RFR: Check BS type in immByteMapBase predicate

[Aleksey Shipilev]

On 12/05/2017 01:11 PM, Roman Kennke wrote:
> Am 05.12.2017 um 11:55 schrieb Aleksey Shipilev:
>> On 12/05/2017 11:50 AM, Roman Kennke wrote:
>>  What would happen if code uses that operand, but new predicate mismatches it (e.g. in Shenandoah)?
> It cannot be used in Shenandoah because we don't  use the CardTableModRefBS. Checking for the BS
> type seems the safest way to prevent the bug.

Oh, okay.

>>> I intend to push backports of this to 9 and 8 too. Do I need extra reviews for those?
>> Since this is not 9- or 8u-specific, I think you just push to sh/jdk10, and then regular backports
>> process handles the propagation to sh/jdk9 and sh/jdk10.
> 
> Ok.

This is okay to go to sh/jdk10. Can you give aarch64 maintainers a heads-up about this fix? It
probably warrants the fix in upstream for other collector's benefit, like Epsilon.

Thanks,
-Aleksey