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8027593: performance drop with constrained codecache starting with hs25 b111

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Fixed proper sweeping of small code cache sizes

Reviewed-by: kvn, iveresov
This commit is contained in:
Albert Noll 2013-11-12 09:32:50 +01:00
parent c632cad9d5
commit 18ca4cc301
7 changed files with 184 additions and 121 deletions
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10
hotspot/src/share/vm/code/nmethod.cpp
View File

@ -1259,7 +1259,7 @@ void nmethod::make_unloaded(BoolObjectClosure* is_alive, oop cause) {
set_osr_link(NULL);
//set_scavenge_root_link(NULL); // done by prune_scavenge_root_nmethods
NMethodSweeper::notify();
NMethodSweeper::report_state_change(this);
}
void nmethod::invalidate_osr_method() {
@ -1293,7 +1293,9 @@ void nmethod::log_state_change() const {
}
}
// Common functionality for both make_not_entrant and make_zombie
/**
* Common functionality for both make_not_entrant and make_zombie
*/
bool nmethod::make_not_entrant_or_zombie(unsigned int state) {
assert(state == zombie || state == not_entrant, "must be zombie or not_entrant");
assert(!is_zombie(), "should not already be a zombie");
@ -1417,9 +1419,7 @@ bool nmethod::make_not_entrant_or_zombie(unsigned int state) {
tty->print_cr("nmethod <" INTPTR_FORMAT "> code made %s", this, (state == not_entrant) ? "not entrant" : "zombie");
}
// Make sweeper aware that there is a zombie method that needs to be removed
NMethodSweeper::notify();
NMethodSweeper::report_state_change(this);
return true;
}

30
hotspot/src/share/vm/compiler/compileBroker.cpp
View File

@ -126,6 +126,7 @@ HS_DTRACE_PROBE_DECL9(hotspot, method__compile__end,
bool CompileBroker::_initialized = false;
volatile bool CompileBroker::_should_block = false;
volatile jint CompileBroker::_print_compilation_warning = 0;
volatile jint CompileBroker::_should_compile_new_jobs = run_compilation;
// The installed compiler(s)
@ -2027,11 +2028,10 @@ void CompileBroker::invoke_compiler_on_method(CompileTask* task) {
#endif
}
// ------------------------------------------------------------------
// CompileBroker::handle_full_code_cache
//
// The CodeCache is full. Print out warning and disable compilation or
// try code cache cleaning so compilation can continue later.
/**
* The CodeCache is full. Print out warning and disable compilation
* or try code cache cleaning so compilation can continue later.
*/
void CompileBroker::handle_full_code_cache() {
UseInterpreter = true;
if (UseCompiler || AlwaysCompileLoopMethods ) {
@ -2048,12 +2048,9 @@ void CompileBroker::handle_full_code_cache() {
xtty->stamp();
xtty->end_elem();
}
warning("CodeCache is full. Compiler has been disabled.");
warning("Try increasing the code cache size using -XX:ReservedCodeCacheSize=");
CodeCache::report_codemem_full();
#ifndef PRODUCT
if (CompileTheWorld || ExitOnFullCodeCache) {
codecache_print(/* detailed= */ true);
@ -2066,17 +2063,22 @@ void CompileBroker::handle_full_code_cache() {
// Since code cache is full, immediately stop new compiles
if (CompileBroker::set_should_compile_new_jobs(CompileBroker::stop_compilation)) {
NMethodSweeper::log_sweep("disable_compiler");
// Switch to 'vm_state'. This ensures that possibly_sweep() can be called
// without having to consider the state in which the current thread is.
ThreadInVMfromUnknown in_vm;
NMethodSweeper::possibly_sweep();
}
// Switch to 'vm_state'. This ensures that possibly_sweep() can be called
// without having to consider the state in which the current thread is.
ThreadInVMfromUnknown in_vm;
NMethodSweeper::possibly_sweep();
} else {
disable_compilation_forever();
}
// Print warning only once
if (should_print_compiler_warning()) {
warning("CodeCache is full. Compiler has been disabled.");
warning("Try increasing the code cache size using -XX:ReservedCodeCacheSize=");
codecache_print(/* detailed= */ true);
}
}
codecache_print(/* detailed= */ true);
}
// ------------------------------------------------------------------

8
hotspot/src/share/vm/compiler/compileBroker.hpp
View File

@ -315,6 +315,8 @@ class CompileBroker: AllStatic {
static int _sum_nmethod_code_size;
static long _peak_compilation_time;
static volatile jint _print_compilation_warning;
static CompilerThread* make_compiler_thread(const char* name, CompileQueue* queue, CompilerCounters* counters, AbstractCompiler* comp, TRAPS);
static void init_compiler_threads(int c1_compiler_count, int c2_compiler_count);
static bool compilation_is_complete (methodHandle method, int osr_bci, int comp_level);
@ -418,7 +420,11 @@ class CompileBroker: AllStatic {
return _should_compile_new_jobs == shutdown_compilaton;
}
static void handle_full_code_cache();
// Ensures that warning is only printed once.
static bool should_print_compiler_warning() {
jint old = Atomic::cmpxchg(1, &_print_compilation_warning, 0);
return old == 0;
}
// Return total compilation ticks
static jlong total_compilation_ticks() {
return _perf_total_compilation != NULL ? _perf_total_compilation->get_value() : 0;

8
hotspot/src/share/vm/runtime/arguments.cpp
View File

@ -1132,9 +1132,6 @@ void Arguments::set_tiered_flags() {
Tier3InvokeNotifyFreqLog = 0;
Tier4InvocationThreshold = 0;
}
if (FLAG_IS_DEFAULT(NmethodSweepFraction)) {
FLAG_SET_DEFAULT(NmethodSweepFraction, 1 + ReservedCodeCacheSize / (16 * M));
}
}
#if INCLUDE_ALL_GCS
@ -3643,6 +3640,11 @@ jint Arguments::apply_ergo() {
"Incompatible compilation policy selected", NULL);
}
}
// Set NmethodSweepFraction after the size of the code cache is adapted (in case of tiered)
if (FLAG_IS_DEFAULT(NmethodSweepFraction)) {
FLAG_SET_DEFAULT(NmethodSweepFraction, 1 + ReservedCodeCacheSize / (16 * M));
}
// Set heap size based on available physical memory
set_heap_size();

2
hotspot/src/share/vm/runtime/globals.hpp
View File

@ -3286,7 +3286,7 @@ class CommandLineFlags {
"Exit the VM if we fill the code cache") \
\
product(bool, UseCodeCacheFlushing, true, \
"Attempt to clean the code cache before shutting off compiler") \
"Remove cold/old nmethods from the code cache") \
\
/* interpreter debugging */ \
develop(intx, BinarySwitchThreshold, 5, \

205
hotspot/src/share/vm/runtime/sweeper.cpp
View File

@ -112,14 +112,13 @@ void NMethodSweeper::record_sweep(nmethod* nm, int line) {
if (_records != NULL) {
_records[_sweep_index].traversal = _traversals;
_records[_sweep_index].traversal_mark = nm->_stack_traversal_mark;
_records[_sweep_index].invocation = _invocations;
_records[_sweep_index].invocation = _sweep_fractions_left;
_records[_sweep_index].compile_id = nm->compile_id();
_records[_sweep_index].kind = nm->compile_kind();
_records[_sweep_index].state = nm->_state;
_records[_sweep_index].vep = nm->verified_entry_point();
_records[_sweep_index].uep = nm->entry_point();
_records[_sweep_index].line = line;
_sweep_index = (_sweep_index + 1) % SweeperLogEntries;
}
}
@ -127,26 +126,29 @@ void NMethodSweeper::record_sweep(nmethod* nm, int line) {
#define SWEEP(nm)
#endif
nmethod* NMethodSweeper::_current = NULL; // Current nmethod
long NMethodSweeper::_traversals = 0; // Nof. stack traversals performed
int NMethodSweeper::_seen = 0; // Nof. nmethods we have currently processed in current pass of CodeCache
int NMethodSweeper::_flushed_count = 0; // Nof. nmethods flushed in current sweep
int NMethodSweeper::_zombified_count = 0; // Nof. nmethods made zombie in current sweep
int NMethodSweeper::_marked_count = 0; // Nof. nmethods marked for reclaim in current sweep
nmethod* NMethodSweeper::_current = NULL; // Current nmethod
long NMethodSweeper::_traversals = 0; // Stack scan count, also sweep ID.
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
int NMethodSweeper::_flushed_count = 0; // Nof. nmethods flushed in current sweep
int NMethodSweeper::_zombified_count = 0; // Nof. nmethods made zombie in current sweep
int NMethodSweeper::_marked_for_reclamation_count = 0; // Nof. nmethods marked for reclaim in current sweep
volatile int NMethodSweeper::_invocations = 0; // Nof. invocations left until we are completed with this pass
volatile int NMethodSweeper::_sweep_started = 0; // Whether a sweep is in progress.
volatile bool NMethodSweeper::_should_sweep = true; // Indicates if we should invoke the sweeper
volatile int NMethodSweeper::_sweep_fractions_left = 0; // Nof. invocations left until we are completed with this pass
volatile int NMethodSweeper::_sweep_started = 0; // Flag to control conc sweeper
volatile int NMethodSweeper::_bytes_changed = 0; // Counts the total nmethod size if the nmethod changed from:
// 1) alive -> not_entrant
// 2) not_entrant -> zombie
// 3) zombie -> marked_for_reclamation
jint NMethodSweeper::_locked_seen = 0;
jint NMethodSweeper::_not_entrant_seen_on_stack = 0;
bool NMethodSweeper::_request_mark_phase = false;
int NMethodSweeper::_total_nof_methods_reclaimed = 0;
jlong NMethodSweeper::_total_time_sweeping = 0;
jlong NMethodSweeper::_total_time_this_sweep = 0;
jlong NMethodSweeper::_peak_sweep_time = 0;
jlong NMethodSweeper::_peak_sweep_fraction_time = 0;
int NMethodSweeper::_hotness_counter_reset_val = 0;
int NMethodSweeper::_total_nof_methods_reclaimed = 0; // Accumulated nof methods flushed
jlong NMethodSweeper::_total_time_sweeping = 0; // Accumulated time sweeping
jlong NMethodSweeper::_total_time_this_sweep = 0; // Total time this sweep
jlong NMethodSweeper::_peak_sweep_time = 0; // Peak time for a full sweep
jlong NMethodSweeper::_peak_sweep_fraction_time = 0; // Peak time sweeping one fraction
int NMethodSweeper::_hotness_counter_reset_val = 0;
class MarkActivationClosure: public CodeBlobClosure {
@ -197,13 +199,16 @@ void NMethodSweeper::mark_active_nmethods() {
return;
}
// Increase time so that we can estimate when to invoke the sweeper again.
_time_counter++;
// Check for restart
assert(CodeCache::find_blob_unsafe(_current) == _current, "Sweeper nmethod cached state invalid");
if (!sweep_in_progress() && need_marking_phase()) {
_seen = 0;
_invocations = NmethodSweepFraction;
_current = CodeCache::first_nmethod();
_traversals += 1;
if (!sweep_in_progress()) {
_seen = 0;
_sweep_fractions_left = NmethodSweepFraction;
_current = CodeCache::first_nmethod();
_traversals += 1;
_total_time_this_sweep = 0;
if (PrintMethodFlushing) {
@ -211,10 +216,6 @@ void NMethodSweeper::mark_active_nmethods() {
}
Threads::nmethods_do(&mark_activation_closure);
// reset the flags since we started a scan from the beginning.
reset_nmethod_marking();
_locked_seen = 0;
_not_entrant_seen_on_stack = 0;
} else {
// Only set hotness counter
Threads::nmethods_do(&set_hotness_closure);
@ -222,14 +223,48 @@ void NMethodSweeper::mark_active_nmethods() {
OrderAccess::storestore();
}
/**
* This function invokes the sweeper if at least one of the three conditions is met:
* (1) The code cache is getting full
* (2) There are sufficient state changes in/since the last sweep.
* (3) We have not been sweeping for 'some time'
*/
void NMethodSweeper::possibly_sweep() {
assert(JavaThread::current()->thread_state() == _thread_in_vm, "must run in vm mode");
if (!MethodFlushing || !sweep_in_progress()) {
return;
}
if (_invocations > 0) {
// If there was no state change while nmethod sweeping, 'should_sweep' will be false.
// This is one of the two places where should_sweep can be set to true. The general
// idea is as follows: If there is enough free space in the code cache, there is no
// need to invoke the sweeper. The following formula (which determines whether to invoke
// the sweeper or not) depends on the assumption that for larger ReservedCodeCacheSizes
// we need less frequent sweeps than for smaller ReservedCodecCacheSizes. Furthermore,
// the formula considers how much space in the code cache is currently used. Here are
// some examples that will (hopefully) help in understanding.
//
// Small ReservedCodeCacheSizes: (e.g., < 16M) We invoke the sweeper every time, since
// the result of the division is 0. This
// keeps the used code cache size small
// (important for embedded Java)
// Large ReservedCodeCacheSize : (e.g., 256M + code cache is 10% full). The formula
// computes: (256 / 16) - 1 = 15
// As a result, we invoke the sweeper after
// 15 invocations of 'mark_active_nmethods.
// Large ReservedCodeCacheSize: (e.g., 256M + code Cache is 90% full). The formula
// computes: (256 / 16) - 10 = 6.
if (!_should_sweep) {
int time_since_last_sweep = _time_counter - _last_sweep;
double wait_until_next_sweep = (ReservedCodeCacheSize / (16 * M)) - time_since_last_sweep -
CodeCache::reverse_free_ratio();
if ((wait_until_next_sweep <= 0.0) || !CompileBroker::should_compile_new_jobs()) {
_should_sweep = true;
}
}
if (_should_sweep && _sweep_fractions_left > 0) {
// Only one thread at a time will sweep
jint old = Atomic::cmpxchg( 1, &_sweep_started, 0 );
if (old != 0) {
@ -242,31 +277,46 @@ void NMethodSweeper::possibly_sweep() {
memset(_records, 0, sizeof(SweeperRecord) * SweeperLogEntries);
}
#endif
if (_invocations > 0) {
if (_sweep_fractions_left > 0) {
sweep_code_cache();
_invocations--;
_sweep_fractions_left--;
}
// We are done with sweeping the code cache once.
if (_sweep_fractions_left == 0) {
_last_sweep = _time_counter;
// Reset flag; temporarily disables sweeper
_should_sweep = false;
// If there was enough state change, 'possibly_enable_sweeper()'
// sets '_should_sweep' to true
possibly_enable_sweeper();
// Reset _bytes_changed only if there was enough state change. _bytes_changed
// can further increase by calls to 'report_state_change'.
if (_should_sweep) {
_bytes_changed = 0;
}
}
_sweep_started = 0;
}
}
void NMethodSweeper::sweep_code_cache() {
jlong sweep_start_counter = os::elapsed_counter();
_flushed_count = 0;
_zombified_count = 0;
_marked_count = 0;
_flushed_count = 0;
_zombified_count = 0;
_marked_for_reclamation_count = 0;
if (PrintMethodFlushing && Verbose) {
tty->print_cr("### Sweep at %d out of %d. Invocations left: %d", _seen, CodeCache::nof_nmethods(), _invocations);
tty->print_cr("### Sweep at %d out of %d. Invocations left: %d", _seen, CodeCache::nof_nmethods(), _sweep_fractions_left);
}
if (!CompileBroker::should_compile_new_jobs()) {
// If we have turned off compilations we might as well do full sweeps
// in order to reach the clean state faster. Otherwise the sleeping compiler
// threads will slow down sweeping.
_invocations = 1;
_sweep_fractions_left = 1;
}
// We want to visit all nmethods after NmethodSweepFraction
@ -274,7 +324,7 @@ void NMethodSweeper::sweep_code_cache() {
// remaining number of invocations. This is only an estimate since
// the number of nmethods changes during the sweep so the final
// stage must iterate until it there are no more nmethods.
int todo = (CodeCache::nof_nmethods() - _seen) / _invocations;
int todo = (CodeCache::nof_nmethods() - _seen) / _sweep_fractions_left;
int swept_count = 0;
@ -286,11 +336,11 @@ void NMethodSweeper::sweep_code_cache() {
MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
// The last invocation iterates until there are no more nmethods
for (int i = 0; (i < todo || _invocations == 1) && _current != NULL; i++) {
for (int i = 0; (i < todo || _sweep_fractions_left == 1) && _current != NULL; i++) {
swept_count++;
if (SafepointSynchronize::is_synchronizing()) { // Safepoint request
if (PrintMethodFlushing && Verbose) {
tty->print_cr("### Sweep at %d out of %d, invocation: %d, yielding to safepoint", _seen, CodeCache::nof_nmethods(), _invocations);
tty->print_cr("### Sweep at %d out of %d, invocation: %d, yielding to safepoint", _seen, CodeCache::nof_nmethods(), _sweep_fractions_left);
}
MutexUnlockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
@ -314,19 +364,7 @@ void NMethodSweeper::sweep_code_cache() {
}
}
assert(_invocations > 1 || _current == NULL, "must have scanned the whole cache");
if (!sweep_in_progress() && !need_marking_phase() && (_locked_seen || _not_entrant_seen_on_stack)) {
// we've completed a scan without making progress but there were
// nmethods we were unable to process either because they were
// locked or were still on stack. We don't have to aggressively
// clean them up so just stop scanning. We could scan once more
// but that complicates the control logic and it's unlikely to
// matter much.
if (PrintMethodFlushing) {
tty->print_cr("### Couldn't make progress on some nmethods so stopping sweep");
}
}
assert(_sweep_fractions_left > 1 || _current == NULL, "must have scanned the whole cache");
jlong sweep_end_counter = os::elapsed_counter();
jlong sweep_time = sweep_end_counter - sweep_start_counter;
@ -340,21 +378,21 @@ void NMethodSweeper::sweep_code_cache() {
event.set_starttime(sweep_start_counter);
event.set_endtime(sweep_end_counter);
event.set_sweepIndex(_traversals);
event.set_sweepFractionIndex(NmethodSweepFraction - _invocations + 1);
event.set_sweepFractionIndex(NmethodSweepFraction - _sweep_fractions_left + 1);
event.set_sweptCount(swept_count);
event.set_flushedCount(_flushed_count);
event.set_markedCount(_marked_count);
event.set_markedCount(_marked_for_reclamation_count);
event.set_zombifiedCount(_zombified_count);
event.commit();
}
#ifdef ASSERT
if(PrintMethodFlushing) {
tty->print_cr("### sweeper: sweep time(%d): " INT64_FORMAT, _invocations, (jlong)sweep_time);
tty->print_cr("### sweeper: sweep time(%d): " INT64_FORMAT, _sweep_fractions_left, (jlong)sweep_time);
}
#endif
if (_invocations == 1) {
if (_sweep_fractions_left == 1) {
_peak_sweep_time = MAX2(_peak_sweep_time, _total_time_this_sweep);
log_sweep("finished");
}
@ -368,12 +406,37 @@ void NMethodSweeper::sweep_code_cache() {
// it only makes sense to re-enable compilation if we have actually freed memory.
// Note that typically several kB are released for sweeping 16MB of the code
// cache. As a result, 'freed_memory' > 0 to restart the compiler.
if (UseCodeCacheFlushing && (!CompileBroker::should_compile_new_jobs() && (freed_memory > 0))) {
if (!CompileBroker::should_compile_new_jobs() && (freed_memory > 0)) {
CompileBroker::set_should_compile_new_jobs(CompileBroker::run_compilation);
log_sweep("restart_compiler");
}
}
/**
* This function updates the sweeper statistics that keep track of nmethods
* state changes. If there is 'enough' state change, the sweeper is invoked
* as soon as possible. There can be data races on _bytes_changed. The data
* races are benign, since it does not matter if we loose a couple of bytes.
* In the worst case we call the sweeper a little later. Also, we are guaranteed
* to invoke the sweeper if the code cache gets full.
*/
void NMethodSweeper::report_state_change(nmethod* nm) {
_bytes_changed += nm->total_size();
possibly_enable_sweeper();
}
/**
* Function determines if there was 'enough' state change in the code cache to invoke
* the sweeper again. Currently, we determine 'enough' as more than 1% state change in
* the code cache since the last sweep.
*/
void NMethodSweeper::possibly_enable_sweeper() {
double percent_changed = ((double)_bytes_changed / (double)ReservedCodeCacheSize) * 100;
if (percent_changed > 1.0) {
_should_sweep = true;
}
}
class NMethodMarker: public StackObj {
private:
CompilerThread* _thread;
@ -424,9 +487,6 @@ int NMethodSweeper::process_nmethod(nmethod *nm) {
MutexLocker cl(CompiledIC_lock);
nm->cleanup_inline_caches();
SWEEP(nm);
} else {
_locked_seen++;
SWEEP(nm);
}
return freed_memory;
}
@ -448,8 +508,9 @@ int NMethodSweeper::process_nmethod(nmethod *nm) {
tty->print_cr("### Nmethod %3d/" PTR_FORMAT " (zombie) being marked for reclamation", nm->compile_id(), nm);
}
nm->mark_for_reclamation();
request_nmethod_marking();
_marked_count++;
// Keep track of code cache state change
_bytes_changed += nm->total_size();
_marked_for_reclamation_count++;
SWEEP(nm);
}
} else if (nm->is_not_entrant()) {
@ -459,18 +520,14 @@ int NMethodSweeper::process_nmethod(nmethod *nm) {
if (PrintMethodFlushing && Verbose) {
tty->print_cr("### Nmethod %3d/" PTR_FORMAT " (not entrant) being made zombie", nm->compile_id(), nm);
}
// Code cache state change is tracked in make_zombie()
nm->make_zombie();
request_nmethod_marking();
_zombified_count++;
SWEEP(nm);
} else {
// Still alive, clean up its inline caches
MutexLocker cl(CompiledIC_lock);
nm->cleanup_inline_caches();
// we coudn't transition this nmethod so don't immediately
// request a rescan. If this method stays on the stack for a
// long time we don't want to keep rescanning the code cache.
_not_entrant_seen_on_stack++;
SWEEP(nm);
}
} else if (nm->is_unloaded()) {
@ -485,8 +542,8 @@ int NMethodSweeper::process_nmethod(nmethod *nm) {
release_nmethod(nm);
_flushed_count++;
} else {
// Code cache state change is tracked in make_zombie()
nm->make_zombie();
request_nmethod_marking();
_zombified_count++;
SWEEP(nm);
}
@ -514,7 +571,11 @@ int NMethodSweeper::process_nmethod(nmethod *nm) {
// The second condition ensures that methods are not immediately made not-entrant
// after compilation.
nm->make_not_entrant();
request_nmethod_marking();
// Code cache state change is tracked in make_not_entrant()
if (PrintMethodFlushing && Verbose) {
tty->print_cr("### Nmethod %d/" PTR_FORMAT "made not-entrant: hotness counter %d/%d threshold %f",
nm->compile_id(), nm, nm->hotness_counter(), reset_val, threshold);
}
}
}
}

42
hotspot/src/share/vm/runtime/sweeper.hpp
View File

@ -53,22 +53,22 @@
// is full.
class NMethodSweeper : public AllStatic {
static long _traversals; // Stack scan count, also sweep ID.
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_count; // Nof. nmethods marked for reclaim in current sweep
static volatile int _invocations; // No. of invocations left until we are completed with this pass
static volatile int _sweep_started; // Flag to control conc sweeper
//The following are reset in mark_active_nmethods and synchronized by the safepoint
static bool _request_mark_phase; // Indicates that a change has happend and we need another mark pahse,
// always checked and reset at a safepoint so memory will be in sync.
static int _locked_seen; // Number of locked nmethods encountered during the scan
static int _not_entrant_seen_on_stack; // Number of not entrant nmethod were are still on stack
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 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 jlong _total_time_sweeping; // Accumulated time sweeping
@ -81,9 +81,6 @@ class NMethodSweeper : public AllStatic {
static bool sweep_in_progress();
static void sweep_code_cache();
static void request_nmethod_marking() { _request_mark_phase = true; }
static void reset_nmethod_marking() { _request_mark_phase = false; }
static bool need_marking_phase() { return _request_mark_phase; }
static int _hotness_counter_reset_val;
@ -109,13 +106,8 @@ class NMethodSweeper : public AllStatic {
static int sort_nmethods_by_hotness(nmethod** nm1, nmethod** nm2);
static int hotness_counter_reset_val();
static void notify() {
// Request a new sweep of the code cache from the beginning. No
// need to synchronize the setting of this flag since it only
// changes to false at safepoint so we can never overwrite it with false.
request_nmethod_marking();
}
static void report_state_change(nmethod* nm);
static void possibly_enable_sweeper();
};
#endif // SHARE_VM_RUNTIME_SWEEPER_HPP