Hi Jungwoo,
The DTrace probes are part of the serviceability support, bcc:ing gc-dev
and redirecting to serviceability-dev.
/Mikael
On 2015-02-14 02:21, Jungwoo Ha wrote:
I am not sure if DTraceAllocProbes is a live code, but I think this is a
bug.
dtrace_object_alloc has changed to receive size argument in JDK8.
This code only passes oop to dtrace_object_alloc. RDX has the size but
it needs to be saved.
I don't use DTrace, but it looks broken. If someone sponsor this is a
right fix, I'll create a webrev.
diff -r f06c7b654d63 src/cpu/x86/vm/templateTable_x86_32.cpp
--- a/src/cpu/x86/vm/templateTable_x86_32.cppThu Jul 31 09:58:53 2014 +0100
+++ b/src/cpu/x86/vm/templateTable_x86_32.cppFri Feb 13 17:14:57 2015 -0800
@@ -3288,6 +3288,7 @@
// The object is initialized before the header. If the object size is
// zero, go directly to the header initialization.
__ bind(initialize_object);
+ __ push(rdx); // save object size
__ decrement(rdx, sizeof(oopDesc));
__ jcc(Assembler::zero, initialize_header);
@@ -3328,13 +3329,14 @@
__ pop(rcx); // get saved klass back in the register.
}
__ store_klass(rax, rcx); // klass
+ __ pop(rdx); // restore object size to rdx
{
SkipIfEqual skip_if(_masm, &DTraceAllocProbes, 0);
// Trigger dtrace event for fastpath
__ push(atos);
__ call_VM_leaf(
- CAST_FROM_FN_PTR(address,
SharedRuntime::dtrace_object_alloc), rax);
+ CAST_FROM_FN_PTR(address,
SharedRuntime::dtrace_object_alloc), rax, rdx);
__ pop(atos);
}
diff -r f06c7b654d63 src/cpu/x86/vm/templateTable_x86_64.cpp
--- a/src/cpu/x86/vm/templateTable_x86_64.cppThu Jul 31 09:58:53 2014 +0100
+++ b/src/cpu/x86/vm/templateTable_x86_64.cppFri Feb 13 17:14:57 2015 -0800
@@ -3352,6 +3352,7 @@
// The object is initialized before the header. If the object size is
// zero, go directly to the header initialization.
__ bind(initialize_object);
+ __ movl(rbx, rdx); // save object size to rbx
__ decrementl(rdx, sizeof(oopDesc));
__ jcc(Assembler::zero, initialize_header);
@@ -3386,7 +3387,7 @@
// Trigger dtrace event for fastpath
__ push(atos); // save the return value
__ call_VM_leaf(
- CAST_FROM_FN_PTR(address,
SharedRuntime::dtrace_object_alloc), rax);
+ CAST_FROM_FN_PTR(address,
SharedRuntime::dtrace_object_alloc), rax, rbx);
__ pop(atos); // restore the return value
}
