# HG changeset patch # User redestad # Date 1533853215 -7200 # Node ID f32e61253792a48b0a643302107a1f14e0fceed3 # Parent adcb0bb3d1e95208775eb194f1563a6599f34c2f 8209186: Rename SimpleThresholdPolicy to TieredThresholdPolicy Reviewed-by: thartmann, pliden, kvn diff -r adcb0bb3d1e9 -r f32e61253792 src/hotspot/share/runtime/compilationPolicy.cpp --- a/src/hotspot/share/runtime/compilationPolicy.cpp Thu Aug 09 22:51:48 2018 +0200 +++ b/src/hotspot/share/runtime/compilationPolicy.cpp Fri Aug 10 00:20:15 2018 +0200 @@ -37,9 +37,9 @@ #include "runtime/frame.hpp" #include "runtime/handles.inline.hpp" #include "runtime/rframe.hpp" -#include "runtime/simpleThresholdPolicy.hpp" #include "runtime/stubRoutines.hpp" #include "runtime/thread.hpp" +#include "runtime/tieredThresholdPolicy.hpp" #include "runtime/timer.hpp" #include "runtime/vframe.hpp" #include "runtime/vm_operations.hpp" @@ -68,7 +68,7 @@ break; case 2: #ifdef TIERED - CompilationPolicy::set_policy(new SimpleThresholdPolicy()); + CompilationPolicy::set_policy(new TieredThresholdPolicy()); #else Unimplemented(); #endif diff -r adcb0bb3d1e9 -r f32e61253792 src/hotspot/share/runtime/simpleThresholdPolicy.cpp --- a/src/hotspot/share/runtime/simpleThresholdPolicy.cpp Thu Aug 09 22:51:48 2018 +0200 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,904 +0,0 @@ -/* - * Copyright (c) 2010, 2018, 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 "memory/resourceArea.hpp" -#include "runtime/arguments.hpp" -#include "runtime/handles.inline.hpp" -#include "runtime/safepointVerifiers.hpp" -#include "runtime/simpleThresholdPolicy.hpp" -#include "runtime/simpleThresholdPolicy.inline.hpp" -#include "code/scopeDesc.hpp" -#if INCLUDE_JVMCI -#include "jvmci/jvmciRuntime.hpp" -#endif - -#ifdef TIERED - -void SimpleThresholdPolicy::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 SimpleThresholdPolicy::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 SimpleThresholdPolicy::initialize() { - int count = CICompilerCount; -#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_intptr(os::active_processor_count()); - int loglog_cpu = log2_intptr(MAX2(log_cpu, 1)); - count = MAX2(log_cpu * loglog_cpu * 3 / 2, 2); - FLAG_SET_ERGO(intx, 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(intx, CICompilerCount, count); - } -#endif - - if (TieredStopAtLevel < CompLevel_full_optimization) { - // 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 SimpleThresholdPolicy::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 SimpleThresholdPolicy::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* SimpleThresholdPolicy::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(); - update_rate(t, method); - if (max_task == NULL) { - max_task = task; - max_method = method; - } else { - // If a method 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->can_become_stale() && is_stale(t, TieredCompileTaskTimeout, method) && !is_old(method)) { - if (PrintTieredEvents) { - print_event(REMOVE_FROM_QUEUE, method, method, task->osr_bci(), (CompLevel)task->comp_level()); - } - compile_queue->remove_and_mark_stale(task); - method->clear_queued_for_compilation(); - task = next_task; - continue; - } - - // Select a method with a higher rate - if (compare_methods(method, max_method)) { - 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 (PrintTieredEvents) { - print_event(UPDATE_IN_QUEUE, max_method, max_method, max_task->osr_bci(), (CompLevel)max_task->comp_level()); - } - } - - return max_task; -} - -void SimpleThresholdPolicy::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* SimpleThresholdPolicy::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 (CompileTheWorld || 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 - nmethod* osr_nm = inlinee->lookup_osr_nmethod_for(bci, comp_level, false); - if (osr_nm != NULL && osr_nm->comp_level() > comp_level) { - // Perform OSR with new nmethod - return osr_nm; - } - } - return NULL; -} - -// Check if the method can be compiled, change level if necessary -void SimpleThresholdPolicy::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(); - } - 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 (!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 && 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 SimpleThresholdPolicy::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 SimpleThresholdPolicy::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 SimpleThresholdPolicy::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 - SafepointSynchronize::end_of_last_safepoint(); - 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 from a given number of milliseconds. -// See select_task(). -bool SimpleThresholdPolicy::is_stale(jlong t, jlong timeout, Method* m) { - jlong delta_s = t - SafepointSynchronize::end_of_last_safepoint(); - 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 SimpleThresholdPolicy::is_old(Method* method) { - return method->invocation_count() > 50000 || method->backedge_count() > 500000; -} - -double SimpleThresholdPolicy::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 SimpleThresholdPolicy::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 SimpleThresholdPolicy::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(i, b, 1, method); - } - return false; -} - -double SimpleThresholdPolicy::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 SimpleThresholdPolicy::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(i, b, k, method); - } - case CompLevel_none: - case CompLevel_limited_profile: { - double k = threshold_scale(CompLevel_full_profile, Tier3LoadFeedback); - return loop_predicate_helper(i, b, k, method); - } - case CompLevel_full_profile: { - double k = threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback); - return loop_predicate_helper(i, b, k, method); - } - default: - return true; - } -} - -bool SimpleThresholdPolicy::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(i, b, k, method); - } - case CompLevel_none: - case CompLevel_limited_profile: { - double k = threshold_scale(CompLevel_full_profile, Tier3LoadFeedback); - return call_predicate_helper(i, b, k, method); - } - case CompLevel_full_profile: { - double k = threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback); - return call_predicate_helper(i, b, k, method); - } - default: - return true; - } -} - -// Determine is a method is mature. -bool SimpleThresholdPolicy::is_mature(Method* method) { - if (is_trivial(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(i, b, k, method) || - loop_predicate_helper(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 SimpleThresholdPolicy::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(i, b, k, method) || loop_predicate_helper(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 SimpleThresholdPolicy::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 SimpleThresholdPolicy::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 SimpleThresholdPolicy::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 (is_trivial(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 SimpleThresholdPolicy::call_event(Method* method, CompLevel cur_level, JavaThread * thread) { - CompLevel osr_level = MIN2((CompLevel) method->highest_osr_comp_level(), - common(&SimpleThresholdPolicy::loop_predicate, method, cur_level, true)); - CompLevel next_level = common(&SimpleThresholdPolicy::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); - } -#if INCLUDE_JVMCI - if (UseJVMCICompiler) { - next_level = JVMCIRuntime::adjust_comp_level(method, false, next_level, thread); - } -#endif - return next_level; -} - -// Determine if we should do an OSR compilation of a given method. -CompLevel SimpleThresholdPolicy::loop_event(Method* method, CompLevel cur_level, JavaThread* thread) { - CompLevel next_level = common(&SimpleThresholdPolicy::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; - } - } -#if INCLUDE_JVMCI - if (UseJVMCICompiler) { - next_level = JVMCIRuntime::adjust_comp_level(method, true, next_level, thread); - } -#endif - return next_level; -} - -bool SimpleThresholdPolicy::maybe_switch_to_aot(const methodHandle& mh, CompLevel cur_level, CompLevel next_level, JavaThread* thread) { - if (UseAOT && !delay_compilation_during_startup()) { - 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 SimpleThresholdPolicy::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 SimpleThresholdPolicy::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 diff -r adcb0bb3d1e9 -r f32e61253792 src/hotspot/share/runtime/simpleThresholdPolicy.hpp --- a/src/hotspot/share/runtime/simpleThresholdPolicy.hpp Thu Aug 09 22:51:48 2018 +0200 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,277 +0,0 @@ -/* - * Copyright (c) 2010, 2018, 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. - * - */ - -#ifndef SHARE_VM_RUNTIME_SIMPLETHRESHOLDPOLICY_HPP -#define SHARE_VM_RUNTIME_SIMPLETHRESHOLDPOLICY_HPP - -#include "code/nmethod.hpp" -#include "oops/methodData.hpp" -#include "runtime/compilationPolicy.hpp" -#include "utilities/globalDefinitions.hpp" - -#ifdef TIERED - -class CompileTask; -class CompileQueue; -/* - * The system supports 5 execution levels: - * * level 0 - interpreter - * * level 1 - C1 with full optimization (no profiling) - * * level 2 - C1 with invocation and backedge counters - * * level 3 - C1 with full profiling (level 2 + MDO) - * * level 4 - C2 - * - * Levels 0, 2 and 3 periodically notify the runtime about the current value of the counters - * (invocation counters and backedge counters). The frequency of these notifications is - * different at each level. These notifications are used by the policy to decide what transition - * to make. - * - * Execution starts at level 0 (interpreter), then the policy can decide either to compile the - * method at level 3 or level 2. The decision is based on the following factors: - * 1. The length of the C2 queue determines the next level. The observation is that level 2 - * is generally faster than level 3 by about 30%, therefore we would want to minimize the time - * a method spends at level 3. We should only spend the time at level 3 that is necessary to get - * adequate profiling. So, if the C2 queue is long enough it is more beneficial to go first to - * level 2, because if we transitioned to level 3 we would be stuck there until our C2 compile - * request makes its way through the long queue. When the load on C2 recedes we are going to - * recompile at level 3 and start gathering profiling information. - * 2. The length of C1 queue is used to dynamically adjust the thresholds, so as to introduce - * additional filtering if the compiler is overloaded. The rationale is that by the time a - * method gets compiled it can become unused, so it doesn't make sense to put too much onto the - * queue. - * - * After profiling is completed at level 3 the transition is made to level 4. Again, the length - * of the C2 queue is used as a feedback to adjust the thresholds. - * - * After the first C1 compile some basic information is determined about the code like the number - * of the blocks and the number of the loops. Based on that it can be decided that a method - * is trivial and compiling it with C1 will yield the same code. In this case the method is - * compiled at level 1 instead of 4. - * - * We also support profiling at level 0. If C1 is slow enough to produce the level 3 version of - * the code and the C2 queue is sufficiently small we can decide to start profiling in the - * interpreter (and continue profiling in the compiled code once the level 3 version arrives). - * If the profiling at level 0 is fully completed before level 3 version is produced, a level 2 - * version is compiled instead in order to run faster waiting for a level 4 version. - * - * Compile queues are implemented as priority queues - for each method in the queue we compute - * the event rate (the number of invocation and backedge counter increments per unit of time). - * When getting an element off the queue we pick the one with the largest rate. Maintaining the - * rate also allows us to remove stale methods (the ones that got on the queue but stopped - * being used shortly after that). -*/ - -/* Command line options: - * - Tier?InvokeNotifyFreqLog and Tier?BackedgeNotifyFreqLog control the frequency of method - * invocation and backedge notifications. Basically every n-th invocation or backedge a mutator thread - * makes a call into the runtime. - * - * - Tier?InvocationThreshold, Tier?CompileThreshold, Tier?BackEdgeThreshold, Tier?MinInvocationThreshold control - * compilation thresholds. - * Level 2 thresholds are not used and are provided for option-compatibility and potential future use. - * Other thresholds work as follows: - * - * Transition from interpreter (level 0) to C1 with full profiling (level 3) happens when - * the following predicate is true (X is the level): - * - * i > TierXInvocationThreshold * s || (i > TierXMinInvocationThreshold * s && i + b > TierXCompileThreshold * s), - * - * where $i$ is the number of method invocations, $b$ number of backedges and $s$ is the scaling - * coefficient that will be discussed further. - * The intuition is to equalize the time that is spend profiling each method. - * The same predicate is used to control the transition from level 3 to level 4 (C2). It should be - * noted though that the thresholds are relative. Moreover i and b for the 0->3 transition come - * from Method* and for 3->4 transition they come from MDO (since profiled invocations are - * counted separately). Finally, if a method does not contain anything worth profiling, a transition - * from level 3 to level 4 occurs without considering thresholds (e.g., with fewer invocations than - * what is specified by Tier4InvocationThreshold). - * - * OSR transitions are controlled simply with b > TierXBackEdgeThreshold * s predicates. - * - * - Tier?LoadFeedback options are used to automatically scale the predicates described above depending - * on the compiler load. The scaling coefficients are computed as follows: - * - * s = queue_size_X / (TierXLoadFeedback * compiler_count_X) + 1, - * - * where queue_size_X is the current size of the compiler queue of level X, and compiler_count_X - * is the number of level X compiler threads. - * - * Basically these parameters describe how many methods should be in the compile queue - * per compiler thread before the scaling coefficient increases by one. - * - * This feedback provides the mechanism to automatically control the flow of compilation requests - * depending on the machine speed, mutator load and other external factors. - * - * - Tier3DelayOn and Tier3DelayOff parameters control another important feedback loop. - * Consider the following observation: a method compiled with full profiling (level 3) - * is about 30% slower than a method at level 2 (just invocation and backedge counters, no MDO). - * Normally, the following transitions will occur: 0->3->4. The problem arises when the C2 queue - * gets congested and the 3->4 transition is delayed. While the method is the C2 queue it continues - * executing at level 3 for much longer time than is required by the predicate and at suboptimal speed. - * The idea is to dynamically change the behavior of the system in such a way that if a substantial - * load on C2 is detected we would first do the 0->2 transition allowing a method to run faster. - * And then when the load decreases to allow 2->3 transitions. - * - * Tier3Delay* parameters control this switching mechanism. - * Tier3DelayOn is the number of methods in the C2 queue per compiler thread after which the policy - * no longer does 0->3 transitions but does 0->2 transitions instead. - * Tier3DelayOff switches the original behavior back when the number of methods in the C2 queue - * per compiler thread falls below the specified amount. - * The hysteresis is necessary to avoid jitter. - * - * - TieredCompileTaskTimeout is the amount of time an idle method can spend in the compile queue. - * Basically, since we use the event rate d(i + b)/dt as a value of priority when selecting a method to - * compile from the compile queue, we also can detect stale methods for which the rate has been - * 0 for some time in the same iteration. Stale methods can appear in the queue when an application - * abruptly changes its behavior. - * - * - TieredStopAtLevel, is used mostly for testing. It allows to bypass the policy logic and stick - * to a given level. For example it's useful to set TieredStopAtLevel = 1 in order to compile everything - * with pure c1. - * - * - Tier0ProfilingStartPercentage allows the interpreter to start profiling when the inequalities in the - * 0->3 predicate are already exceeded by the given percentage but the level 3 version of the - * method is still not ready. We can even go directly from level 0 to 4 if c1 doesn't produce a compiled - * version in time. This reduces the overall transition to level 4 and decreases the startup time. - * Note that this behavior is also guarded by the Tier3Delay mechanism: when the c2 queue is too long - * these is not reason to start profiling prematurely. - * - * - TieredRateUpdateMinTime and TieredRateUpdateMaxTime are parameters of the rate computation. - * Basically, the rate is not computed more frequently than TieredRateUpdateMinTime and is considered - * to be zero if no events occurred in TieredRateUpdateMaxTime. - */ - -class SimpleThresholdPolicy : public CompilationPolicy { - jlong _start_time; - int _c1_count, _c2_count; - - // Check if the counter is big enough and set carry (effectively infinity). - inline void set_carry_if_necessary(InvocationCounter *counter); - // Set carry flags in the counters (in Method* and MDO). - inline void handle_counter_overflow(Method* method); - // Call and loop predicates determine whether a transition to a higher compilation - // level should be performed (pointers to predicate functions are passed to common_TF(). - // Predicates also take compiler load into account. - typedef bool (SimpleThresholdPolicy::*Predicate)(int i, int b, CompLevel cur_level, Method* method); - bool call_predicate(int i, int b, CompLevel cur_level, Method* method); - bool loop_predicate(int i, int b, CompLevel cur_level, Method* method); - // Common transition function. Given a predicate determines if a method should transition to another level. - CompLevel common(Predicate p, Method* method, CompLevel cur_level, bool disable_feedback = false); - // Transition functions. - // call_event determines if a method should be compiled at a different - // level with a regular invocation entry. - CompLevel call_event(Method* method, CompLevel cur_level, JavaThread* thread); - // loop_event checks if a method should be OSR compiled at a different - // level. - CompLevel loop_event(Method* method, CompLevel cur_level, JavaThread* thread); - void print_counters(const char* prefix, const methodHandle& mh); - // Has a method been long around? - // We don't remove old methods from the compile queue even if they have - // very low activity (see select_task()). - inline bool is_old(Method* method); - // Was a given method inactive for a given number of milliseconds. - // If it is, we would remove it from the queue (see select_task()). - inline bool is_stale(jlong t, jlong timeout, Method* m); - // Compute the weight of the method for the compilation scheduling - inline double weight(Method* method); - // Apply heuristics and return true if x should be compiled before y - inline bool compare_methods(Method* x, Method* y); - // Compute event rate for a given method. The rate is the number of event (invocations + backedges) - // per millisecond. - inline void update_rate(jlong t, Method* m); - // Compute threshold scaling coefficient - inline double threshold_scale(CompLevel level, int feedback_k); - // 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. This function - // determines whether we should do that. - inline bool should_create_mdo(Method* method, CompLevel cur_level); - // Create MDO if necessary. - void create_mdo(const methodHandle& mh, JavaThread* thread); - // Is method profiled enough? - bool is_method_profiled(Method* method); - - double _increase_threshold_at_ratio; - - bool maybe_switch_to_aot(const methodHandle& mh, CompLevel cur_level, CompLevel next_level, JavaThread* thread); - -protected: - int c1_count() const { return _c1_count; } - int c2_count() const { return _c2_count; } - void set_c1_count(int x) { _c1_count = x; } - void set_c2_count(int x) { _c2_count = x; } - - enum EventType { CALL, LOOP, COMPILE, REMOVE_FROM_QUEUE, UPDATE_IN_QUEUE, REPROFILE, MAKE_NOT_ENTRANT }; - void print_event(EventType type, const methodHandle& mh, const methodHandle& imh, int bci, CompLevel level); - // Print policy-specific information if necessary - virtual void print_specific(EventType type, const methodHandle& mh, const methodHandle& imh, int bci, CompLevel level); - // Check if the method can be compiled, change level if necessary - void compile(const methodHandle& mh, int bci, CompLevel level, JavaThread* thread); - // Submit a given method for compilation - virtual void submit_compile(const methodHandle& mh, int bci, CompLevel level, JavaThread* thread); - // Simple methods are as good being compiled with C1 as C2. - // This function tells if it's such a function. - inline bool is_trivial(Method* method); - - // Predicate helpers are used by .*_predicate() methods as well as others. - // They check the given counter values, multiplied by the scale against the thresholds. - template static inline bool call_predicate_helper(int i, int b, double scale, Method* method); - template static inline bool loop_predicate_helper(int i, int b, double scale, Method* method); - - // Get a compilation level for a given method. - static CompLevel comp_level(Method* method); - virtual void method_invocation_event(const methodHandle& method, const methodHandle& inlinee, - CompLevel level, CompiledMethod* nm, JavaThread* thread); - virtual void method_back_branch_event(const methodHandle& method, const methodHandle& inlinee, - int bci, CompLevel level, CompiledMethod* nm, JavaThread* thread); - - void set_increase_threshold_at_ratio() { _increase_threshold_at_ratio = 100 / (100 - (double)IncreaseFirstTierCompileThresholdAt); } - void set_start_time(jlong t) { _start_time = t; } - jlong start_time() const { return _start_time; } - -public: - SimpleThresholdPolicy() : _start_time(0), _c1_count(0), _c2_count(0) { } - virtual int compiler_count(CompLevel comp_level) { - if (is_c1_compile(comp_level)) return c1_count(); - if (is_c2_compile(comp_level)) return c2_count(); - return 0; - } - virtual CompLevel initial_compile_level() { return MIN2((CompLevel)TieredStopAtLevel, CompLevel_initial_compile); } - virtual void do_safepoint_work() { } - virtual void delay_compilation(Method* method) { } - virtual void disable_compilation(Method* method) { } - virtual void reprofile(ScopeDesc* trap_scope, bool is_osr); - virtual nmethod* event(const methodHandle& method, const methodHandle& inlinee, - int branch_bci, int bci, CompLevel comp_level, CompiledMethod* nm, JavaThread* thread); - // Select task is called by CompileBroker. We should return a task or NULL. - virtual CompileTask* select_task(CompileQueue* compile_queue); - // Tell the runtime if we think a given method is adequately profiled. - virtual bool is_mature(Method* method); - // Initialize: set compiler thread count - virtual void initialize(); - virtual bool should_not_inline(ciEnv* env, ciMethod* callee); -}; - -#endif // TIERED - -#endif // SHARE_VM_RUNTIME_SIMPLETHRESHOLDPOLICY_HPP diff -r adcb0bb3d1e9 -r f32e61253792 src/hotspot/share/runtime/simpleThresholdPolicy.inline.hpp --- a/src/hotspot/share/runtime/simpleThresholdPolicy.inline.hpp Thu Aug 09 22:51:48 2018 +0200 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,108 +0,0 @@ -/* - * Copyright (c) 2001, 2018, 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. - * - */ - -#ifndef SHARE_VM_RUNTIME_SIMPLETHRESHOLDPOLICY_INLINE_HPP -#define SHARE_VM_RUNTIME_SIMPLETHRESHOLDPOLICY_INLINE_HPP - -#include "compiler/compilerOracle.hpp" -#include "oops/method.inline.hpp" - -#ifdef TIERED - -template -bool SimpleThresholdPolicy::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 -bool SimpleThresholdPolicy::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 SimpleThresholdPolicy::is_trivial(Method* method) { - if (method->is_accessor() || - method->is_constant_getter()) { - return true; - } -#if INCLUDE_JVMCI - if (UseJVMCICompiler) { - AbstractCompiler* comp = CompileBroker::compiler(CompLevel_full_optimization); - if (TieredCompilation && comp != NULL && comp->is_trivial(method)) { - return true; - } - } -#endif - if (method->has_loops() || method->code_size() >= 15) { - return false; - } - MethodData* mdo = method->method_data(); - if (mdo != NULL && !mdo->would_profile() && - (method->code_size() < 5 || (mdo->num_blocks() < 4))) { - return true; - } - return false; -} - -inline CompLevel SimpleThresholdPolicy::comp_level(Method* method) { - CompiledMethod *nm = method->code(); - if (nm != NULL && nm->is_in_use()) { - return (CompLevel)nm->comp_level(); - } - return CompLevel_none; -} - -#endif // TIERED - -#endif // SHARE_VM_RUNTIME_SIMPLETHRESHOLDPOLICY_INLINE_HPP diff -r adcb0bb3d1e9 -r f32e61253792 src/hotspot/share/runtime/tieredThresholdPolicy.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/hotspot/share/runtime/tieredThresholdPolicy.cpp Fri Aug 10 00:20:15 2018 +0200 @@ -0,0 +1,978 @@ +/* + * Copyright (c) 2010, 2018, 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/safepointVerifiers.hpp" +#include "runtime/tieredThresholdPolicy.hpp" +#include "code/scopeDesc.hpp" +#include "oops/method.inline.hpp" +#if INCLUDE_JVMCI +#include "jvmci/jvmciRuntime.hpp" +#endif + +#ifdef TIERED + +template +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 +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; + } +#if INCLUDE_JVMCI + if (UseJVMCICompiler) { + AbstractCompiler* comp = CompileBroker::compiler(CompLevel_full_optimization); + if (TieredCompilation && comp != NULL && comp->is_trivial(method)) { + return true; + } + } +#endif + if (method->has_loops() || method->code_size() >= 15) { + return false; + } + MethodData* mdo = method->method_data(); + if (mdo != NULL && !mdo->would_profile() && + (method->code_size() < 5 || (mdo->num_blocks() < 4))) { + return true; + } + 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; +#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_intptr(os::active_processor_count()); + int loglog_cpu = log2_intptr(MAX2(log_cpu, 1)); + count = MAX2(log_cpu * loglog_cpu * 3 / 2, 2); + FLAG_SET_ERGO(intx, 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(intx, CICompilerCount, count); + } +#endif + + if (TieredStopAtLevel < CompLevel_full_optimization) { + // 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(); + update_rate(t, method); + if (max_task == NULL) { + max_task = task; + max_method = method; + } else { + // If a method 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->can_become_stale() && is_stale(t, TieredCompileTaskTimeout, method) && !is_old(method)) { + if (PrintTieredEvents) { + print_event(REMOVE_FROM_QUEUE, method, method, task->osr_bci(), (CompLevel)task->comp_level()); + } + compile_queue->remove_and_mark_stale(task); + method->clear_queued_for_compilation(); + task = next_task; + continue; + } + + // Select a method with a higher rate + if (compare_methods(method, max_method)) { + 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 (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 (CompileTheWorld || 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 + nmethod* osr_nm = inlinee->lookup_osr_nmethod_for(bci, comp_level, false); + if (osr_nm != NULL && osr_nm->comp_level() > comp_level) { + // 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(); + } + 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 (!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 && 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 - SafepointSynchronize::end_of_last_safepoint(); + 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 from a given number of milliseconds. +// See select_task(). +bool TieredThresholdPolicy::is_stale(jlong t, jlong timeout, Method* m) { + jlong delta_s = t - SafepointSynchronize::end_of_last_safepoint(); + 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(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(i, b, k, method); + } + case CompLevel_none: + case CompLevel_limited_profile: { + double k = threshold_scale(CompLevel_full_profile, Tier3LoadFeedback); + return loop_predicate_helper(i, b, k, method); + } + case CompLevel_full_profile: { + double k = threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback); + return loop_predicate_helper(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(i, b, k, method); + } + case CompLevel_none: + case CompLevel_limited_profile: { + double k = threshold_scale(CompLevel_full_profile, Tier3LoadFeedback); + return call_predicate_helper(i, b, k, method); + } + case CompLevel_full_profile: { + double k = threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback); + return call_predicate_helper(i, b, k, method); + } + default: + return true; + } +} + +// Determine is a method is mature. +bool TieredThresholdPolicy::is_mature(Method* method) { + if (is_trivial(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(i, b, k, method) || + loop_predicate_helper(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(i, b, k, method) || loop_predicate_helper(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 (is_trivial(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); + } +#if INCLUDE_JVMCI + if (UseJVMCICompiler) { + next_level = JVMCIRuntime::adjust_comp_level(method, false, next_level, thread); + } +#endif + 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; + } + } +#if INCLUDE_JVMCI + if (UseJVMCICompiler) { + next_level = JVMCIRuntime::adjust_comp_level(method, true, next_level, thread); + } +#endif + return next_level; +} + +bool TieredThresholdPolicy::maybe_switch_to_aot(const methodHandle& mh, CompLevel cur_level, CompLevel next_level, JavaThread* thread) { + if (UseAOT && !delay_compilation_during_startup()) { + 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 diff -r adcb0bb3d1e9 -r f32e61253792 src/hotspot/share/runtime/tieredThresholdPolicy.hpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/hotspot/share/runtime/tieredThresholdPolicy.hpp Fri Aug 10 00:20:15 2018 +0200 @@ -0,0 +1,277 @@ +/* + * Copyright (c) 2010, 2018, 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. + * + */ + +#ifndef SHARE_VM_RUNTIME_TIEREDTHRESHOLDPOLICY_HPP +#define SHARE_VM_RUNTIME_TIEREDTHRESHOLDPOLICY_HPP + +#include "code/nmethod.hpp" +#include "oops/methodData.hpp" +#include "runtime/compilationPolicy.hpp" +#include "utilities/globalDefinitions.hpp" + +#ifdef TIERED + +class CompileTask; +class CompileQueue; +/* + * The system supports 5 execution levels: + * * level 0 - interpreter + * * level 1 - C1 with full optimization (no profiling) + * * level 2 - C1 with invocation and backedge counters + * * level 3 - C1 with full profiling (level 2 + MDO) + * * level 4 - C2 + * + * Levels 0, 2 and 3 periodically notify the runtime about the current value of the counters + * (invocation counters and backedge counters). The frequency of these notifications is + * different at each level. These notifications are used by the policy to decide what transition + * to make. + * + * Execution starts at level 0 (interpreter), then the policy can decide either to compile the + * method at level 3 or level 2. The decision is based on the following factors: + * 1. The length of the C2 queue determines the next level. The observation is that level 2 + * is generally faster than level 3 by about 30%, therefore we would want to minimize the time + * a method spends at level 3. We should only spend the time at level 3 that is necessary to get + * adequate profiling. So, if the C2 queue is long enough it is more beneficial to go first to + * level 2, because if we transitioned to level 3 we would be stuck there until our C2 compile + * request makes its way through the long queue. When the load on C2 recedes we are going to + * recompile at level 3 and start gathering profiling information. + * 2. The length of C1 queue is used to dynamically adjust the thresholds, so as to introduce + * additional filtering if the compiler is overloaded. The rationale is that by the time a + * method gets compiled it can become unused, so it doesn't make sense to put too much onto the + * queue. + * + * After profiling is completed at level 3 the transition is made to level 4. Again, the length + * of the C2 queue is used as a feedback to adjust the thresholds. + * + * After the first C1 compile some basic information is determined about the code like the number + * of the blocks and the number of the loops. Based on that it can be decided that a method + * is trivial and compiling it with C1 will yield the same code. In this case the method is + * compiled at level 1 instead of 4. + * + * We also support profiling at level 0. If C1 is slow enough to produce the level 3 version of + * the code and the C2 queue is sufficiently small we can decide to start profiling in the + * interpreter (and continue profiling in the compiled code once the level 3 version arrives). + * If the profiling at level 0 is fully completed before level 3 version is produced, a level 2 + * version is compiled instead in order to run faster waiting for a level 4 version. + * + * Compile queues are implemented as priority queues - for each method in the queue we compute + * the event rate (the number of invocation and backedge counter increments per unit of time). + * When getting an element off the queue we pick the one with the largest rate. Maintaining the + * rate also allows us to remove stale methods (the ones that got on the queue but stopped + * being used shortly after that). +*/ + +/* Command line options: + * - Tier?InvokeNotifyFreqLog and Tier?BackedgeNotifyFreqLog control the frequency of method + * invocation and backedge notifications. Basically every n-th invocation or backedge a mutator thread + * makes a call into the runtime. + * + * - Tier?InvocationThreshold, Tier?CompileThreshold, Tier?BackEdgeThreshold, Tier?MinInvocationThreshold control + * compilation thresholds. + * Level 2 thresholds are not used and are provided for option-compatibility and potential future use. + * Other thresholds work as follows: + * + * Transition from interpreter (level 0) to C1 with full profiling (level 3) happens when + * the following predicate is true (X is the level): + * + * i > TierXInvocationThreshold * s || (i > TierXMinInvocationThreshold * s && i + b > TierXCompileThreshold * s), + * + * where $i$ is the number of method invocations, $b$ number of backedges and $s$ is the scaling + * coefficient that will be discussed further. + * The intuition is to equalize the time that is spend profiling each method. + * The same predicate is used to control the transition from level 3 to level 4 (C2). It should be + * noted though that the thresholds are relative. Moreover i and b for the 0->3 transition come + * from Method* and for 3->4 transition they come from MDO (since profiled invocations are + * counted separately). Finally, if a method does not contain anything worth profiling, a transition + * from level 3 to level 4 occurs without considering thresholds (e.g., with fewer invocations than + * what is specified by Tier4InvocationThreshold). + * + * OSR transitions are controlled simply with b > TierXBackEdgeThreshold * s predicates. + * + * - Tier?LoadFeedback options are used to automatically scale the predicates described above depending + * on the compiler load. The scaling coefficients are computed as follows: + * + * s = queue_size_X / (TierXLoadFeedback * compiler_count_X) + 1, + * + * where queue_size_X is the current size of the compiler queue of level X, and compiler_count_X + * is the number of level X compiler threads. + * + * Basically these parameters describe how many methods should be in the compile queue + * per compiler thread before the scaling coefficient increases by one. + * + * This feedback provides the mechanism to automatically control the flow of compilation requests + * depending on the machine speed, mutator load and other external factors. + * + * - Tier3DelayOn and Tier3DelayOff parameters control another important feedback loop. + * Consider the following observation: a method compiled with full profiling (level 3) + * is about 30% slower than a method at level 2 (just invocation and backedge counters, no MDO). + * Normally, the following transitions will occur: 0->3->4. The problem arises when the C2 queue + * gets congested and the 3->4 transition is delayed. While the method is the C2 queue it continues + * executing at level 3 for much longer time than is required by the predicate and at suboptimal speed. + * The idea is to dynamically change the behavior of the system in such a way that if a substantial + * load on C2 is detected we would first do the 0->2 transition allowing a method to run faster. + * And then when the load decreases to allow 2->3 transitions. + * + * Tier3Delay* parameters control this switching mechanism. + * Tier3DelayOn is the number of methods in the C2 queue per compiler thread after which the policy + * no longer does 0->3 transitions but does 0->2 transitions instead. + * Tier3DelayOff switches the original behavior back when the number of methods in the C2 queue + * per compiler thread falls below the specified amount. + * The hysteresis is necessary to avoid jitter. + * + * - TieredCompileTaskTimeout is the amount of time an idle method can spend in the compile queue. + * Basically, since we use the event rate d(i + b)/dt as a value of priority when selecting a method to + * compile from the compile queue, we also can detect stale methods for which the rate has been + * 0 for some time in the same iteration. Stale methods can appear in the queue when an application + * abruptly changes its behavior. + * + * - TieredStopAtLevel, is used mostly for testing. It allows to bypass the policy logic and stick + * to a given level. For example it's useful to set TieredStopAtLevel = 1 in order to compile everything + * with pure c1. + * + * - Tier0ProfilingStartPercentage allows the interpreter to start profiling when the inequalities in the + * 0->3 predicate are already exceeded by the given percentage but the level 3 version of the + * method is still not ready. We can even go directly from level 0 to 4 if c1 doesn't produce a compiled + * version in time. This reduces the overall transition to level 4 and decreases the startup time. + * Note that this behavior is also guarded by the Tier3Delay mechanism: when the c2 queue is too long + * these is not reason to start profiling prematurely. + * + * - TieredRateUpdateMinTime and TieredRateUpdateMaxTime are parameters of the rate computation. + * Basically, the rate is not computed more frequently than TieredRateUpdateMinTime and is considered + * to be zero if no events occurred in TieredRateUpdateMaxTime. + */ + +class TieredThresholdPolicy : public CompilationPolicy { + jlong _start_time; + int _c1_count, _c2_count; + + // Check if the counter is big enough and set carry (effectively infinity). + inline void set_carry_if_necessary(InvocationCounter *counter); + // Set carry flags in the counters (in Method* and MDO). + inline void handle_counter_overflow(Method* method); + // Call and loop predicates determine whether a transition to a higher compilation + // level should be performed (pointers to predicate functions are passed to common_TF(). + // Predicates also take compiler load into account. + typedef bool (TieredThresholdPolicy::*Predicate)(int i, int b, CompLevel cur_level, Method* method); + bool call_predicate(int i, int b, CompLevel cur_level, Method* method); + bool loop_predicate(int i, int b, CompLevel cur_level, Method* method); + // Common transition function. Given a predicate determines if a method should transition to another level. + CompLevel common(Predicate p, Method* method, CompLevel cur_level, bool disable_feedback = false); + // Transition functions. + // call_event determines if a method should be compiled at a different + // level with a regular invocation entry. + CompLevel call_event(Method* method, CompLevel cur_level, JavaThread* thread); + // loop_event checks if a method should be OSR compiled at a different + // level. + CompLevel loop_event(Method* method, CompLevel cur_level, JavaThread* thread); + void print_counters(const char* prefix, const methodHandle& mh); + // Has a method been long around? + // We don't remove old methods from the compile queue even if they have + // very low activity (see select_task()). + inline bool is_old(Method* method); + // Was a given method inactive for a given number of milliseconds. + // If it is, we would remove it from the queue (see select_task()). + inline bool is_stale(jlong t, jlong timeout, Method* m); + // Compute the weight of the method for the compilation scheduling + inline double weight(Method* method); + // Apply heuristics and return true if x should be compiled before y + inline bool compare_methods(Method* x, Method* y); + // Compute event rate for a given method. The rate is the number of event (invocations + backedges) + // per millisecond. + inline void update_rate(jlong t, Method* m); + // Compute threshold scaling coefficient + inline double threshold_scale(CompLevel level, int feedback_k); + // 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. This function + // determines whether we should do that. + inline bool should_create_mdo(Method* method, CompLevel cur_level); + // Create MDO if necessary. + void create_mdo(const methodHandle& mh, JavaThread* thread); + // Is method profiled enough? + bool is_method_profiled(Method* method); + + double _increase_threshold_at_ratio; + + bool maybe_switch_to_aot(const methodHandle& mh, CompLevel cur_level, CompLevel next_level, JavaThread* thread); + +protected: + int c1_count() const { return _c1_count; } + int c2_count() const { return _c2_count; } + void set_c1_count(int x) { _c1_count = x; } + void set_c2_count(int x) { _c2_count = x; } + + enum EventType { CALL, LOOP, COMPILE, REMOVE_FROM_QUEUE, UPDATE_IN_QUEUE, REPROFILE, MAKE_NOT_ENTRANT }; + void print_event(EventType type, const methodHandle& mh, const methodHandle& imh, int bci, CompLevel level); + // Print policy-specific information if necessary + virtual void print_specific(EventType type, const methodHandle& mh, const methodHandle& imh, int bci, CompLevel level); + // Check if the method can be compiled, change level if necessary + void compile(const methodHandle& mh, int bci, CompLevel level, JavaThread* thread); + // Submit a given method for compilation + virtual void submit_compile(const methodHandle& mh, int bci, CompLevel level, JavaThread* thread); + // Simple methods are as good being compiled with C1 as C2. + // This function tells if it's such a function. + inline bool is_trivial(Method* method); + + // Predicate helpers are used by .*_predicate() methods as well as others. + // They check the given counter values, multiplied by the scale against the thresholds. + template static inline bool call_predicate_helper(int i, int b, double scale, Method* method); + template static inline bool loop_predicate_helper(int i, int b, double scale, Method* method); + + // Get a compilation level for a given method. + static CompLevel comp_level(Method* method); + virtual void method_invocation_event(const methodHandle& method, const methodHandle& inlinee, + CompLevel level, CompiledMethod* nm, JavaThread* thread); + virtual void method_back_branch_event(const methodHandle& method, const methodHandle& inlinee, + int bci, CompLevel level, CompiledMethod* nm, JavaThread* thread); + + void set_increase_threshold_at_ratio() { _increase_threshold_at_ratio = 100 / (100 - (double)IncreaseFirstTierCompileThresholdAt); } + void set_start_time(jlong t) { _start_time = t; } + jlong start_time() const { return _start_time; } + +public: + TieredThresholdPolicy() : _start_time(0), _c1_count(0), _c2_count(0) { } + virtual int compiler_count(CompLevel comp_level) { + if (is_c1_compile(comp_level)) return c1_count(); + if (is_c2_compile(comp_level)) return c2_count(); + return 0; + } + virtual CompLevel initial_compile_level() { return MIN2((CompLevel)TieredStopAtLevel, CompLevel_initial_compile); } + virtual void do_safepoint_work() { } + virtual void delay_compilation(Method* method) { } + virtual void disable_compilation(Method* method) { } + virtual void reprofile(ScopeDesc* trap_scope, bool is_osr); + virtual nmethod* event(const methodHandle& method, const methodHandle& inlinee, + int branch_bci, int bci, CompLevel comp_level, CompiledMethod* nm, JavaThread* thread); + // Select task is called by CompileBroker. We should return a task or NULL. + virtual CompileTask* select_task(CompileQueue* compile_queue); + // Tell the runtime if we think a given method is adequately profiled. + virtual bool is_mature(Method* method); + // Initialize: set compiler thread count + virtual void initialize(); + virtual bool should_not_inline(ciEnv* env, ciMethod* callee); +}; + +#endif // TIERED + +#endif // SHARE_VM_RUNTIME_TIEREDTHRESHOLDPOLICY_HPP