trying to fix 6843484 (os::commit_memory() failures are not handled properly on linux)

[Omair Majid]

Hi,

I have been trying to fix 6843484. The bug relies on exact behaviour of 
mmap(2) on linux. I have asked for help from kernel developers and they 
have suggested that this is not a bug. Just so that I am clear, here is 
what I understood from the bug report:

The bug happens if hotspot does
(1) mmap(ADDR,..., MAP_NORESERVE,...) = succeeds
followed by
(2) mmap(ADDR, .....) = fails
in which case the map from (1) is lost.

The linux kernel developers have suggested (and this is what I also 
observed in my testing) that the map is, in fact, preserved. What should 
be the next step? Is there a test case that demonstrates the behaviour 
indicated in the bug report?

Thanks,
Omair