Request for reviews (XS): 6869822: assert(Universe::narrow_oop_shift() == 0,"use unscaled narrow oop")

[Tom Rodriguez]

looks good.

tom

On Aug 11, 2009, at 9:23 AM, Vladimir Kozlov wrote:

>
> http://cr.openjdk.java.net/~kvn/6869822/webrev.00
>
> Fixed 6869822: assert(Universe::narrow_oop_shift() == 0,"use  
> unscaled narrow oop")
>
> Problem:
> The test uses -XX:HeapBaseMinAddress=32g flag to force heap allocation
> above 32g and get compressed oops with non zero base.
> In such case the finction Universe::preferred_heap_base() sets
> narrow_oop_shift to 3 and returns 0 as requested heap address.
> But with 0 requested address (default memory address request) OS  
> still may
> allocate small heap bellow 4gb. And this will trigger the assert.
>
> Solution:
> Replace the assert with narrow_oop_shift set to 0.
> Also use specified on command line HeapBaseMinAddress value as
> heap base address for the first (from three) request.
>
> Reviewed by:
>
> Fix verified (y/n): y, bug's tests
>
> Other testing:
> JPRT
>