CSR Review: 8189423: Add option to disable stack overflow checking in primordial thread for use with JNI_CreateJavaJVM

[David Holmes]

On 17/10/2017 7:28 PM, Robbin Ehn wrote:
>> My understanding from prior discussion (ie when we fixed the 2MB stack 
>> limit) is that it doesn't work for them to use a new thread for the 
>> JVM. The change to support anything but unlimited stack size also 
>> helped (and the 8M limit when 'unlimited' is tolerable) but really 
>> they just want a simple way to say "please don't bother with stack 
>> guards, I can deal with that myself".
> 
> Is there a problem I'm not seeing to extends this to all attaching threads?
> E.g. -XX:+DisableAttachingThreadGuardPages (more useful option I would say)

Yes - that allows it to impact all of our launchers as well - not 
something I want to allow for. It opens the door for a myriad of bug 
reports if people use this flag without understanding it's consequences.

The aim here is to solve a specific problem, not introduce new ways to 
break things.

David

> Thanks, Robbin
> 
>>
>> This is intended to be a very simple, very specific proposal. I 
>> suppose it could be flagged as "experimental" if we wanted the 
>> flexibility to do something different later. But I don't see that 
>> being on the cards.
>>
>> Cheers,
>> David
>>
>>>
>>> Thanks Robbin
>>>
>>>>
>>>> Kind Regards, Thomas
>>>>
>>>>
>>>>
>>>> On Tue, Oct 17, 2017 at 9:22 AM, David Holmes <david.holmes at oracle.com>
>>>> wrote:
>>>>
>>>>> CSR: https://bugs.openjdk.java.net/browse/JDK-8189423
>>>>>
>>>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8189170
>>>>>
>>>>> Could I please have a reviewer for this CSR request so I can 
>>>>> fast-track it.
>>>>>
>>>>> Comments on the proposal are of course welcome.
>>>>>
>>>>> Thanks,
>>>>> David
>>>>>