[APPCDS] JDK-8236847: JDK built on machine with 4K pages refused to start on machine with 64k pages

[Ioi Lam]

On 1/9/20 12:47 AM, David Holmes wrote:
> On 9/01/2020 6:29 pm, Dmitry Samersoff wrote:
>> Hello Ioi,
>>
>> *Story*
>>
>> If you build JDK-14 with the changes for
>>
>>    JDK-8231610 Relocate the CDS archive if it cannot be mapped
>>    to the requested address
>>
>> on a machine with 4k pages (typical Jenkins machine) then move the
>> bundle to a huge server with 64k pages, it refuses to start with
>>
>> [0.015s][error][cds] Unable to map CDS archive --
>> os::vm_allocation_granularity() expected: 4096 actual: 65536
>>
>> *Question*
>>
>> I'm not sure if just removing an assert is the correct fix. What would
>> you recommend?
>
> I thought that failing to map the archive was a non-fatal error that 
> just results in falling back to not using CDS. Even in a debug build 
> this should not be an assertion unless perhaps the user has explicitly 
> requested CDS to be enabled.
>
Dmitry, are you running with -Xshare:on? If you use -Xshare:off (which 
is the default), when the CDS archive cannot be mapped, the JVM will 
continue execution.

Are you having problems running with the jtreg test cases? I can think 
of a way to fix this, so that CDS can continue to work under this 
circumstance, but I want to understand your scenarios more.

Thanks
- Ioi

>> Also @build-dev - is it possible to add configure option to disable
>> AppCDS archive generation?
>
> Already there I think: --disable-cds-archive
>
> Cheers,
> David
> -----
>
>
>>
>> -Dmitry\S
>>
>>
>>