RFR (M) 8139551: Scalability problem with redefinition - multiple code cache walks

[coleen.phillimore at oracle.com]

On 2/4/19 5:30 PM, serguei.spitsyn at oracle.com wrote:
> Hi Coleen,
>
> Looks good in general.
>
> Just a couple minor comments below.
>
> I hope, you will update the copyright years before the push.

Hi Serguei,  Thanks for reviewing this.

Yes, I update the copyright years in my commit script.
>
>
> http://cr.openjdk.java.net/~coleenp/2019/8139551.01/webrev/test/hotspot/jtreg/runtime/RedefineTests/TestMultipleClasses.java.html
>
>   Nice test!
>    37 import java.lang.reflect.*;
>    38 import jdk.test.lib.compiler.InMemoryJavaCompiler;
>    39 import java.lang.instrument.*;
>   The imports above can be re-ordered.

Alphabetically?
>
>    44         return new String("public class B" + count + " {" +
>    45                 "   public static void compiledMethod() { " +
>    46                 "       try{" +
>    47                 "          Thread.currentThread().sleep(1); " +
>    48                 "       } catch(InterruptedException ie) {" +
>    49                 "       }" +
>    50                 "   }" +
>    51                 "}");
>   Not clear, why sleep is needed here.
>

Yes, the sleep was there so that the compiler didn't optimize away the 
function.  I didn't put a print because it would print too many times.

Thanks,
Coleen
>
> Thanks,
> Serguei
>
>
> On 2/4/19 12:34, serguei.spitsyn at oracle.com wrote:
>> Added the serviceability-dev back.
>>
>> Thanks,
>> Serguei
>>
>>
>> On 2/4/19 07:18, coleen.phillimore at oracle.com wrote:
>>>
>>> open webrev at 
>>> http://cr.openjdk.java.net/~coleenp/2019/8139551.01/webrev
>>> bug link https://bugs.openjdk.java.net/browse/JDK-8139551
>>>
>>> The links.
>>> Thanks,
>>> Coleen
>>>
>>> On 2/4/19 10:08 AM, coleen.phillimore at oracle.com wrote:
>>>> Summary: Walk code cache and deoptimize once per redefinition.*
>>>>
>>>> *This change touches the AOT and code cache code.  I tried to 
>>>> describe it in the comments in the RFE.  Basically, for 
>>>> redefinition, we walk the code cache per class redefined in order 
>>>> to find evol_method dependencies, then deoptimize if we find them, 
>>>> and then walk the code cache again to mark the deoptimized nmethods 
>>>> as not_entrant.
>>>>
>>>> I replaced this with only marking any nmethods for the class's 
>>>> methods to deoptimize (following InstanceKlass::_methods), also 
>>>> marking aot methods dependent on the class, and then doing the code 
>>>> cache walk to follow the evol_method dependencies at the end of 
>>>> redefinition for all the classes.   The new code uses the 
>>>> Method::is_old() flag rather than comparing each method in the 
>>>> InstanceKlass.  Then deoptimization and marking not_entrant is done 
>>>> once at the end of the redefinition as well.
>>>>
>>>> Tested with tier1-6, all the redefinition tests locally:
>>>>
>>>> make test TEST=open/test/hotspot/jtreg/vmTestbase/nsk/jvmti 
>>>> >&jvmti.out
>>>> make test TEST=open/test/hotspot/jtreg/vmTestbase/nsk/jdi >&jdi.out
>>>> make test TEST=open/test/hotspot/jtreg/runtime/RedefineTests 
>>>> >&redefine.out
>>>> make test TEST=open/test/jdk/java/lang/instrument >&instrument.out
>>>>
>>>> new test, and JMH test (see CR for results).
>>>>
>>>> Thanks,
>>>> Coleen
>>>>
>>>>
>>>
>>
>

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