RFR (L): 8024545: make develop and notproduct flag values available in product builds

[Christian Thalinger]

On Sep 12, 2013, at 5:24 PM, Vladimir Kozlov <vladimir.kozlov at oracle.com> wrote:

> On 9/12/13 5:11 PM, Christian Thalinger wrote:
>> 
>> On Sep 12, 2013, at 4:30 PM, Vladimir Kozlov <vladimir.kozlov at oracle.com> wrote:
>> 
>>> Christian,
>>> 
>>> Can you put _flags first to avoid padding between _addr and _value in 32-bit VM?
>> 
>> Yes, good point.
>> 
>>> 
>>> It would be nice enumerate flag's type and use int instead of strings:
>>> 
>>> enum {
>>>  bool_flag = 1,
>>>  intx_flag = 2,
>>> 
>>> + #define RUNTIME_PRODUCT_FLAG_STRUCT(     type, name, value, doc) { type##_flag, XSTR(name), &name,              VALUE(value), NOT_PRODUCT_ARG(doc) Flag::Flags(Flag::DEFAULT | Flag::KIND_PRODUCT) },
>> 
>> I was thinking of putting the type into the flags, too.  That would save another pointer word.  Should I give it a shot in this change or a separate one?
> 
> Do it in separate changes after you push this.
> And if you remove _type field later you don't need to move _flags now.
> So you can push your current changes as it is. They are good.

Thank you, Vladimir.  -- Chris

> 
> Thanks,
> Vladimir
> 
>> 
>> -- Chris
>> 
>>> 
>>> Thanks,
>>> Vladimir
>>> 
>>> On 9/12/13 9:58 AM, Christian Thalinger wrote:
>>>> 
>>>> On Sep 11, 2013, at 5:34 PM, David Holmes <david.holmes at oracle.com> wrote:
>>>> 
>>>>> Hi Chris,
>>>>> 
>>>>> There seems to be an awful lot "infrastructure" work needed to make something that sounds simple happen. :( All the changes to the scoping and the set/get methods tends to obscure the core change. My only suggestion here is that the "set" methods could perhaps factor this:
>>>>> 
>>>>> +   if (is_constant_in_binary()) {
>>>>> +     fatal(err_msg("flag is constant: %s", _name));
>>>>> 
>>>>> into a check_writable() method so that it isn't duplicated so much.
>>>> 
>>>> Good point.  I made that change:
>>>> 
>>>> http://cr.openjdk.java.net/~twisti/8024545/webrev/src/share/vm/runtime/globals.cpp.udiff.html
>>>> 
>>>>> 
>>>>> I also wonder whether a ConstFlag sub/superclass would simplify this at all?
>>>> 
>>>> Maybe it would but then we need more infrastructure to read the additional entries.  Might be a wash.  SA only knows about offsets in structs and the flags array is statically defined.
>>>> 
>>>>> 
>>>>> That aside I'm curious why the minimal VM size change is only 22K when client is 32K?
>>>> 
>>>> The 32-bit product build also contains the server compiler.
>>>> 
>>>> -- Chris
>>>> 
>>>>> 
>>>>> Thanks,
>>>>> David
>>>>> 
>>>>> On 11/09/2013 10:56 AM, Christian Thalinger wrote:
>>>>>> http://cr.openjdk.java.net/~twisti/8024545/webrev/
>>>>>> 
>>>>>> 8024545: make develop and notproduct flag values available in product builds
>>>>>> Reviewed-by:
>>>>>> 
>>>>>> Right now the internal flag table only contains flags which are defined in a product build. This does not include develop and notproduct flags. Sometimes it is useful to have access to these values for post-mortem core file analysis or to read these values for compiler settings for a Java-based compiler.
>>>>>> 
>>>>>> This change enables develop and notproduct flag values to be read by the serviceability agent. The binary size is increased by 42k for a 64-bit product build and by 32k for a 32-bit product build.
>>>>>> 
>>>>>> Before:
>>>>>> 
>>>>>> $ java -cp /java/re/jdk/8/latest/binaries/linux-x64/lib/sa-jdi.jar sun.jvm.hotspot.CLHSDB 9399
>>>>>> Attaching to process 9399, please wait...
>>>>>> hsdb> flags -nd
>>>>>> InitialHeapSize = 495006528 5
>>>>>> MaxHeapSize = 7920943104 5
>>>>>> UseCompressedKlassPointers = true 5
>>>>>> UseCompressedOops = true 5
>>>>>> UseParallelGC = true 5
>>>>>> hsdb> flags InlineMathNatives
>>>>>> Couldn't find flag: InlineMathNatives
>>>>>> 
>>>>>> After:
>>>>>> 
>>>>>> $ java -cp $JAVA_HOME/lib/sa-jdi.jar sun.jvm.hotspot.CLHSDB 3726
>>>>>> Attaching to process 3726, please wait...
>>>>>> hsdb> flags -nd
>>>>>> InitialHeapSize = 495006528 5
>>>>>> MaxHeapSize = 7920943104 5
>>>>>> UseCompressedKlassPointers = true 5
>>>>>> UseCompressedOops = true 5
>>>>>> UseParallelGC = true 5
>>>>>> hsdb> flags InlineMathNatives
>>>>>> InlineMathNatives = true 0
>>>>>> 
>>>>>> This patch has one behavioral difference; when printing flags with e.g. PrintFlagsFinal in a debug build it prints "develop" for develop flags:
>>>>>> 
>>>>>>     uintx AdaptiveSizePolicyGCTimeLimitThreshold    = 5               {develop}
>>>>>> 
>>>>>> The output for product builds is unchanged.
>>>>>> 
>>>> 
>>