8025277: Add -XX: flag to print code cache sweeper statistics
Summary: New diagnostic flag prints statistics about the code cache sweeper
Reviewed-by: kvn
Contributed-by: tobi.hartmann@gmail.com
--- a/hotspot/src/share/vm/runtime/globals.hpp Thu Dec 19 06:09:16 2013 +0100
+++ b/hotspot/src/share/vm/runtime/globals.hpp Thu Dec 19 14:08:02 2013 +0100
@@ -2531,6 +2531,9 @@
develop(bool, PrintMethodFlushing, false, \
"Print the nmethods being flushed") \
\
+ diagnostic(bool, PrintMethodFlushingStatistics, false, \
+ "print statistics about method flushing") \
+ \
develop(bool, UseRelocIndex, false, \
"Use an index to speed random access to relocations") \
\
--- a/hotspot/src/share/vm/runtime/java.cpp Thu Dec 19 06:09:16 2013 +0100
+++ b/hotspot/src/share/vm/runtime/java.cpp Thu Dec 19 14:08:02 2013 +0100
@@ -52,6 +52,7 @@
#include "runtime/memprofiler.hpp"
#include "runtime/sharedRuntime.hpp"
#include "runtime/statSampler.hpp"
+#include "runtime/sweeper.hpp"
#include "runtime/task.hpp"
#include "runtime/thread.inline.hpp"
#include "runtime/timer.hpp"
@@ -217,9 +218,7 @@
// General statistics printing (profiling ...)
-
void print_statistics() {
-
#ifdef ASSERT
if (CountRuntimeCalls) {
@@ -315,6 +314,10 @@
CodeCache::print();
}
+ if (PrintMethodFlushingStatistics) {
+ NMethodSweeper::print();
+ }
+
if (PrintCodeCache2) {
MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
CodeCache::print_internals();
@@ -382,6 +385,10 @@
CodeCache::print();
}
+ if (PrintMethodFlushingStatistics) {
+ NMethodSweeper::print();
+ }
+
#ifdef COMPILER2
if (PrintPreciseBiasedLockingStatistics) {
OptoRuntime::print_named_counters();
--- a/hotspot/src/share/vm/runtime/sweeper.cpp Thu Dec 19 06:09:16 2013 +0100
+++ b/hotspot/src/share/vm/runtime/sweeper.cpp Thu Dec 19 14:08:02 2013 +0100
@@ -129,6 +129,7 @@
nmethod* NMethodSweeper::_current = NULL; // Current nmethod
long NMethodSweeper::_traversals = 0; // Stack scan count, also sweep ID.
+long NMethodSweeper::_total_nof_code_cache_sweeps = 0; // Total number of full sweeps of the code cache
long NMethodSweeper::_time_counter = 0; // Virtual time used to periodically invoke sweeper
long NMethodSweeper::_last_sweep = 0; // Value of _time_counter when the last sweep happened
int NMethodSweeper::_seen = 0; // Nof. nmethod we have currently processed in current pass of CodeCache
@@ -143,13 +144,16 @@
// 1) alive -> not_entrant
// 2) not_entrant -> zombie
// 3) zombie -> marked_for_reclamation
+int NMethodSweeper::_hotness_counter_reset_val = 0;
-int NMethodSweeper::_total_nof_methods_reclaimed = 0; // Accumulated nof methods flushed
-Tickspan NMethodSweeper::_total_time_sweeping; // Accumulated time sweeping
-Tickspan NMethodSweeper::_total_time_this_sweep; // Total time this sweep
-Tickspan NMethodSweeper::_peak_sweep_time; // Peak time for a full sweep
-Tickspan NMethodSweeper::_peak_sweep_fraction_time; // Peak time sweeping one fraction
-int NMethodSweeper::_hotness_counter_reset_val = 0;
+long NMethodSweeper::_total_nof_methods_reclaimed = 0; // Accumulated nof methods flushed
+long NMethodSweeper::_total_nof_c2_methods_reclaimed = 0; // Accumulated nof methods flushed
+size_t NMethodSweeper::_total_flushed_size = 0; // Total number of bytes flushed from the code cache
+Tickspan NMethodSweeper::_total_time_sweeping; // Accumulated time sweeping
+Tickspan NMethodSweeper::_total_time_this_sweep; // Total time this sweep
+Tickspan NMethodSweeper::_peak_sweep_time; // Peak time for a full sweep
+Tickspan NMethodSweeper::_peak_sweep_fraction_time; // Peak time sweeping one fraction
+
class MarkActivationClosure: public CodeBlobClosure {
@@ -292,6 +296,7 @@
// We are done with sweeping the code cache once.
if (_sweep_fractions_left == 0) {
+ _total_nof_code_cache_sweeps++;
_last_sweep = _time_counter;
// Reset flag; temporarily disables sweeper
_should_sweep = false;
@@ -378,6 +383,7 @@
_total_time_sweeping += sweep_time;
_total_time_this_sweep += sweep_time;
_peak_sweep_fraction_time = MAX2(sweep_time, _peak_sweep_fraction_time);
+ _total_flushed_size += freed_memory;
_total_nof_methods_reclaimed += _flushed_count;
EventSweepCodeCache event(UNTIMED);
@@ -509,6 +515,9 @@
tty->print_cr("### Nmethod %3d/" PTR_FORMAT " (marked for reclamation) being flushed", nm->compile_id(), nm);
}
freed_memory = nm->total_size();
+ if (nm->is_compiled_by_c2()) {
+ _total_nof_c2_methods_reclaimed++;
+ }
release_nmethod(nm);
_flushed_count++;
} else {
@@ -547,6 +556,9 @@
SWEEP(nm);
// No inline caches will ever point to osr methods, so we can just remove it
freed_memory = nm->total_size();
+ if (nm->is_compiled_by_c2()) {
+ _total_nof_c2_methods_reclaimed++;
+ }
release_nmethod(nm);
_flushed_count++;
} else {
@@ -634,3 +646,13 @@
xtty->end_elem();
}
}
+
+void NMethodSweeper::print() {
+ ttyLocker ttyl;
+ tty->print_cr("Code cache sweeper statistics:");
+ tty->print_cr(" Total sweep time: %1.0lfms", (double)_total_time_sweeping.value()/1000000);
+ tty->print_cr(" Total number of full sweeps: %ld", _total_nof_code_cache_sweeps);
+ tty->print_cr(" Total number of flushed methods: %ld(%ld C2 methods)", _total_nof_methods_reclaimed,
+ _total_nof_c2_methods_reclaimed);
+ tty->print_cr(" Total size of flushed methods: " SIZE_FORMAT "kB", _total_flushed_size/K);
+}
--- a/hotspot/src/share/vm/runtime/sweeper.hpp Thu Dec 19 06:09:16 2013 +0100
+++ b/hotspot/src/share/vm/runtime/sweeper.hpp Thu Dec 19 14:08:02 2013 +0100
@@ -54,28 +54,33 @@
// is full.
class NMethodSweeper : public AllStatic {
- static long _traversals; // Stack scan count, also sweep ID.
- static long _time_counter; // Virtual time used to periodically invoke sweeper
- static long _last_sweep; // Value of _time_counter when the last sweep happened
- static nmethod* _current; // Current nmethod
- static int _seen; // Nof. nmethod we have currently processed in current pass of CodeCache
- static int _flushed_count; // Nof. nmethods flushed in current sweep
- static int _zombified_count; // Nof. nmethods made zombie in current sweep
- static int _marked_for_reclamation_count; // Nof. nmethods marked for reclaim in current sweep
+ static long _traversals; // Stack scan count, also sweep ID.
+ static long _total_nof_code_cache_sweeps; // Total number of full sweeps of the code cache
+ static long _time_counter; // Virtual time used to periodically invoke sweeper
+ static long _last_sweep; // Value of _time_counter when the last sweep happened
+ static nmethod* _current; // Current nmethod
+ static int _seen; // Nof. nmethod we have currently processed in current pass of CodeCache
+ static int _flushed_count; // Nof. nmethods flushed in current sweep
+ static int _zombified_count; // Nof. nmethods made zombie in current sweep
+ static int _marked_for_reclamation_count; // Nof. nmethods marked for reclaim in current sweep
- static volatile int _sweep_fractions_left; // Nof. invocations left until we are completed with this pass
- static volatile int _sweep_started; // Flag to control conc sweeper
- static volatile bool _should_sweep; // Indicates if we should invoke the sweeper
- static volatile int _bytes_changed; // Counts the total nmethod size if the nmethod changed from:
- // 1) alive -> not_entrant
- // 2) not_entrant -> zombie
- // 3) zombie -> marked_for_reclamation
+ static volatile int _sweep_fractions_left; // Nof. invocations left until we are completed with this pass
+ static volatile int _sweep_started; // Flag to control conc sweeper
+ static volatile bool _should_sweep; // Indicates if we should invoke the sweeper
+ static volatile int _bytes_changed; // Counts the total nmethod size if the nmethod changed from:
+ // 1) alive -> not_entrant
+ // 2) not_entrant -> zombie
+ // 3) zombie -> marked_for_reclamation
// Stat counters
- static int _total_nof_methods_reclaimed; // Accumulated nof methods flushed
- static Tickspan _total_time_sweeping; // Accumulated time sweeping
- static Tickspan _total_time_this_sweep; // Total time this sweep
- static Tickspan _peak_sweep_time; // Peak time for a full sweep
- static Tickspan _peak_sweep_fraction_time; // Peak time sweeping one fraction
+ static long _total_nof_methods_reclaimed; // Accumulated nof methods flushed
+ static long _total_nof_c2_methods_reclaimed; // Accumulated nof C2-compiled methods flushed
+ static size_t _total_flushed_size; // Total size of flushed methods
+ static int _hotness_counter_reset_val;
+
+ static Tickspan _total_time_sweeping; // Accumulated time sweeping
+ static Tickspan _total_time_this_sweep; // Total time this sweep
+ static Tickspan _peak_sweep_time; // Peak time for a full sweep
+ static Tickspan _peak_sweep_fraction_time; // Peak time sweeping one fraction
static int process_nmethod(nmethod *nm);
static void release_nmethod(nmethod* nm);
@@ -83,8 +88,6 @@
static bool sweep_in_progress();
static void sweep_code_cache();
- static int _hotness_counter_reset_val;
-
public:
static long traversal_count() { return _traversals; }
static int total_nof_methods_reclaimed() { return _total_nof_methods_reclaimed; }
@@ -105,10 +108,10 @@
static void mark_active_nmethods(); // Invoked at the end of each safepoint
static void possibly_sweep(); // Compiler threads call this to sweep
- static int sort_nmethods_by_hotness(nmethod** nm1, nmethod** nm2);
static int hotness_counter_reset_val();
static void report_state_change(nmethod* nm);
static void possibly_enable_sweeper();
+ static void print(); // Printing/debugging
};
#endif // SHARE_VM_RUNTIME_SWEEPER_HPP