src/share/vm/gc_implementation/g1/g1YCTypes.hpp

Fri, 10 Oct 2014 15:51:58 +0200

author
tschatzl
date
Fri, 10 Oct 2014 15:51:58 +0200
changeset 7257
e7d0505c8a30
parent 0
f90c822e73f8
permissions
-rw-r--r--

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

aoqi@0 1 /*
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aoqi@0 5 * This code is free software; you can redistribute it and/or modify it
aoqi@0 6 * under the terms of the GNU General Public License version 2 only, as
aoqi@0 7 * published by the Free Software Foundation.
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aoqi@0 9 * This code is distributed in the hope that it will be useful, but WITHOUT
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aoqi@0 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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aoqi@0 24
aoqi@0 25 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1YCTYPES_HPP
aoqi@0 26 #define SHARE_VM_GC_IMPLEMENTATION_G1_G1YCTYPES_HPP
aoqi@0 27
aoqi@0 28 #include "utilities/debug.hpp"
aoqi@0 29
aoqi@0 30 enum G1YCType {
aoqi@0 31 Normal,
aoqi@0 32 InitialMark,
aoqi@0 33 DuringMark,
aoqi@0 34 Mixed,
aoqi@0 35 G1YCTypeEndSentinel
aoqi@0 36 };
aoqi@0 37
aoqi@0 38 class G1YCTypeHelper {
aoqi@0 39 public:
aoqi@0 40 static const char* to_string(G1YCType type) {
aoqi@0 41 switch(type) {
aoqi@0 42 case Normal: return "Normal";
aoqi@0 43 case InitialMark: return "Initial Mark";
aoqi@0 44 case DuringMark: return "During Mark";
aoqi@0 45 case Mixed: return "Mixed";
aoqi@0 46 default: ShouldNotReachHere(); return NULL;
aoqi@0 47 }
aoqi@0 48 }
aoqi@0 49 };
aoqi@0 50
aoqi@0 51 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1YCTYPES_HPP

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