src/share/vm/gc_implementation/g1/g1Allocator_ext.cpp

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

author
tschatzl
date
Fri, 10 Oct 2014 15:51:58 +0200
changeset 7257
e7d0505c8a30
parent 7118
227a9e5e4b4a
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

sjohanss@7118 1 /*
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sjohanss@7118 7 * published by the Free Software Foundation.
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sjohanss@7118 9 * This code is distributed in the hope that it will be useful, but WITHOUT
sjohanss@7118 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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sjohanss@7118 12 * version 2 for more details (a copy is included in the LICENSE file that
sjohanss@7118 13 * accompanied this code).
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sjohanss@7118 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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sjohanss@7118 24
sjohanss@7118 25 #include "precompiled.hpp"
sjohanss@7118 26 #include "gc_implementation/g1/g1Allocator.hpp"
sjohanss@7118 27 #include "gc_implementation/g1/g1CollectedHeap.hpp"
sjohanss@7118 28
sjohanss@7118 29 G1Allocator* G1Allocator::create_allocator(G1CollectedHeap* g1h) {
sjohanss@7118 30 return new G1DefaultAllocator(g1h);
sjohanss@7118 31 }
sjohanss@7118 32
sjohanss@7118 33 G1ParGCAllocator* G1ParGCAllocator::create_allocator(G1CollectedHeap* g1h) {
sjohanss@7118 34 return new G1DefaultParGCAllocator(g1h);
sjohanss@7118 35 }

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