--- a/src/hotspot/share/runtime/tieredThresholdPolicy.cpp Mon Oct 07 16:48:42 2019 +0200
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,1005 +0,0 @@
-/*
- * Copyright (c) 2010, 2019, Oracle and/or its affiliates. All rights reserved.
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
- *
- * This code is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation.
- *
- * This code is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- *
- */
-
-#include "precompiled.hpp"
-#include "compiler/compileBroker.hpp"
-#include "compiler/compilerOracle.hpp"
-#include "memory/resourceArea.hpp"
-#include "runtime/arguments.hpp"
-#include "runtime/handles.inline.hpp"
-#include "runtime/safepoint.hpp"
-#include "runtime/safepointVerifiers.hpp"
-#include "runtime/tieredThresholdPolicy.hpp"
-#include "code/scopeDesc.hpp"
-#include "oops/method.inline.hpp"
-#if INCLUDE_JVMCI
-#include "jvmci/jvmci.hpp"
-#endif
-
-#ifdef TIERED
-
-#include "c1/c1_Compiler.hpp"
-#include "opto/c2compiler.hpp"
-
-template<CompLevel level>
-bool TieredThresholdPolicy::call_predicate_helper(int i, int b, double scale, Method* method) {
- double threshold_scaling;
- if (CompilerOracle::has_option_value(method, "CompileThresholdScaling", threshold_scaling)) {
- scale *= threshold_scaling;
- }
- switch(level) {
- case CompLevel_aot:
- return (i >= Tier3AOTInvocationThreshold * scale) ||
- (i >= Tier3AOTMinInvocationThreshold * scale && i + b >= Tier3AOTCompileThreshold * scale);
- case CompLevel_none:
- case CompLevel_limited_profile:
- return (i >= Tier3InvocationThreshold * scale) ||
- (i >= Tier3MinInvocationThreshold * scale && i + b >= Tier3CompileThreshold * scale);
- case CompLevel_full_profile:
- return (i >= Tier4InvocationThreshold * scale) ||
- (i >= Tier4MinInvocationThreshold * scale && i + b >= Tier4CompileThreshold * scale);
- }
- return true;
-}
-
-template<CompLevel level>
-bool TieredThresholdPolicy::loop_predicate_helper(int i, int b, double scale, Method* method) {
- double threshold_scaling;
- if (CompilerOracle::has_option_value(method, "CompileThresholdScaling", threshold_scaling)) {
- scale *= threshold_scaling;
- }
- switch(level) {
- case CompLevel_aot:
- return b >= Tier3AOTBackEdgeThreshold * scale;
- case CompLevel_none:
- case CompLevel_limited_profile:
- return b >= Tier3BackEdgeThreshold * scale;
- case CompLevel_full_profile:
- return b >= Tier4BackEdgeThreshold * scale;
- }
- return true;
-}
-
-// Simple methods are as good being compiled with C1 as C2.
-// Determine if a given method is such a case.
-bool TieredThresholdPolicy::is_trivial(Method* method) {
- if (method->is_accessor() ||
- method->is_constant_getter()) {
- return true;
- }
- return false;
-}
-
-bool TieredThresholdPolicy::should_compile_at_level_simple(Method* method) {
- if (TieredThresholdPolicy::is_trivial(method)) {
- return true;
- }
-#if INCLUDE_JVMCI
- if (UseJVMCICompiler) {
- AbstractCompiler* comp = CompileBroker::compiler(CompLevel_full_optimization);
- if (comp != NULL && comp->is_jvmci() && ((JVMCICompiler*) comp)->force_comp_at_level_simple(method)) {
- return true;
- }
- }
-#endif
- return false;
-}
-
-CompLevel TieredThresholdPolicy::comp_level(Method* method) {
- CompiledMethod *nm = method->code();
- if (nm != NULL && nm->is_in_use()) {
- return (CompLevel)nm->comp_level();
- }
- return CompLevel_none;
-}
-
-void TieredThresholdPolicy::print_counters(const char* prefix, const methodHandle& mh) {
- int invocation_count = mh->invocation_count();
- int backedge_count = mh->backedge_count();
- MethodData* mdh = mh->method_data();
- int mdo_invocations = 0, mdo_backedges = 0;
- int mdo_invocations_start = 0, mdo_backedges_start = 0;
- if (mdh != NULL) {
- mdo_invocations = mdh->invocation_count();
- mdo_backedges = mdh->backedge_count();
- mdo_invocations_start = mdh->invocation_count_start();
- mdo_backedges_start = mdh->backedge_count_start();
- }
- tty->print(" %stotal=%d,%d %smdo=%d(%d),%d(%d)", prefix,
- invocation_count, backedge_count, prefix,
- mdo_invocations, mdo_invocations_start,
- mdo_backedges, mdo_backedges_start);
- tty->print(" %smax levels=%d,%d", prefix,
- mh->highest_comp_level(), mh->highest_osr_comp_level());
-}
-
-// Print an event.
-void TieredThresholdPolicy::print_event(EventType type, const methodHandle& mh, const methodHandle& imh,
- int bci, CompLevel level) {
- bool inlinee_event = mh() != imh();
-
- ttyLocker tty_lock;
- tty->print("%lf: [", os::elapsedTime());
-
- switch(type) {
- case CALL:
- tty->print("call");
- break;
- case LOOP:
- tty->print("loop");
- break;
- case COMPILE:
- tty->print("compile");
- break;
- case REMOVE_FROM_QUEUE:
- tty->print("remove-from-queue");
- break;
- case UPDATE_IN_QUEUE:
- tty->print("update-in-queue");
- break;
- case REPROFILE:
- tty->print("reprofile");
- break;
- case MAKE_NOT_ENTRANT:
- tty->print("make-not-entrant");
- break;
- default:
- tty->print("unknown");
- }
-
- tty->print(" level=%d ", level);
-
- ResourceMark rm;
- char *method_name = mh->name_and_sig_as_C_string();
- tty->print("[%s", method_name);
- if (inlinee_event) {
- char *inlinee_name = imh->name_and_sig_as_C_string();
- tty->print(" [%s]] ", inlinee_name);
- }
- else tty->print("] ");
- tty->print("@%d queues=%d,%d", bci, CompileBroker::queue_size(CompLevel_full_profile),
- CompileBroker::queue_size(CompLevel_full_optimization));
-
- print_specific(type, mh, imh, bci, level);
-
- if (type != COMPILE) {
- print_counters("", mh);
- if (inlinee_event) {
- print_counters("inlinee ", imh);
- }
- tty->print(" compilable=");
- bool need_comma = false;
- if (!mh->is_not_compilable(CompLevel_full_profile)) {
- tty->print("c1");
- need_comma = true;
- }
- if (!mh->is_not_osr_compilable(CompLevel_full_profile)) {
- if (need_comma) tty->print(",");
- tty->print("c1-osr");
- need_comma = true;
- }
- if (!mh->is_not_compilable(CompLevel_full_optimization)) {
- if (need_comma) tty->print(",");
- tty->print("c2");
- need_comma = true;
- }
- if (!mh->is_not_osr_compilable(CompLevel_full_optimization)) {
- if (need_comma) tty->print(",");
- tty->print("c2-osr");
- }
- tty->print(" status=");
- if (mh->queued_for_compilation()) {
- tty->print("in-queue");
- } else tty->print("idle");
- }
- tty->print_cr("]");
-}
-
-void TieredThresholdPolicy::initialize() {
- int count = CICompilerCount;
- bool c1_only = TieredStopAtLevel < CompLevel_full_optimization;
-#ifdef _LP64
- // Turn on ergonomic compiler count selection
- if (FLAG_IS_DEFAULT(CICompilerCountPerCPU) && FLAG_IS_DEFAULT(CICompilerCount)) {
- FLAG_SET_DEFAULT(CICompilerCountPerCPU, true);
- }
- if (CICompilerCountPerCPU) {
- // Simple log n seems to grow too slowly for tiered, try something faster: log n * log log n
- int log_cpu = log2_int(os::active_processor_count());
- int loglog_cpu = log2_int(MAX2(log_cpu, 1));
- count = MAX2(log_cpu * loglog_cpu * 3 / 2, 2);
- // Make sure there is enough space in the code cache to hold all the compiler buffers
- size_t c1_size = Compiler::code_buffer_size();
- size_t c2_size = C2Compiler::initial_code_buffer_size();
- size_t buffer_size = c1_only ? c1_size : (c1_size/3 + 2*c2_size/3);
- int max_count = (ReservedCodeCacheSize - (CodeCacheMinimumUseSpace DEBUG_ONLY(* 3))) / (int)buffer_size;
- if (count > max_count) {
- // Lower the compiler count such that all buffers fit into the code cache
- count = MAX2(max_count, c1_only ? 1 : 2);
- }
- FLAG_SET_ERGO(CICompilerCount, count);
- }
-#else
- // On 32-bit systems, the number of compiler threads is limited to 3.
- // On these systems, the virtual address space available to the JVM
- // is usually limited to 2-4 GB (the exact value depends on the platform).
- // As the compilers (especially C2) can consume a large amount of
- // memory, scaling the number of compiler threads with the number of
- // available cores can result in the exhaustion of the address space
- /// available to the VM and thus cause the VM to crash.
- if (FLAG_IS_DEFAULT(CICompilerCount)) {
- count = 3;
- FLAG_SET_ERGO(CICompilerCount, count);
- }
-#endif
-
- if (c1_only) {
- // No C2 compiler thread required
- set_c1_count(count);
- } else {
- set_c1_count(MAX2(count / 3, 1));
- set_c2_count(MAX2(count - c1_count(), 1));
- }
- assert(count == c1_count() + c2_count(), "inconsistent compiler thread count");
-
- // Some inlining tuning
-#ifdef X86
- if (FLAG_IS_DEFAULT(InlineSmallCode)) {
- FLAG_SET_DEFAULT(InlineSmallCode, 2000);
- }
-#endif
-
-#if defined SPARC || defined AARCH64
- if (FLAG_IS_DEFAULT(InlineSmallCode)) {
- FLAG_SET_DEFAULT(InlineSmallCode, 2500);
- }
-#endif
-
- set_increase_threshold_at_ratio();
- set_start_time(os::javaTimeMillis());
-}
-
-void TieredThresholdPolicy::set_carry_if_necessary(InvocationCounter *counter) {
- if (!counter->carry() && counter->count() > InvocationCounter::count_limit / 2) {
- counter->set_carry_flag();
- }
-}
-
-// Set carry flags on the counters if necessary
-void TieredThresholdPolicy::handle_counter_overflow(Method* method) {
- MethodCounters *mcs = method->method_counters();
- if (mcs != NULL) {
- set_carry_if_necessary(mcs->invocation_counter());
- set_carry_if_necessary(mcs->backedge_counter());
- }
- MethodData* mdo = method->method_data();
- if (mdo != NULL) {
- set_carry_if_necessary(mdo->invocation_counter());
- set_carry_if_necessary(mdo->backedge_counter());
- }
-}
-
-// Called with the queue locked and with at least one element
-CompileTask* TieredThresholdPolicy::select_task(CompileQueue* compile_queue) {
- CompileTask *max_blocking_task = NULL;
- CompileTask *max_task = NULL;
- Method* max_method = NULL;
- jlong t = os::javaTimeMillis();
- // Iterate through the queue and find a method with a maximum rate.
- for (CompileTask* task = compile_queue->first(); task != NULL;) {
- CompileTask* next_task = task->next();
- Method* method = task->method();
- // If a method was unloaded or has been stale for some time, remove it from the queue.
- // Blocking tasks and tasks submitted from whitebox API don't become stale
- if (task->is_unloaded() || (task->can_become_stale() && is_stale(t, TieredCompileTaskTimeout, method) && !is_old(method))) {
- if (!task->is_unloaded()) {
- if (PrintTieredEvents) {
- print_event(REMOVE_FROM_QUEUE, method, method, task->osr_bci(), (CompLevel) task->comp_level());
- }
- method->clear_queued_for_compilation();
- }
- compile_queue->remove_and_mark_stale(task);
- task = next_task;
- continue;
- }
- update_rate(t, method);
- if (max_task == NULL || compare_methods(method, max_method)) {
- // Select a method with the highest rate
- max_task = task;
- max_method = method;
- }
-
- if (task->is_blocking()) {
- if (max_blocking_task == NULL || compare_methods(method, max_blocking_task->method())) {
- max_blocking_task = task;
- }
- }
-
- task = next_task;
- }
-
- if (max_blocking_task != NULL) {
- // In blocking compilation mode, the CompileBroker will make
- // compilations submitted by a JVMCI compiler thread non-blocking. These
- // compilations should be scheduled after all blocking compilations
- // to service non-compiler related compilations sooner and reduce the
- // chance of such compilations timing out.
- max_task = max_blocking_task;
- max_method = max_task->method();
- }
-
- if (max_task != NULL && max_task->comp_level() == CompLevel_full_profile &&
- TieredStopAtLevel > CompLevel_full_profile &&
- max_method != NULL && is_method_profiled(max_method)) {
- max_task->set_comp_level(CompLevel_limited_profile);
-
- if (CompileBroker::compilation_is_complete(max_method, max_task->osr_bci(), CompLevel_limited_profile)) {
- if (PrintTieredEvents) {
- print_event(REMOVE_FROM_QUEUE, max_method, max_method, max_task->osr_bci(), (CompLevel)max_task->comp_level());
- }
- compile_queue->remove_and_mark_stale(max_task);
- max_method->clear_queued_for_compilation();
- return NULL;
- }
-
- if (PrintTieredEvents) {
- print_event(UPDATE_IN_QUEUE, max_method, max_method, max_task->osr_bci(), (CompLevel)max_task->comp_level());
- }
- }
-
- return max_task;
-}
-
-void TieredThresholdPolicy::reprofile(ScopeDesc* trap_scope, bool is_osr) {
- for (ScopeDesc* sd = trap_scope;; sd = sd->sender()) {
- if (PrintTieredEvents) {
- methodHandle mh(sd->method());
- print_event(REPROFILE, mh, mh, InvocationEntryBci, CompLevel_none);
- }
- MethodData* mdo = sd->method()->method_data();
- if (mdo != NULL) {
- mdo->reset_start_counters();
- }
- if (sd->is_top()) break;
- }
-}
-
-nmethod* TieredThresholdPolicy::event(const methodHandle& method, const methodHandle& inlinee,
- int branch_bci, int bci, CompLevel comp_level, CompiledMethod* nm, JavaThread* thread) {
- if (comp_level == CompLevel_none &&
- JvmtiExport::can_post_interpreter_events() &&
- thread->is_interp_only_mode()) {
- return NULL;
- }
- if (ReplayCompiles) {
- // Don't trigger other compiles in testing mode
- return NULL;
- }
-
- handle_counter_overflow(method());
- if (method() != inlinee()) {
- handle_counter_overflow(inlinee());
- }
-
- if (PrintTieredEvents) {
- print_event(bci == InvocationEntryBci ? CALL : LOOP, method, inlinee, bci, comp_level);
- }
-
- if (bci == InvocationEntryBci) {
- method_invocation_event(method, inlinee, comp_level, nm, thread);
- } else {
- // method == inlinee if the event originated in the main method
- method_back_branch_event(method, inlinee, bci, comp_level, nm, thread);
- // Check if event led to a higher level OSR compilation
- CompLevel expected_comp_level = comp_level;
- if (inlinee->is_not_osr_compilable(expected_comp_level)) {
- // It's not possble to reach the expected level so fall back to simple.
- expected_comp_level = CompLevel_simple;
- }
- nmethod* osr_nm = inlinee->lookup_osr_nmethod_for(bci, expected_comp_level, false);
- assert(osr_nm == NULL || osr_nm->comp_level() >= expected_comp_level, "lookup_osr_nmethod_for is broken");
- if (osr_nm != NULL) {
- // Perform OSR with new nmethod
- return osr_nm;
- }
- }
- return NULL;
-}
-
-// Check if the method can be compiled, change level if necessary
-void TieredThresholdPolicy::compile(const methodHandle& mh, int bci, CompLevel level, JavaThread* thread) {
- assert(level <= TieredStopAtLevel, "Invalid compilation level");
- if (level == CompLevel_none) {
- return;
- }
- if (level == CompLevel_aot) {
- if (mh->has_aot_code()) {
- if (PrintTieredEvents) {
- print_event(COMPILE, mh, mh, bci, level);
- }
- MutexLocker ml(Compile_lock);
- NoSafepointVerifier nsv;
- if (mh->has_aot_code() && mh->code() != mh->aot_code()) {
- mh->aot_code()->make_entrant();
- if (mh->has_compiled_code()) {
- mh->code()->make_not_entrant();
- }
- MutexLocker pl(CompiledMethod_lock, Mutex::_no_safepoint_check_flag);
- Method::set_code(mh, mh->aot_code());
- }
- }
- return;
- }
-
- // Check if the method can be compiled. If it cannot be compiled with C1, continue profiling
- // in the interpreter and then compile with C2 (the transition function will request that,
- // see common() ). If the method cannot be compiled with C2 but still can with C1, compile it with
- // pure C1.
- if ((bci == InvocationEntryBci && !can_be_compiled(mh, level))) {
- if (level == CompLevel_full_optimization && can_be_compiled(mh, CompLevel_simple)) {
- compile(mh, bci, CompLevel_simple, thread);
- }
- return;
- }
- if ((bci != InvocationEntryBci && !can_be_osr_compiled(mh, level))) {
- if (level == CompLevel_full_optimization && can_be_osr_compiled(mh, CompLevel_simple)) {
- nmethod* osr_nm = mh->lookup_osr_nmethod_for(bci, CompLevel_simple, false);
- if (osr_nm != NULL && osr_nm->comp_level() > CompLevel_simple) {
- // Invalidate the existing OSR nmethod so that a compile at CompLevel_simple is permitted.
- osr_nm->make_not_entrant();
- }
- compile(mh, bci, CompLevel_simple, thread);
- }
- return;
- }
- if (bci != InvocationEntryBci && mh->is_not_osr_compilable(level)) {
- return;
- }
- if (!CompileBroker::compilation_is_in_queue(mh)) {
- if (PrintTieredEvents) {
- print_event(COMPILE, mh, mh, bci, level);
- }
- submit_compile(mh, bci, level, thread);
- }
-}
-
-// Update the rate and submit compile
-void TieredThresholdPolicy::submit_compile(const methodHandle& mh, int bci, CompLevel level, JavaThread* thread) {
- int hot_count = (bci == InvocationEntryBci) ? mh->invocation_count() : mh->backedge_count();
- update_rate(os::javaTimeMillis(), mh());
- CompileBroker::compile_method(mh, bci, level, mh, hot_count, CompileTask::Reason_Tiered, thread);
-}
-
-// Print an event.
-void TieredThresholdPolicy::print_specific(EventType type, const methodHandle& mh, const methodHandle& imh,
- int bci, CompLevel level) {
- tty->print(" rate=");
- if (mh->prev_time() == 0) tty->print("n/a");
- else tty->print("%f", mh->rate());
-
- tty->print(" k=%.2lf,%.2lf", threshold_scale(CompLevel_full_profile, Tier3LoadFeedback),
- threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback));
-
-}
-
-// update_rate() is called from select_task() while holding a compile queue lock.
-void TieredThresholdPolicy::update_rate(jlong t, Method* m) {
- // Skip update if counters are absent.
- // Can't allocate them since we are holding compile queue lock.
- if (m->method_counters() == NULL) return;
-
- if (is_old(m)) {
- // We don't remove old methods from the queue,
- // so we can just zero the rate.
- m->set_rate(0);
- return;
- }
-
- // We don't update the rate if we've just came out of a safepoint.
- // delta_s is the time since last safepoint in milliseconds.
- jlong delta_s = t - SafepointTracing::end_of_last_safepoint_epoch_ms();
- jlong delta_t = t - (m->prev_time() != 0 ? m->prev_time() : start_time()); // milliseconds since the last measurement
- // How many events were there since the last time?
- int event_count = m->invocation_count() + m->backedge_count();
- int delta_e = event_count - m->prev_event_count();
-
- // We should be running for at least 1ms.
- if (delta_s >= TieredRateUpdateMinTime) {
- // And we must've taken the previous point at least 1ms before.
- if (delta_t >= TieredRateUpdateMinTime && delta_e > 0) {
- m->set_prev_time(t);
- m->set_prev_event_count(event_count);
- m->set_rate((float)delta_e / (float)delta_t); // Rate is events per millisecond
- } else {
- if (delta_t > TieredRateUpdateMaxTime && delta_e == 0) {
- // If nothing happened for 25ms, zero the rate. Don't modify prev values.
- m->set_rate(0);
- }
- }
- }
-}
-
-// Check if this method has been stale for a given number of milliseconds.
-// See select_task().
-bool TieredThresholdPolicy::is_stale(jlong t, jlong timeout, Method* m) {
- jlong delta_s = t - SafepointTracing::end_of_last_safepoint_epoch_ms();
- jlong delta_t = t - m->prev_time();
- if (delta_t > timeout && delta_s > timeout) {
- int event_count = m->invocation_count() + m->backedge_count();
- int delta_e = event_count - m->prev_event_count();
- // Return true if there were no events.
- return delta_e == 0;
- }
- return false;
-}
-
-// We don't remove old methods from the compile queue even if they have
-// very low activity. See select_task().
-bool TieredThresholdPolicy::is_old(Method* method) {
- return method->invocation_count() > 50000 || method->backedge_count() > 500000;
-}
-
-double TieredThresholdPolicy::weight(Method* method) {
- return (double)(method->rate() + 1) *
- (method->invocation_count() + 1) * (method->backedge_count() + 1);
-}
-
-// Apply heuristics and return true if x should be compiled before y
-bool TieredThresholdPolicy::compare_methods(Method* x, Method* y) {
- if (x->highest_comp_level() > y->highest_comp_level()) {
- // recompilation after deopt
- return true;
- } else
- if (x->highest_comp_level() == y->highest_comp_level()) {
- if (weight(x) > weight(y)) {
- return true;
- }
- }
- return false;
-}
-
-// Is method profiled enough?
-bool TieredThresholdPolicy::is_method_profiled(Method* method) {
- MethodData* mdo = method->method_data();
- if (mdo != NULL) {
- int i = mdo->invocation_count_delta();
- int b = mdo->backedge_count_delta();
- return call_predicate_helper<CompLevel_full_profile>(i, b, 1, method);
- }
- return false;
-}
-
-double TieredThresholdPolicy::threshold_scale(CompLevel level, int feedback_k) {
- double queue_size = CompileBroker::queue_size(level);
- int comp_count = compiler_count(level);
- double k = queue_size / (feedback_k * comp_count) + 1;
-
- // Increase C1 compile threshold when the code cache is filled more
- // than specified by IncreaseFirstTierCompileThresholdAt percentage.
- // The main intention is to keep enough free space for C2 compiled code
- // to achieve peak performance if the code cache is under stress.
- if ((TieredStopAtLevel == CompLevel_full_optimization) && (level != CompLevel_full_optimization)) {
- double current_reverse_free_ratio = CodeCache::reverse_free_ratio(CodeCache::get_code_blob_type(level));
- if (current_reverse_free_ratio > _increase_threshold_at_ratio) {
- k *= exp(current_reverse_free_ratio - _increase_threshold_at_ratio);
- }
- }
- return k;
-}
-
-// Call and loop predicates determine whether a transition to a higher
-// compilation level should be performed (pointers to predicate functions
-// are passed to common()).
-// Tier?LoadFeedback is basically a coefficient that determines of
-// how many methods per compiler thread can be in the queue before
-// the threshold values double.
-bool TieredThresholdPolicy::loop_predicate(int i, int b, CompLevel cur_level, Method* method) {
- switch(cur_level) {
- case CompLevel_aot: {
- double k = threshold_scale(CompLevel_full_profile, Tier3LoadFeedback);
- return loop_predicate_helper<CompLevel_aot>(i, b, k, method);
- }
- case CompLevel_none:
- case CompLevel_limited_profile: {
- double k = threshold_scale(CompLevel_full_profile, Tier3LoadFeedback);
- return loop_predicate_helper<CompLevel_none>(i, b, k, method);
- }
- case CompLevel_full_profile: {
- double k = threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback);
- return loop_predicate_helper<CompLevel_full_profile>(i, b, k, method);
- }
- default:
- return true;
- }
-}
-
-bool TieredThresholdPolicy::call_predicate(int i, int b, CompLevel cur_level, Method* method) {
- switch(cur_level) {
- case CompLevel_aot: {
- double k = threshold_scale(CompLevel_full_profile, Tier3LoadFeedback);
- return call_predicate_helper<CompLevel_aot>(i, b, k, method);
- }
- case CompLevel_none:
- case CompLevel_limited_profile: {
- double k = threshold_scale(CompLevel_full_profile, Tier3LoadFeedback);
- return call_predicate_helper<CompLevel_none>(i, b, k, method);
- }
- case CompLevel_full_profile: {
- double k = threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback);
- return call_predicate_helper<CompLevel_full_profile>(i, b, k, method);
- }
- default:
- return true;
- }
-}
-
-// Determine is a method is mature.
-bool TieredThresholdPolicy::is_mature(Method* method) {
- if (should_compile_at_level_simple(method)) return true;
- MethodData* mdo = method->method_data();
- if (mdo != NULL) {
- int i = mdo->invocation_count();
- int b = mdo->backedge_count();
- double k = ProfileMaturityPercentage / 100.0;
- return call_predicate_helper<CompLevel_full_profile>(i, b, k, method) ||
- loop_predicate_helper<CompLevel_full_profile>(i, b, k, method);
- }
- return false;
-}
-
-// If a method is old enough and is still in the interpreter we would want to
-// start profiling without waiting for the compiled method to arrive.
-// We also take the load on compilers into the account.
-bool TieredThresholdPolicy::should_create_mdo(Method* method, CompLevel cur_level) {
- if (cur_level == CompLevel_none &&
- CompileBroker::queue_size(CompLevel_full_optimization) <=
- Tier3DelayOn * compiler_count(CompLevel_full_optimization)) {
- int i = method->invocation_count();
- int b = method->backedge_count();
- double k = Tier0ProfilingStartPercentage / 100.0;
- return call_predicate_helper<CompLevel_none>(i, b, k, method) || loop_predicate_helper<CompLevel_none>(i, b, k, method);
- }
- return false;
-}
-
-// Inlining control: if we're compiling a profiled method with C1 and the callee
-// is known to have OSRed in a C2 version, don't inline it.
-bool TieredThresholdPolicy::should_not_inline(ciEnv* env, ciMethod* callee) {
- CompLevel comp_level = (CompLevel)env->comp_level();
- if (comp_level == CompLevel_full_profile ||
- comp_level == CompLevel_limited_profile) {
- return callee->highest_osr_comp_level() == CompLevel_full_optimization;
- }
- return false;
-}
-
-// Create MDO if necessary.
-void TieredThresholdPolicy::create_mdo(const methodHandle& mh, JavaThread* THREAD) {
- if (mh->is_native() ||
- mh->is_abstract() ||
- mh->is_accessor() ||
- mh->is_constant_getter()) {
- return;
- }
- if (mh->method_data() == NULL) {
- Method::build_interpreter_method_data(mh, CHECK_AND_CLEAR);
- }
-}
-
-
-/*
- * Method states:
- * 0 - interpreter (CompLevel_none)
- * 1 - pure C1 (CompLevel_simple)
- * 2 - C1 with invocation and backedge counting (CompLevel_limited_profile)
- * 3 - C1 with full profiling (CompLevel_full_profile)
- * 4 - C2 (CompLevel_full_optimization)
- *
- * Common state transition patterns:
- * a. 0 -> 3 -> 4.
- * The most common path. But note that even in this straightforward case
- * profiling can start at level 0 and finish at level 3.
- *
- * b. 0 -> 2 -> 3 -> 4.
- * This case occurs when the load on C2 is deemed too high. So, instead of transitioning
- * into state 3 directly and over-profiling while a method is in the C2 queue we transition to
- * level 2 and wait until the load on C2 decreases. This path is disabled for OSRs.
- *
- * c. 0 -> (3->2) -> 4.
- * In this case we enqueue a method for compilation at level 3, but the C1 queue is long enough
- * to enable the profiling to fully occur at level 0. In this case we change the compilation level
- * of the method to 2 while the request is still in-queue, because it'll allow it to run much faster
- * without full profiling while c2 is compiling.
- *
- * d. 0 -> 3 -> 1 or 0 -> 2 -> 1.
- * After a method was once compiled with C1 it can be identified as trivial and be compiled to
- * level 1. These transition can also occur if a method can't be compiled with C2 but can with C1.
- *
- * e. 0 -> 4.
- * This can happen if a method fails C1 compilation (it will still be profiled in the interpreter)
- * or because of a deopt that didn't require reprofiling (compilation won't happen in this case because
- * the compiled version already exists).
- *
- * Note that since state 0 can be reached from any other state via deoptimization different loops
- * are possible.
- *
- */
-
-// Common transition function. Given a predicate determines if a method should transition to another level.
-CompLevel TieredThresholdPolicy::common(Predicate p, Method* method, CompLevel cur_level, bool disable_feedback) {
- CompLevel next_level = cur_level;
- int i = method->invocation_count();
- int b = method->backedge_count();
-
- if (should_compile_at_level_simple(method)) {
- next_level = CompLevel_simple;
- } else {
- switch(cur_level) {
- default: break;
- case CompLevel_aot: {
- // If we were at full profile level, would we switch to full opt?
- if (common(p, method, CompLevel_full_profile, disable_feedback) == CompLevel_full_optimization) {
- next_level = CompLevel_full_optimization;
- } else if (disable_feedback || (CompileBroker::queue_size(CompLevel_full_optimization) <=
- Tier3DelayOff * compiler_count(CompLevel_full_optimization) &&
- (this->*p)(i, b, cur_level, method))) {
- next_level = CompLevel_full_profile;
- }
- }
- break;
- case CompLevel_none:
- // If we were at full profile level, would we switch to full opt?
- if (common(p, method, CompLevel_full_profile, disable_feedback) == CompLevel_full_optimization) {
- next_level = CompLevel_full_optimization;
- } else if ((this->*p)(i, b, cur_level, method)) {
-#if INCLUDE_JVMCI
- if (EnableJVMCI && UseJVMCICompiler) {
- // Since JVMCI takes a while to warm up, its queue inevitably backs up during
- // early VM execution. As of 2014-06-13, JVMCI's inliner assumes that the root
- // compilation method and all potential inlinees have mature profiles (which
- // includes type profiling). If it sees immature profiles, JVMCI's inliner
- // can perform pathologically bad (e.g., causing OutOfMemoryErrors due to
- // exploring/inlining too many graphs). Since a rewrite of the inliner is
- // in progress, we simply disable the dialing back heuristic for now and will
- // revisit this decision once the new inliner is completed.
- next_level = CompLevel_full_profile;
- } else
-#endif
- {
- // C1-generated fully profiled code is about 30% slower than the limited profile
- // code that has only invocation and backedge counters. The observation is that
- // if C2 queue is large enough we can spend too much time in the fully profiled code
- // while waiting for C2 to pick the method from the queue. To alleviate this problem
- // we introduce a feedback on the C2 queue size. If the C2 queue is sufficiently long
- // we choose to compile a limited profiled version and then recompile with full profiling
- // when the load on C2 goes down.
- if (!disable_feedback && CompileBroker::queue_size(CompLevel_full_optimization) >
- Tier3DelayOn * compiler_count(CompLevel_full_optimization)) {
- next_level = CompLevel_limited_profile;
- } else {
- next_level = CompLevel_full_profile;
- }
- }
- }
- break;
- case CompLevel_limited_profile:
- if (is_method_profiled(method)) {
- // Special case: we got here because this method was fully profiled in the interpreter.
- next_level = CompLevel_full_optimization;
- } else {
- MethodData* mdo = method->method_data();
- if (mdo != NULL) {
- if (mdo->would_profile()) {
- if (disable_feedback || (CompileBroker::queue_size(CompLevel_full_optimization) <=
- Tier3DelayOff * compiler_count(CompLevel_full_optimization) &&
- (this->*p)(i, b, cur_level, method))) {
- next_level = CompLevel_full_profile;
- }
- } else {
- next_level = CompLevel_full_optimization;
- }
- } else {
- // If there is no MDO we need to profile
- if (disable_feedback || (CompileBroker::queue_size(CompLevel_full_optimization) <=
- Tier3DelayOff * compiler_count(CompLevel_full_optimization) &&
- (this->*p)(i, b, cur_level, method))) {
- next_level = CompLevel_full_profile;
- }
- }
- }
- break;
- case CompLevel_full_profile:
- {
- MethodData* mdo = method->method_data();
- if (mdo != NULL) {
- if (mdo->would_profile()) {
- int mdo_i = mdo->invocation_count_delta();
- int mdo_b = mdo->backedge_count_delta();
- if ((this->*p)(mdo_i, mdo_b, cur_level, method)) {
- next_level = CompLevel_full_optimization;
- }
- } else {
- next_level = CompLevel_full_optimization;
- }
- }
- }
- break;
- }
- }
- return MIN2(next_level, (CompLevel)TieredStopAtLevel);
-}
-
-// Determine if a method should be compiled with a normal entry point at a different level.
-CompLevel TieredThresholdPolicy::call_event(Method* method, CompLevel cur_level, JavaThread * thread) {
- CompLevel osr_level = MIN2((CompLevel) method->highest_osr_comp_level(),
- common(&TieredThresholdPolicy::loop_predicate, method, cur_level, true));
- CompLevel next_level = common(&TieredThresholdPolicy::call_predicate, method, cur_level);
-
- // If OSR method level is greater than the regular method level, the levels should be
- // equalized by raising the regular method level in order to avoid OSRs during each
- // invocation of the method.
- if (osr_level == CompLevel_full_optimization && cur_level == CompLevel_full_profile) {
- MethodData* mdo = method->method_data();
- guarantee(mdo != NULL, "MDO should not be NULL");
- if (mdo->invocation_count() >= 1) {
- next_level = CompLevel_full_optimization;
- }
- } else {
- next_level = MAX2(osr_level, next_level);
- }
- return next_level;
-}
-
-// Determine if we should do an OSR compilation of a given method.
-CompLevel TieredThresholdPolicy::loop_event(Method* method, CompLevel cur_level, JavaThread* thread) {
- CompLevel next_level = common(&TieredThresholdPolicy::loop_predicate, method, cur_level, true);
- if (cur_level == CompLevel_none) {
- // If there is a live OSR method that means that we deopted to the interpreter
- // for the transition.
- CompLevel osr_level = MIN2((CompLevel)method->highest_osr_comp_level(), next_level);
- if (osr_level > CompLevel_none) {
- return osr_level;
- }
- }
- return next_level;
-}
-
-bool TieredThresholdPolicy::maybe_switch_to_aot(const methodHandle& mh, CompLevel cur_level, CompLevel next_level, JavaThread* thread) {
- if (UseAOT) {
- if (cur_level == CompLevel_full_profile || cur_level == CompLevel_none) {
- // If the current level is full profile or interpreter and we're switching to any other level,
- // activate the AOT code back first so that we won't waste time overprofiling.
- compile(mh, InvocationEntryBci, CompLevel_aot, thread);
- // Fall through for JIT compilation.
- }
- if (next_level == CompLevel_limited_profile && cur_level != CompLevel_aot && mh->has_aot_code()) {
- // If the next level is limited profile, use the aot code (if there is any),
- // since it's essentially the same thing.
- compile(mh, InvocationEntryBci, CompLevel_aot, thread);
- // Not need to JIT, we're done.
- return true;
- }
- }
- return false;
-}
-
-
-// Handle the invocation event.
-void TieredThresholdPolicy::method_invocation_event(const methodHandle& mh, const methodHandle& imh,
- CompLevel level, CompiledMethod* nm, JavaThread* thread) {
- if (should_create_mdo(mh(), level)) {
- create_mdo(mh, thread);
- }
- CompLevel next_level = call_event(mh(), level, thread);
- if (next_level != level) {
- if (maybe_switch_to_aot(mh, level, next_level, thread)) {
- // No JITting necessary
- return;
- }
- if (is_compilation_enabled() && !CompileBroker::compilation_is_in_queue(mh)) {
- compile(mh, InvocationEntryBci, next_level, thread);
- }
- }
-}
-
-// Handle the back branch event. Notice that we can compile the method
-// with a regular entry from here.
-void TieredThresholdPolicy::method_back_branch_event(const methodHandle& mh, const methodHandle& imh,
- int bci, CompLevel level, CompiledMethod* nm, JavaThread* thread) {
- if (should_create_mdo(mh(), level)) {
- create_mdo(mh, thread);
- }
- // Check if MDO should be created for the inlined method
- if (should_create_mdo(imh(), level)) {
- create_mdo(imh, thread);
- }
-
- if (is_compilation_enabled()) {
- CompLevel next_osr_level = loop_event(imh(), level, thread);
- CompLevel max_osr_level = (CompLevel)imh->highest_osr_comp_level();
- // At the very least compile the OSR version
- if (!CompileBroker::compilation_is_in_queue(imh) && (next_osr_level != level)) {
- compile(imh, bci, next_osr_level, thread);
- }
-
- // Use loop event as an opportunity to also check if there's been
- // enough calls.
- CompLevel cur_level, next_level;
- if (mh() != imh()) { // If there is an enclosing method
- if (level == CompLevel_aot) {
- // Recompile the enclosing method to prevent infinite OSRs. Stay at AOT level while it's compiling.
- if (max_osr_level != CompLevel_none && !CompileBroker::compilation_is_in_queue(mh)) {
- compile(mh, InvocationEntryBci, MIN2((CompLevel)TieredStopAtLevel, CompLevel_full_profile), thread);
- }
- } else {
- // Current loop event level is not AOT
- guarantee(nm != NULL, "Should have nmethod here");
- cur_level = comp_level(mh());
- next_level = call_event(mh(), cur_level, thread);
-
- if (max_osr_level == CompLevel_full_optimization) {
- // The inlinee OSRed to full opt, we need to modify the enclosing method to avoid deopts
- bool make_not_entrant = false;
- if (nm->is_osr_method()) {
- // This is an osr method, just make it not entrant and recompile later if needed
- make_not_entrant = true;
- } else {
- if (next_level != CompLevel_full_optimization) {
- // next_level is not full opt, so we need to recompile the
- // enclosing method without the inlinee
- cur_level = CompLevel_none;
- make_not_entrant = true;
- }
- }
- if (make_not_entrant) {
- if (PrintTieredEvents) {
- int osr_bci = nm->is_osr_method() ? nm->osr_entry_bci() : InvocationEntryBci;
- print_event(MAKE_NOT_ENTRANT, mh(), mh(), osr_bci, level);
- }
- nm->make_not_entrant();
- }
- }
- // Fix up next_level if necessary to avoid deopts
- if (next_level == CompLevel_limited_profile && max_osr_level == CompLevel_full_profile) {
- next_level = CompLevel_full_profile;
- }
- if (cur_level != next_level) {
- if (!maybe_switch_to_aot(mh, cur_level, next_level, thread) && !CompileBroker::compilation_is_in_queue(mh)) {
- compile(mh, InvocationEntryBci, next_level, thread);
- }
- }
- }
- } else {
- cur_level = comp_level(mh());
- next_level = call_event(mh(), cur_level, thread);
- if (next_level != cur_level) {
- if (!maybe_switch_to_aot(mh, cur_level, next_level, thread) && !CompileBroker::compilation_is_in_queue(mh)) {
- compile(mh, InvocationEntryBci, next_level, thread);
- }
- }
- }
- }
-}
-
-#endif