8172990: [AOT] Missing GC scan of _metaspace_got array containing Klass*
Summary: added back _metaspace_got array scan.
Reviewed-by: dlong
--- a/hotspot/src/jdk.aot/share/classes/jdk.tools.jaotc/src/jdk/tools/jaotc/CallSiteRelocationSymbol.java Wed Jan 18 10:30:56 2017 -0500
+++ b/hotspot/src/jdk.aot/share/classes/jdk.tools.jaotc/src/jdk/tools/jaotc/CallSiteRelocationSymbol.java Wed Jan 18 14:36:54 2017 -0800
@@ -59,12 +59,6 @@
addExternalPltToGotRelocation(binaryContainer, symbol, relocationOffset);
}
- protected static void addMetaspaceGotRelocation(BinaryContainer binaryContainer, String symbolName, int symbolOffset, int relocationOffset) {
- ByteContainer container = binaryContainer.getMetaspaceGotContainer();
- Symbol symbol = container.createGotSymbol(symbolOffset, symbolName);
- addExternalPltToGotRelocation(binaryContainer, symbol, relocationOffset);
- }
-
/**
* Add an {@link RelocType#EXTERNAL_GOT_TO_PLT} relocation to the
* {@link BinaryContainer#getExtLinkageGOTContainer()}.
--- a/hotspot/src/jdk.aot/share/classes/jdk.tools.jaotc/src/jdk/tools/jaotc/JavaCallSiteRelocationSymbol.java Wed Jan 18 10:30:56 2017 -0500
+++ b/hotspot/src/jdk.aot/share/classes/jdk.tools.jaotc/src/jdk/tools/jaotc/JavaCallSiteRelocationSymbol.java Wed Jan 18 14:36:54 2017 -0800
@@ -37,6 +37,7 @@
final class JavaCallSiteRelocationSymbol extends CallSiteRelocationSymbol {
private static final byte[] zeroSlot = new byte[8];
+ // -1 represents Universe::non_oop_word() value
private static final byte[] minusOneSlot = {-1, -1, -1, -1, -1, -1, -1, -1};
public JavaCallSiteRelocationSymbol(CompiledMethodInfo mi, Call call, CallSiteRelocationInfo callSiteRelocation, BinaryContainer binaryContainer) {
@@ -79,30 +80,39 @@
}
// Add relocation to GOT cell for call resolution jump.
+ // This GOT cell will be initialized during JVM startup with address
+ // of JVM runtime call resolution function.
String gotSymbolName = "got." + getResolveSymbolName(binaryContainer, mi, call);
Symbol gotSymbol = binaryContainer.getGotSymbol(gotSymbolName);
addExternalPltToGotRelocation(binaryContainer, gotSymbol, stub.getResolveJumpOffset());
// Add relocation to resolve call jump instruction address for GOT cell.
+ // This GOT cell will be initialized with address of resolution jump instruction and
+ // will be updated with call destination address by JVM runtime call resolution code.
String pltJmpSymbolName = relocationSymbolName("plt.jmp", mi, call, callSiteRelocation);
addCodeContainerRelocation(binaryContainer, pltJmpSymbolName, stub.getResolveJumpStart(), gotStartOffset);
// Add relocation to GOT cell for dispatch jump.
+ // The dispatch jump loads destination address from this GOT cell.
String gotEntrySymbolName = relocationSymbolName("got.entry", mi, call, callSiteRelocation);
addExtLinkageGotContainerRelocation(binaryContainer, gotEntrySymbolName, gotStartOffset, stub.getDispatchJumpOffset());
- // Virtual call needs initial -1 value.
+ // Virtual call needs initial -1 value for Klass pointer.
+ // Non virtual call needs initial 0 value for Method pointer to call c2i adapter.
byte[] slot = isVirtualCall ? minusOneSlot : zeroSlot;
- final int gotMetaOffset = binaryContainer.appendMetaspaceGotBytes(slot, 0, slot.length);
+ final int gotMetaOffset = binaryContainer.appendExtLinkageGotBytes(slot, 0, slot.length);
// Add relocation to GOT cell for move instruction (Klass* for virtual, Method* otherwise).
String gotMoveSymbolName = relocationSymbolName("got.move", mi, call, callSiteRelocation);
- addMetaspaceGotRelocation(binaryContainer, gotMoveSymbolName, gotMetaOffset, stub.getMovOffset());
+ addExtLinkageGotContainerRelocation(binaryContainer, gotMoveSymbolName, gotMetaOffset, stub.getMovOffset());
if (isVirtualCall) {
// Nothing.
} else {
// Add relocation to GOT cell for c2i adapter jump.
+ // The c2i jump instruction loads destination address from this GOT cell.
+ // This GOT cell is initialized with -1 and will be updated
+ // by JVM runtime call resolution code.
String gotC2ISymbolName = relocationSymbolName("got.c2i", mi, call, callSiteRelocation);
addExtLinkageGotContainerRelocation(binaryContainer, gotC2ISymbolName, gotStartOffset + 8, stub.getC2IJumpOffset());
}
--- a/hotspot/src/share/vm/aot/aotCodeHeap.cpp Wed Jan 18 10:30:56 2017 -0500
+++ b/hotspot/src/share/vm/aot/aotCodeHeap.cpp Wed Jan 18 14:36:54 2017 -0800
@@ -830,38 +830,19 @@
}
}
-// Yes, this is faster than going through the relocations,
-// but there are two problems:
-// 1) GOT slots are sometimes patched with non-Metadata values
-// 2) We don't want to scan metadata for dead methods
-// Unfortunately we don't know if the metadata belongs to
-// live aot methods or not, so process them all. If this
-// is for mark_on_stack, some old methods may stick around
-// forever instead of getting cleaned up.
+// Scan only metaspace_got cells which should have only Klass*,
+// metadata_got cells are scanned only for alive AOT methods
+// by AOTCompiledMethod::metadata_do().
void AOTCodeHeap::got_metadata_do(void f(Metadata*)) {
for (int i = 1; i < _metaspace_got_size; i++) {
Metadata** p = &_metaspace_got[i];
Metadata* md = *p;
if (md == NULL) continue; // skip non-oops
- intptr_t meta = (intptr_t)md;
- if (meta == -1) continue; // skip non-oops
if (Metaspace::contains(md)) {
f(md);
- }
- }
- for (int i = 1; i < _metadata_got_size; i++) {
- Metadata** p = &_metadata_got[i];
- Metadata* md = *p;
- intptr_t meta = (intptr_t)md;
- if ((meta & 1) == 1) {
- // already resolved
- md = (Metadata*)(meta & ~1);
} else {
- continue;
- }
- if (md == NULL) continue; // skip non-oops
- if (Metaspace::contains(md)) {
- f(md);
+ intptr_t meta = (intptr_t)md;
+ fatal("Invalid value in _metaspace_got[%d] = " INTPTR_FORMAT, i, meta);
}
}
}
@@ -910,8 +891,6 @@
aot->metadata_do(f);
}
}
-#if 0
- // With the marking above, this call doesn't seem to be needed
+ // Scan metaspace_got cells.
got_metadata_do(f);
-#endif
}
--- a/hotspot/src/share/vm/aot/aotCompiledMethod.cpp Wed Jan 18 10:30:56 2017 -0500
+++ b/hotspot/src/share/vm/aot/aotCompiledMethod.cpp Wed Jan 18 14:36:54 2017 -0800
@@ -71,15 +71,6 @@
}
#endif
-void AOTCompiledMethod::oops_do(OopClosure* f) {
- if (_oop != NULL) {
- f->do_oop(&_oop);
- }
-#if 0
- metadata_oops_do(metadata_begin(), metadata_end(), f);
-#endif
-}
-
bool AOTCompiledMethod::do_unloading_oops(address low_boundary, BoolObjectClosure* is_alive, bool unloading_occurred) {
return false;
}
@@ -161,9 +152,6 @@
*entry = (Metadata*)meta; // Should be atomic on x64
return (Metadata*)m;
}
- // need to resolve it here..., patching of GOT need to be CAS or atomic operation.
- // FIXIT: need methods for debuginfo.
- // return _method;
}
ShouldNotReachHere(); return NULL;
}
@@ -288,11 +276,19 @@
f(cichk->holder_method());
f(cichk->holder_klass());
} else {
+ // Get Klass* or NULL (if value is -1) from GOT cell of virtual call PLT stub.
Metadata* ic_oop = ic->cached_metadata();
if (ic_oop != NULL) {
f(ic_oop);
}
}
+ } else if (iter.type() == relocInfo::static_call_type ||
+ iter.type() == relocInfo::opt_virtual_call_type){
+ // Check Method* in AOT c2i stub for other calls.
+ Metadata* meta = (Metadata*)nativeLoadGot_at(nativePltCall_at(iter.addr())->plt_c2i_stub())->data();
+ if (meta != NULL) {
+ f(meta);
+ }
}
}
}
@@ -332,7 +328,12 @@
st->print("%4d ", _aot_id); // print compilation number
st->print(" aot[%2d]", _heap->dso_id());
// Stubs have _method == NULL
- st->print(" %s", (_method == NULL ? _name : _method->name_and_sig_as_C_string()));
+ if (_method == NULL) {
+ st->print(" %s", _name);
+ } else {
+ ResourceMark m;
+ st->print(" %s", _method->name_and_sig_as_C_string());
+ }
if (Verbose) {
st->print(" entry at " INTPTR_FORMAT, p2i(_code));
}
--- a/hotspot/src/share/vm/aot/aotCompiledMethod.hpp Wed Jan 18 10:30:56 2017 -0500
+++ b/hotspot/src/share/vm/aot/aotCompiledMethod.hpp Wed Jan 18 14:36:54 2017 -0800
@@ -257,8 +257,6 @@
return (int) (*_state_adr);
}
- virtual void oops_do(OopClosure* f);
-
// inlined and non-virtual for AOTCodeHeap::oops_do
void do_oops(OopClosure* f) {
assert(_is_alive(), "");
--- a/hotspot/src/share/vm/runtime/deoptimization.cpp Wed Jan 18 10:30:56 2017 -0500
+++ b/hotspot/src/share/vm/runtime/deoptimization.cpp Wed Jan 18 14:36:54 2017 -0800
@@ -1596,9 +1596,9 @@
get_method_data(thread, profiled_method, create_if_missing);
// Log a message
- Events::log_deopt_message(thread, "Uncommon trap: reason=%s action=%s pc=" INTPTR_FORMAT " method=%s @ %d",
+ Events::log_deopt_message(thread, "Uncommon trap: reason=%s action=%s pc=" INTPTR_FORMAT " method=%s @ %d %s",
trap_reason_name(reason), trap_action_name(action), p2i(fr.pc()),
- trap_method->name_and_sig_as_C_string(), trap_bci);
+ trap_method->name_and_sig_as_C_string(), trap_bci, nm->compiler_name());
// Print a bunch of diagnostics, if requested.
if (TraceDeoptimization || LogCompilation) {