Mercurial > hg > truffle
view src/share/vm/runtime/advancedThresholdPolicy.cpp @ 7432:0b3d19153cc6
8001028: Improve GC option handling
Summary: If there are not enough native resources to create the ReferenceHandler or Finalizer Java threads, the VM will attempt to throw an OOME before the java.lang.Class class has been initialized. This can result in assertion failures and other crashes. Move the initialization of the java.lang.Class class to just before the initialization of the java.lang.ref.Finalizer class.
Reviewed-by: jwilhelm, dholmes, coleenp
author | johnc |
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date | Wed, 12 Dec 2012 12:07:32 -0800 |
parents | d8ce2825b193 |
children | aeaca88565e6 |
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/* * Copyright (c) 2010, 2012, 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 - count / 3, 1)); // 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_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) { 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 (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; 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