review request (S) - 8014611: reserve_and_align() assumptions

[John Coomes]

Daniel D. Daugherty (daniel.daugherty at oracle.com) wrote:
> On 5/15/13 10:59 AM, John Coomes wrote:
> > Please review this change for hs24:
> >
> > 	8014611: reserve_and_align() assumptions are invalid on windows
> >
> > 	http://cr.openjdk.java.net/~jcoomes/8014611-reserve-and-align/
> 
> Thumbs up!

Thanks for looking at it.

> src/share/vm/runtime/os.hpp
>      No comments.
> 
> src/os/posix/vm/os_posix.cpp
>      No comments.
> 
> src/os/windows/vm/os_windows.cpp
>      +bool os::release_partial_region(char* addr, size_t bytes) {
>      + return uncommit_memory(addr, bytes);
>      +}
> 
>      So on Win* we 'uncommit' the memory instead of releasing it which
>      gets us partial resource relief, i.e., no backing store. Do I
>      have this right?

Exactly right.  In the single anticipated use of this code, the
uncommitted space should be small (< 256K).

-John

> src/share/vm/runtime/virtualspace.hpp
>      No comments.
> 
> src/share/vm/runtime/virtualspace.cpp
>      No comments.
> 
> Dan
> 
> 
> >
> > The webrev has more info about the problem and the fix.
> >
> > -John
>