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