachunks that
- // are being used for metadata. One for each
- // type of Metadata.
- static volatile size_t _used_words[Metaspace:: MetadataTypeCount];
+ // Helper for print_xx_report.
+ static void print_vs(outputStream* out, size_t scale);
- public:
- // Decrement and increment _allocated_capacity_words
- static void dec_capacity(Metaspace::MetadataType type, size_t words);
- static void inc_capacity(Metaspace::MetadataType type, size_t words);
-
- // Decrement and increment _allocated_used_words
- static void dec_used(Metaspace::MetadataType type, size_t words);
- static void inc_used(Metaspace::MetadataType type, size_t words);
-
- // Total of space allocated to metadata in all Metaspaces.
- // This sums the space used in each Metachunk by
- // iterating over the classloader data graph
- static size_t used_bytes_slow() {
- return used_bytes_slow(Metaspace::ClassType) +
- used_bytes_slow(Metaspace::NonClassType);
- }
+public:
+
+ // Collect used metaspace statistics. This involves walking the CLDG. The resulting
+ // output will be the accumulated values for all live metaspaces.
+ // Note: method does not do any locking.
+ static void collect_statistics(metaspace::internals::ClassLoaderMetaspaceStatistics* out);
// Used by MetaspaceCounters
static size_t free_chunks_total_words();
static size_t free_chunks_total_bytes();
static size_t free_chunks_total_bytes(Metaspace::MetadataType mdtype);
- static size_t capacity_words(Metaspace::MetadataType mdtype) {
- return _capacity_words[mdtype];
- }
static size_t capacity_words() {
return capacity_words(Metaspace::NonClassType) +
capacity_words(Metaspace::ClassType);
}
static size_t capacity_bytes(Metaspace::MetadataType mdtype) {
@@ -337,13 +346,10 @@
}
static size_t capacity_bytes() {
return capacity_words() * BytesPerWord;
}
- static size_t used_words(Metaspace::MetadataType mdtype) {
- return _used_words[mdtype];
- }
static size_t used_words() {
return used_words(Metaspace::NonClassType) +
used_words(Metaspace::ClassType);
}
static size_t used_bytes(Metaspace::MetadataType mdtype) {
@@ -351,12 +357,13 @@
}
static size_t used_bytes() {
return used_words() * BytesPerWord;
}
- static size_t free_bytes();
- static size_t free_bytes(Metaspace::MetadataType mdtype);
+ // Space committed but yet unclaimed by any class loader.
+ static size_t free_in_vs_bytes();
+ static size_t free_in_vs_bytes(Metaspace::MetadataType mdtype);
static size_t reserved_bytes(Metaspace::MetadataType mdtype);
static size_t reserved_bytes() {
return reserved_bytes(Metaspace::ClassType) +
reserved_bytes(Metaspace::NonClassType);
@@ -371,32 +378,47 @@
static size_t min_chunk_size_words();
static size_t min_chunk_size_bytes() {
return min_chunk_size_words() * BytesPerWord;
}
- static void print_metadata_for_nmt(outputStream* out, size_t scale = K);
+ // Flags for print_report().
+ enum ReportFlag {
+ // Show usage by class loader.
+ rf_show_loaders = (1 << 0),
+ // Breaks report down by chunk type (small, medium, ...).
+ rf_break_down_by_chunktype = (1 << 1),
+ // Breaks report down by space type (anonymous, reflection, ...).
+ rf_break_down_by_spacetype = (1 << 2),
+ // Print details about the underlying virtual spaces.
+ rf_show_vslist = (1 << 3),
+ // Print metaspace map.
+ rf_show_vsmap = (1 << 4),
+ };
+
+ // This will print out a basic metaspace usage report but
+ // unlike print_report() is guaranteed not to lock or to walk the CLDG.
+ static void print_basic_report(outputStream* st, size_t scale);
+
+ // Prints a report about the current metaspace state.
+ // Optional parts can be enabled via flags.
+ // Function will walk the CLDG and will lock the expand lock; if that is not
+ // convenient, use print_basic_report() instead.
+ static void print_report(outputStream* out, size_t scale = 0, int flags = 0);
static bool has_chunk_free_list(Metaspace::MetadataType mdtype);
static MetaspaceChunkFreeListSummary chunk_free_list_summary(Metaspace::MetadataType mdtype);
// Print change in used metadata.
static void print_metaspace_change(size_t prev_metadata_used);
static void print_on(outputStream * out);
- static void print_on(outputStream * out, Metaspace::MetadataType mdtype);
-
- static void print_class_waste(outputStream* out);
- static void print_waste(outputStream* out);
// Prints an ASCII representation of the given space.
static void print_metaspace_map(outputStream* out, Metaspace::MetadataType mdtype);
static void dump(outputStream* out);
static void verify_free_chunks();
- // Checks that the values returned by allocated_capacity_bytes() and
- // capacity_bytes_slow() are the same.
- static void verify_capacity();
- static void verify_used();
+ // Check internal counters (capacity, used).
static void verify_metrics();
};
// Metaspace are deallocated when their class loader are GC'ed.
// This class implements a policy for inducing GC's to recover
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