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8202711: Merge tiered compilation policies

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Reviewed-by: neliasso, kvn
This commit is contained in:
Claes Redestad 2018-05-09 09:39:25 +02:00
parent a322e0f0ff
commit 7101b28dc3
11 changed files with 647 additions and 1054 deletions
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src/hotspot/share/runtime/advancedThresholdPolicy.cpp
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@ -1,667 +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 "code/codeCache.hpp"
#include "runtime/advancedThresholdPolicy.hpp"
#include "runtime/handles.inline.hpp"
#include "runtime/simpleThresholdPolicy.inline.hpp"
#if INCLUDE_JVMCI
#include "jvmci/jvmciRuntime.hpp"
#endif
#ifdef TIERED
// Print an event.
void AdvancedThresholdPolicy::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));
}
void AdvancedThresholdPolicy::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());
}
// update_rate() is called from select_task() while holding a compile queue lock.
void AdvancedThresholdPolicy::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 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 (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 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, method);
}
return false;
}
// Called with the queue locked and with at least one element
CompileTask* AdvancedThresholdPolicy::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->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(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 AdvancedThresholdPolicy::loop_predicate(int i, int b, CompLevel cur_level, Method* method) {
switch(cur_level) {
case CompLevel_aot: {
double k = threshold_scale(CompLevel_full_profile, Tier3LoadFeedback);
return loop_predicate_helper<CompLevel_aot>(i, b, k, method);
}
case CompLevel_none:
case CompLevel_limited_profile: {
double k = threshold_scale(CompLevel_full_profile, Tier3LoadFeedback);
return loop_predicate_helper<CompLevel_none>(i, b, k, method);
}
case CompLevel_full_profile: {
double k = threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback);
return loop_predicate_helper<CompLevel_full_profile>(i, b, k, method);
}
default:
return true;
}
}
bool AdvancedThresholdPolicy::call_predicate(int i, int b, CompLevel cur_level, Method* method) {
switch(cur_level) {
case CompLevel_aot: {
double k = threshold_scale(CompLevel_full_profile, Tier3LoadFeedback);
return call_predicate_helper<CompLevel_aot>(i, b, k, method);
}
case CompLevel_none:
case CompLevel_limited_profile: {
double k = threshold_scale(CompLevel_full_profile, Tier3LoadFeedback);
return call_predicate_helper<CompLevel_none>(i, b, k, method);
}
case CompLevel_full_profile: {
double k = threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback);
return call_predicate_helper<CompLevel_full_profile>(i, b, k, method);
}
default:
return true;
}
}
// 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, method) || loop_predicate_helper<CompLevel_none>(i, b, k, method);
}
return false;
}
// Inlining control: if we're compiling a profiled method with C1 and the callee
// is known to have OSRed in a C2 version, don't inline it.
bool 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(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 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) {
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 AdvancedThresholdPolicy::call_event(Method* method, CompLevel cur_level, JavaThread * thread) {
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);
}
#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 AdvancedThresholdPolicy::loop_event(Method* method, CompLevel cur_level, JavaThread * thread) {
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;
}
}
#if INCLUDE_JVMCI
if (UseJVMCICompiler) {
next_level = JVMCIRuntime::adjust_comp_level(method, true, next_level, thread);
}
#endif
return next_level;
}
// Update the rate and submit compile
void AdvancedThresholdPolicy::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);
}
bool AdvancedThresholdPolicy::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 AdvancedThresholdPolicy::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 AdvancedThresholdPolicy::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 // TIERED

235
src/hotspot/share/runtime/advancedThresholdPolicy.hpp
View File

@ -1,235 +0,0 @@
/*
* Copyright (c) 2010, 2017, 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_ADVANCEDTHRESHOLDPOLICY_HPP
#define SHARE_VM_RUNTIME_ADVANCEDTHRESHOLDPOLICY_HPP
#include "runtime/simpleThresholdPolicy.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 AdvancedThresholdPolicy : public SimpleThresholdPolicy {
jlong _start_time;
// Call and loop predicates determine whether a transition to a higher compilation
// level should be performed (pointers to predicate functions are passed to common().
// Predicates also take compiler load into account.
typedef bool (AdvancedThresholdPolicy::*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);
// 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:
void print_specific(EventType type, const methodHandle& mh, const methodHandle& imh, int bci, CompLevel level);
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; }
// Submit a given method for compilation (and update the rate).
virtual void submit_compile(const methodHandle& mh, int bci, CompLevel level, JavaThread* thread);
// event() from SimpleThresholdPolicy would call these.
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);
public:
AdvancedThresholdPolicy() : _start_time(0) { }
// Select task is called by CompileBroker. We should return a task or NULL.
virtual CompileTask* select_task(CompileQueue* compile_queue);
virtual void initialize();
virtual bool should_not_inline(ciEnv* env, ciMethod* callee);
};
#endif // TIERED
#endif // SHARE_VM_RUNTIME_ADVANCEDTHRESHOLDPOLICY_HPP

4
src/hotspot/share/runtime/arguments.cpp
View File

@ -1603,9 +1603,9 @@ intx Arguments::scaled_freq_log(intx freq_log, double scale) {
}
void Arguments::set_tiered_flags() {
// With tiered, set default policy to AdvancedThresholdPolicy, which is 3.
// With tiered, set default policy to SimpleThresholdPolicy, which is 2.
if (FLAG_IS_DEFAULT(CompilationPolicyChoice)) {
FLAG_SET_DEFAULT(CompilationPolicyChoice, 3);
FLAG_SET_DEFAULT(CompilationPolicyChoice, 2);
}
if (CompilationPolicyChoice < 2) {
vm_exit_during_initialization(

10
src/hotspot/share/runtime/compilationPolicy.cpp
View File

@ -33,7 +33,6 @@
#include "oops/method.inline.hpp"
#include "oops/oop.inline.hpp"
#include "prims/nativeLookup.hpp"
#include "runtime/advancedThresholdPolicy.hpp"
#include "runtime/compilationPolicy.hpp"
#include "runtime/frame.hpp"
#include "runtime/handles.inline.hpp"
@ -72,17 +71,10 @@ void compilationPolicy_init() {
CompilationPolicy::set_policy(new SimpleThresholdPolicy());
#else
Unimplemented();
#endif
break;
case 3:
#ifdef TIERED
CompilationPolicy::set_policy(new AdvancedThresholdPolicy());
#else
Unimplemented();
#endif
break;
default:
fatal("CompilationPolicyChoice must be in the range: [0-3]");
fatal("CompilationPolicyChoice must be in the range: [0-2]");
}
CompilationPolicy::policy()->initialize();
}

4
src/hotspot/share/runtime/globals.hpp
View File

@ -1158,8 +1158,8 @@ define_pd_global(uint64_t,MaxRAM, 1ULL*G);
"UseDynamicNumberOfCompilerThreads") \
\
product(intx, CompilationPolicyChoice, 0, \
"which compilation policy (0-3)") \
range(0, 3) \
"which compilation policy (0-2)") \
range(0, 2) \
\
develop(bool, UseStackBanging, true, \
"use stack banging for stack overflow checks (required for " \

523
src/hotspot/share/runtime/simpleThresholdPolicy.cpp
View File

@ -140,20 +140,33 @@ void SimpleThresholdPolicy::print_event(EventType type, const methodHandle& mh,
}
void SimpleThresholdPolicy::initialize() {
if (FLAG_IS_DEFAULT(CICompilerCount)) {
FLAG_SET_DEFAULT(CICompilerCount, 3);
}
int count = CICompilerCount;
#ifdef _LP64
// On 64-bit systems, scale the number of compiler threads with
// the number of cores available on the system. Scaling is not
// performed on 32-bit systems because it can lead to exhaustion
// of the virtual memory address space available to the JVM.
// Turn on ergonomic compiler count selection
if (FLAG_IS_DEFAULT(CICompilerCountPerCPU) && FLAG_IS_DEFAULT(CICompilerCount)) {
FLAG_SET_DEFAULT(CICompilerCountPerCPU, true);
}
if (CICompilerCountPerCPU) {
count = MAX2(log2_intptr(os::active_processor_count()) * 3 / 2, 2);
// 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);
@ -162,6 +175,22 @@ void SimpleThresholdPolicy::initialize() {
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) {
@ -186,7 +215,66 @@ void SimpleThresholdPolicy::handle_counter_overflow(Method* method) {
// Called with the queue locked and with at least one element
CompileTask* SimpleThresholdPolicy::select_task(CompileQueue* compile_queue) {
return select_task_helper(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->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;
}
void SimpleThresholdPolicy::reprofile(ScopeDesc* trap_scope, bool is_osr) {
@ -284,26 +372,150 @@ void SimpleThresholdPolicy::compile(const methodHandle& mh, int bci, CompLevel l
}
}
// Tell the broker to compile the method
// 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<CompLevel_full_profile>(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() transition function).
// 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: {
return loop_predicate_helper<CompLevel_aot>(i, b, 1.0, method);
double k = threshold_scale(CompLevel_full_profile, Tier3LoadFeedback);
return loop_predicate_helper<CompLevel_aot>(i, b, k, method);
}
case CompLevel_none:
case CompLevel_limited_profile: {
return loop_predicate_helper<CompLevel_none>(i, b, 1.0, method);
double k = threshold_scale(CompLevel_full_profile, Tier3LoadFeedback);
return loop_predicate_helper<CompLevel_none>(i, b, k, method);
}
case CompLevel_full_profile: {
return loop_predicate_helper<CompLevel_full_profile>(i, b, 1.0, method);
double k = threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback);
return loop_predicate_helper<CompLevel_full_profile>(i, b, k, method);
}
default:
return true;
@ -313,14 +525,17 @@ bool SimpleThresholdPolicy::loop_predicate(int i, int b, CompLevel cur_level, Me
bool SimpleThresholdPolicy::call_predicate(int i, int b, CompLevel cur_level, Method* method) {
switch(cur_level) {
case CompLevel_aot: {
return call_predicate_helper<CompLevel_aot>(i, b, 1.0, method);
double k = threshold_scale(CompLevel_full_profile, Tier3LoadFeedback);
return call_predicate_helper<CompLevel_aot>(i, b, k, method);
}
case CompLevel_none:
case CompLevel_limited_profile: {
return call_predicate_helper<CompLevel_none>(i, b, 1.0, method);
double k = threshold_scale(CompLevel_full_profile, Tier3LoadFeedback);
return call_predicate_helper<CompLevel_none>(i, b, k, method);
}
case CompLevel_full_profile: {
return call_predicate_helper<CompLevel_full_profile>(i, b, 1.0, method);
double k = threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback);
return call_predicate_helper<CompLevel_full_profile>(i, b, k, method);
}
default:
return true;
@ -341,31 +556,167 @@ bool SimpleThresholdPolicy::is_mature(Method* 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<CompLevel_none>(i, b, k, method) || loop_predicate_helper<CompLevel_none>(i, b, k, method);
}
return false;
}
// Inlining control: if we're compiling a profiled method with C1 and the callee
// is known to have OSRed in a C2 version, don't inline it.
bool 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) {
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) && cur_level != CompLevel_aot) {
if (is_trivial(method)) {
next_level = CompLevel_simple;
} else {
switch(cur_level) {
case CompLevel_aot: {
if ((this->*p)(i, b, cur_level, method)) {
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) == CompLevel_full_optimization) {
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)) {
next_level = CompLevel_full_profile;
#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();
@ -382,17 +733,15 @@ CompLevel SimpleThresholdPolicy::common(Predicate p, Method* method, CompLevel c
}
}
break;
default:
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 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));
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
@ -417,7 +766,7 @@ CompLevel SimpleThresholdPolicy::call_event(Method* method, CompLevel cur_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);
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.
@ -434,13 +783,39 @@ CompLevel SimpleThresholdPolicy::loop_event(Method* method, CompLevel cur_level,
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 (is_compilation_enabled() && !CompileBroker::compilation_is_in_queue(mh)) {
CompLevel next_level = call_event(mh(), level, thread);
if (next_level != level) {
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);
}
}
@ -450,25 +825,77 @@ void SimpleThresholdPolicy::method_invocation_event(const methodHandle& mh, cons
// 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 the method is already compiling, quickly bail out.
if (is_compilation_enabled() && !CompileBroker::compilation_is_in_queue(mh)) {
// Use loop event as an opportunity to also check there's been
// enough calls.
CompLevel cur_level = comp_level(mh());
CompLevel next_level = call_event(mh(), cur_level, thread);
CompLevel next_osr_level = loop_event(mh(), level, 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);
}
next_level = MAX2(next_level,
next_osr_level < CompLevel_full_optimization ? next_osr_level : cur_level);
bool is_compiling = false;
if (next_level != cur_level) {
compile(mh, InvocationEntryBci, next_level, thread);
is_compiling = true;
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);
}
// Do the OSR version
if (!is_compiling && next_osr_level != level) {
compile(mh, 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);
}
}
}
}
}

174
src/hotspot/share/runtime/simpleThresholdPolicy.hpp
View File

@ -34,8 +34,136 @@
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).
@ -49,7 +177,7 @@ class SimpleThresholdPolicy : public CompilationPolicy {
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);
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.
@ -58,6 +186,35 @@ class SimpleThresholdPolicy : public CompilationPolicy {
// 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; }
@ -67,7 +224,7 @@ protected:
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) { }
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
@ -87,8 +244,13 @@ protected:
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() : _c1_count(0), _c2_count(0) { }
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();
@ -107,11 +269,7 @@ public:
virtual bool is_mature(Method* method);
// Initialize: set compiler thread count
virtual void initialize();
virtual bool should_not_inline(ciEnv* env, ciMethod* callee) {
return (env->comp_level() == CompLevel_limited_profile ||
env->comp_level() == CompLevel_full_profile) &&
callee->has_loops();
}
virtual bool should_not_inline(ciEnv* env, ciMethod* callee);
};
#endif // TIERED

14
test/hotspot/jtreg/compiler/aot/RecompilationTest.java
View File

@ -37,26 +37,12 @@
* -extraopt -XX:+UnlockDiagnosticVMOptions -extraopt -XX:+WhiteBoxAPI -extraopt -Xbootclasspath/a:.
* -extraopt -XX:-UseCompressedOops
* -extraopt -XX:CompileCommand=dontinline,compiler.whitebox.SimpleTestCaseHelper::*
* @run main/othervm -Xmixed -Xbatch -XX:+UseAOT -XX:+TieredCompilation -XX:CompilationPolicyChoice=2
* -XX:-UseCounterDecay -XX:-UseCompressedOops
* -XX:-Inline
* -XX:AOTLibrary=./libRecompilationTest1.so -Xbootclasspath/a:.
* -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI
* -Dcompiler.aot.RecompilationTest.check_level=1
* compiler.aot.RecompilationTest
* @run driver compiler.aot.AotCompiler -libname libRecompilationTest2.so
* -class compiler.whitebox.SimpleTestCaseHelper
* -extraopt -Dgraal.TieredAOT=false
* -extraopt -XX:+UnlockDiagnosticVMOptions -extraopt -XX:+WhiteBoxAPI -extraopt -Xbootclasspath/a:.
* -extraopt -XX:-UseCompressedOops
* -extraopt -XX:CompileCommand=dontinline,compiler.whitebox.SimpleTestCaseHelper::*
* @run main/othervm -Xmixed -Xbatch -XX:+UseAOT -XX:+TieredCompilation -XX:CompilationPolicyChoice=2
* -XX:-UseCounterDecay -XX:-UseCompressedOops
* -XX:-Inline
* -XX:AOTLibrary=./libRecompilationTest2.so -Xbootclasspath/a:.
* -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI
* -Dcompiler.aot.RecompilationTest.check_level=-1
* compiler.aot.RecompilationTest
* @run main/othervm -Xmixed -Xbatch -XX:+UseAOT -XX:-TieredCompilation
* -XX:-UseCounterDecay -XX:-UseCompressedOops
* -XX:-Inline

3
test/hotspot/jtreg/compiler/tiered/ConstantGettersTransitionsTest.java
View File

@ -34,7 +34,6 @@
* @run main/othervm/timeout=240 -Xmixed -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions
* -XX:+WhiteBoxAPI -XX:+TieredCompilation -XX:-UseCounterDecay
* -XX:CompileCommand=compileonly,compiler.tiered.ConstantGettersTransitionsTest$ConstantGettersTestCase$TrivialMethods::*
* compiler.tiered.TransitionsTestExecutor
* compiler.tiered.ConstantGettersTransitionsTest
*/
@ -200,4 +199,4 @@ public class ConstantGettersTransitionsTest extends LevelTransitionTest {
}
}
}
}
}

1
test/hotspot/jtreg/compiler/tiered/LevelTransitionTest.java
View File

@ -36,7 +36,6 @@
* -XX:+WhiteBoxAPI -XX:+TieredCompilation -XX:-UseCounterDecay
* -XX:CompileCommand=compileonly,compiler.whitebox.SimpleTestCaseHelper::*
* -XX:CompileCommand=compileonly,compiler.tiered.LevelTransitionTest$ExtendedTestCase$CompileMethodHolder::*
* compiler.tiered.TransitionsTestExecutor
* compiler.tiered.LevelTransitionTest
*/

66
test/hotspot/jtreg/compiler/tiered/TransitionsTestExecutor.java
View File

@ -1,66 +0,0 @@
/*
* Copyright (c) 2014, 2016, 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.
*/
package compiler.tiered;
import compiler.whitebox.CompilerWhiteBoxTest;
import jdk.test.lib.process.OutputAnalyzer;
import jdk.test.lib.process.ProcessTools;
import java.lang.management.ManagementFactory;
import java.lang.management.RuntimeMXBean;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
/**
* Executes given test in a separate VM with enabled Tiered Compilation for
* CompilationPolicyChoice 2 and 3
*/
public class TransitionsTestExecutor {
public static void main(String[] args) throws Throwable {
if (CompilerWhiteBoxTest.skipOnTieredCompilation(false)) {
return;
}
if (args.length != 1) {
throw new Error("TESTBUG: Test name should be specified");
}
executeTestFor(2, args[0]);
executeTestFor(3, args[0]);
}
private static void executeTestFor(int compilationPolicy, String testName) throws Throwable {
String policy = "-XX:CompilationPolicyChoice=" + compilationPolicy;
// Get runtime arguments including VM options given to this executor
RuntimeMXBean runtime = ManagementFactory.getRuntimeMXBean();
List<String> vmArgs = runtime.getInputArguments();
// Construct execution command with compilation policy choice and test name
List<String> args = new ArrayList<>(vmArgs);
Collections.addAll(args, policy, testName);
OutputAnalyzer out = ProcessTools.executeTestJvm(args.toArray(new String[args.size()]));
out.shouldHaveExitValue(0);
}
}