jdk8-mips64-public/hotspot: comparison src/share/vm/runtime/advancedThresholdPolicy.cpp

--1:000000000000
+:f90c822e73f8
+/*
+* Copyright (c) 2010, 2013, 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 "runtime/advancedThresholdPolicy.hpp"
+#include "runtime/simpleThresholdPolicy.inline.hpp"
+#ifdef TIERED
+// Print an event.
+void AdvancedThresholdPolicy::print_specific(EventType type, methodHandle mh, 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));
+}
+void AdvancedThresholdPolicy::initialize() {
+// Turn on ergonomic compiler count selection
+if (FLAG_IS_DEFAULT(CICompilerCountPerCPU) && FLAG_IS_DEFAULT(CICompilerCount)) {
+FLAG_SET_DEFAULT(CICompilerCountPerCPU, true);
+}
+int count = CICompilerCount;
+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, 1) * 3 / 2;
+}
+set_c1_count(MAX2(count / 3, 1));
+set_c2_count(MAX2(count - c1_count(), 1));
+FLAG_SET_ERGO(intx, CICompilerCount, c1_count() + c2_count());
+// Some inlining tuning
+#ifdef X86
+if (FLAG_IS_DEFAULT(InlineSmallCode)) {
+FLAG_SET_DEFAULT(InlineSmallCode, 2000);
+}
+#endif
+#ifdef SPARC
+if (FLAG_IS_DEFAULT(InlineSmallCode)) {
+FLAG_SET_DEFAULT(InlineSmallCode, 2500);
+}
+#endif
+set_increase_threshold_at_ratio();
+set_start_time(os::javaTimeMillis());
+}
+// update_rate() is called from select_task() while holding a compile queue lock.
+void AdvancedThresholdPolicy::update_rate(jlong t, Method* m) {
+JavaThread* THREAD = JavaThread::current();
+if (is_old(m)) {
+// We don't remove old methods from the queue,
+// so we can just zero the rate.
+m->set_rate(0, THREAD);
+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, THREAD);
+m->set_prev_event_count(event_count, THREAD);
+m->set_rate((float)delta_e / (float)delta_t, THREAD); // 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, THREAD);
+}
+}
+}
+// Check if this method has been stale from a given number of milliseconds.
+// See select_task().
+bool AdvancedThresholdPolicy::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 AdvancedThresholdPolicy::is_old(Method* method) {
+return method->invocation_count() > 50000 || method->backedge_count() > 500000;
+}
+double AdvancedThresholdPolicy::weight(Method* method) {
+return (method->rate() + 1) * ((method->invocation_count() + 1) *  (method->backedge_count() + 1));
+}
+// Apply heuristics and return true if x should be compiled before y
+bool AdvancedThresholdPolicy::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 AdvancedThresholdPolicy::is_method_profiled(Method* method) {
+MethodData* mdo = method->method_data();
+if (mdo != NULL) {
+int i = mdo->invocation_count_delta();
+int b = mdo->backedge_count_delta();
+return call_predicate_helper<CompLevel_full_profile>(i, b, 1);
+}
+return false;
+}
+// Called with the queue locked and with at least one element
+CompileTask* AdvancedThresholdPolicy::select_task(CompileQueue* compile_queue) {
+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();
+MethodData* mdo = method->method_data();
+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.
+if (is_stale(t, TieredCompileTaskTimeout, method) && !is_old(method)) {
+if (PrintTieredEvents) {
+print_event(REMOVE_FROM_QUEUE, method, method, task->osr_bci(), (CompLevel)task->comp_level());
+}
+CompileTaskWrapper ctw(task); // Frees the task
+compile_queue->remove(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;
+}
+}
+task = next_task;
+}
+if (max_task->comp_level() == CompLevel_full_profile && TieredStopAtLevel > CompLevel_full_profile
+&& 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;
+}
+double AdvancedThresholdPolicy::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();
+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 AdvancedThresholdPolicy::loop_predicate(int i, int b, CompLevel cur_level) {
+switch(cur_level) {
+case CompLevel_none:
+case CompLevel_limited_profile: {
+double k = threshold_scale(CompLevel_full_profile, Tier3LoadFeedback);
+return loop_predicate_helper<CompLevel_none>(i, b, k);
+}
+case CompLevel_full_profile: {
+double k = threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback);
+return loop_predicate_helper<CompLevel_full_profile>(i, b, k);
+}
+default:
+return true;
+}
+}
+bool AdvancedThresholdPolicy::call_predicate(int i, int b, CompLevel cur_level) {
+switch(cur_level) {
+case CompLevel_none:
+case CompLevel_limited_profile: {
+double k = threshold_scale(CompLevel_full_profile, Tier3LoadFeedback);
+return call_predicate_helper<CompLevel_none>(i, b, k);
+}
+case CompLevel_full_profile: {
+double k = threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback);
+return call_predicate_helper<CompLevel_full_profile>(i, b, k);
+}
+default:
+return true;
+}
+}
+// 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 AdvancedThresholdPolicy::should_create_mdo(Method* method, CompLevel cur_level) {
+if (cur_level == CompLevel_none &&
+CompileBroker::queue_size(CompLevel_full_optimization) <=
+Tier3DelayOn * compiler_count(CompLevel_full_optimization)) {
+int i = method->invocation_count();
+int b = method->backedge_count();
+double k = Tier0ProfilingStartPercentage / 100.0;
+return call_predicate_helper<CompLevel_none>(i, b, k) || loop_predicate_helper<CompLevel_none>(i, b, k);
+}
+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 AdvancedThresholdPolicy::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 AdvancedThresholdPolicy::create_mdo(methodHandle mh, JavaThread* THREAD) {
+if (mh->is_native() || mh->is_abstract() || mh->is_accessor()) 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 occures 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, 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 AdvancedThresholdPolicy::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) {
+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)) {
+// 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))) {
+next_level = CompLevel_full_profile;
+}
+} else {
+next_level = CompLevel_full_optimization;
+}
+}
+}
+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)) {
+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 AdvancedThresholdPolicy::call_event(Method* method, CompLevel cur_level) {
+CompLevel osr_level = MIN2((CompLevel) method->highest_osr_comp_level(),
+common(&AdvancedThresholdPolicy::loop_predicate, method, cur_level, true));
+CompLevel next_level = common(&AdvancedThresholdPolicy::call_predicate, method, cur_level);
+// If OSR method level is greater than the regular method level, the levels should be
+// equalized by raising the regular method level in order to avoid OSRs during each
+// invocation of the method.
+if (osr_level == CompLevel_full_optimization && cur_level == CompLevel_full_profile) {
+MethodData* mdo = method->method_data();
+guarantee(mdo != NULL, "MDO should not be NULL");
+if (mdo->invocation_count() >= 1) {
+next_level = CompLevel_full_optimization;
+}
+} else {
+next_level = MAX2(osr_level, next_level);
+}
+return next_level;
+}
+// Determine if we should do an OSR compilation of a given method.
+CompLevel AdvancedThresholdPolicy::loop_event(Method* method, CompLevel cur_level) {
+CompLevel next_level = common(&AdvancedThresholdPolicy::loop_predicate, method, cur_level, true);
+if (cur_level == CompLevel_none) {
+// If there is a live OSR method that means that we deopted to the interpreter
+// for the transition.
+CompLevel osr_level = MIN2((CompLevel)method->highest_osr_comp_level(), next_level);
+if (osr_level > CompLevel_none) {
+return osr_level;
+}
+}
+return next_level;
+}
+// Update the rate and submit compile
+void AdvancedThresholdPolicy::submit_compile(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, "tiered", thread);
+}
+// Handle the invocation event.
+void AdvancedThresholdPolicy::method_invocation_event(methodHandle mh, methodHandle imh,
+CompLevel level, nmethod* nm, JavaThread* thread) {
+if (should_create_mdo(mh(), level)) {
+create_mdo(mh, thread);
+}
+if (is_compilation_enabled() && !CompileBroker::compilation_is_in_queue(mh, InvocationEntryBci)) {
+CompLevel next_level = call_event(mh(), level);
+if (next_level != level) {
+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 AdvancedThresholdPolicy::method_back_branch_event(methodHandle mh, methodHandle imh,
+int bci, CompLevel level, nmethod* 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);
+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, bci) && 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
+guarantee(nm != NULL, "Should have nmethod here");
+cur_level = comp_level(mh());
+next_level = call_event(mh(), cur_level);
+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();
+}
+}
+if (!CompileBroker::compilation_is_in_queue(mh, InvocationEntryBci)) {
+// 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) {
+compile(mh, InvocationEntryBci, next_level, thread);
+}
+}
+} else {
+cur_level = comp_level(imh());
+next_level = call_event(imh(), cur_level);
+if (!CompileBroker::compilation_is_in_queue(imh, bci) && next_level != cur_level) {
+compile(imh, InvocationEntryBci, next_level, thread);
+}
+}
+}
+}
+#endif // TIERED

Mercurial > jdk8-mips64-public > hotspot / file comparison

comparison: src/share/vm/runtime/advancedThresholdPolicy.cpp

src/share/vm/runtime/advancedThresholdPolicy.cpp