Mercurial > hg > truffle
view src/share/vm/interpreter/invocationCounter.cpp @ 20543:e7d0505c8a30
8059758: Footprint regressions with JDK-8038423
Summary: Changes in JDK-8038423 always initialize (zero out) virtual memory used for auxiliary data structures. This causes a footprint regression for G1 in startup benchmarks. This is because they do not touch that memory at all, so the operating system does not actually commit these pages. The fix is to, if the initialization value of the data structures matches the default value of just committed memory (=0), do not do anything.
Reviewed-by: jwilhelm, brutisso
author | tschatzl |
---|---|
date | Fri, 10 Oct 2014 15:51:58 +0200 |
parents | aeaca88565e6 |
children | 836a62f43af9 |
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/* * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #include "precompiled.hpp" #include "interpreter/invocationCounter.hpp" #include "runtime/frame.hpp" #include "runtime/handles.inline.hpp" // Implementation of InvocationCounter void InvocationCounter::init() { _counter = 0; // reset all the bits, including the sticky carry reset(); } void InvocationCounter::reset() { // Only reset the state and don't make the method look like it's never // been executed set_state(wait_for_compile); } void InvocationCounter::set_carry() { set_carry_flag(); // The carry bit now indicates that this counter had achieved a very // large value. Now reduce the value, so that the method can be // executed many more times before re-entering the VM. int old_count = count(); int new_count = MIN2(old_count, (int) (CompileThreshold / 2)); // prevent from going to zero, to distinguish from never-executed methods if (new_count == 0) new_count = 1; if (old_count != new_count) set(state(), new_count); } void InvocationCounter::set_state(State state) { assert(0 <= state && state < number_of_states, "illegal state"); int init = _init[state]; // prevent from going to zero, to distinguish from never-executed methods if (init == 0 && count() > 0) init = 1; int carry = (_counter & carry_mask); // the carry bit is sticky _counter = (init << number_of_noncount_bits) | carry | state; } void InvocationCounter::print() { tty->print_cr("invocation count: up = %d, limit = %d, carry = %s, state = %s", count(), limit(), carry() ? "true" : "false", state_as_string(state())); } void InvocationCounter::print_short() { tty->print(" [%d%s;%s]", count(), carry()?"+carry":"", state_as_short_string(state())); } // Initialization int InvocationCounter::_init [InvocationCounter::number_of_states]; InvocationCounter::Action InvocationCounter::_action[InvocationCounter::number_of_states]; int InvocationCounter::InterpreterInvocationLimit; int InvocationCounter::InterpreterBackwardBranchLimit; int InvocationCounter::InterpreterProfileLimit; const char* InvocationCounter::state_as_string(State state) { switch (state) { case wait_for_nothing : return "wait_for_nothing"; case wait_for_compile : return "wait_for_compile"; } ShouldNotReachHere(); return NULL; } const char* InvocationCounter::state_as_short_string(State state) { switch (state) { case wait_for_nothing : return "not comp."; case wait_for_compile : return "compileable"; } ShouldNotReachHere(); return NULL; } static address do_nothing(methodHandle method, TRAPS) { // dummy action for inactive invocation counters MethodCounters* mcs = method->method_counters(); assert(mcs != NULL, ""); mcs->invocation_counter()->set_carry(); mcs->invocation_counter()->set_state(InvocationCounter::wait_for_nothing); return NULL; } static address do_decay(methodHandle method, TRAPS) { // decay invocation counters so compilation gets delayed MethodCounters* mcs = method->method_counters(); assert(mcs != NULL, ""); mcs->invocation_counter()->decay(); return NULL; } void InvocationCounter::def(State state, int init, Action action) { assert(0 <= state && state < number_of_states, "illegal state"); assert(0 <= init && init < count_limit, "initial value out of range"); _init [state] = init; _action[state] = action; } address dummy_invocation_counter_overflow(methodHandle m, TRAPS) { ShouldNotReachHere(); return NULL; } void InvocationCounter::reinitialize(bool delay_overflow) { // define states guarantee((int)number_of_states <= (int)state_limit, "adjust number_of_state_bits"); def(wait_for_nothing, 0, do_nothing); if (delay_overflow) { def(wait_for_compile, 0, do_decay); } else { def(wait_for_compile, 0, dummy_invocation_counter_overflow); } InterpreterInvocationLimit = CompileThreshold << number_of_noncount_bits; InterpreterProfileLimit = ((CompileThreshold * InterpreterProfilePercentage) / 100)<< number_of_noncount_bits; // When methodData is collected, the backward branch limit is compared against a // methodData counter, rather than an InvocationCounter. In the former case, we // don't need the shift by number_of_noncount_bits, but we do need to adjust // the factor by which we scale the threshold. if (ProfileInterpreter) { InterpreterBackwardBranchLimit = (CompileThreshold * (OnStackReplacePercentage - InterpreterProfilePercentage)) / 100; } else { InterpreterBackwardBranchLimit = ((CompileThreshold * OnStackReplacePercentage) / 100) << number_of_noncount_bits; } assert(0 <= InterpreterBackwardBranchLimit, "OSR threshold should be non-negative"); assert(0 <= InterpreterProfileLimit && InterpreterProfileLimit <= InterpreterInvocationLimit, "profile threshold should be less than the compilation threshold " "and non-negative"); } void invocationCounter_init() { InvocationCounter::reinitialize(DelayCompilationDuringStartup); }