[9] RFR (S) File leak in MemNotifyThread::start() in hotspot.src.os.linux.vm.os_linux.cpp

[David Holmes]

Looks good Chris - thanks for cleaning this up.

David

On 28/10/2014 4:33 PM, Chris Plummer wrote:
> Hi,
>
> Please review this change to fix a leaking fd.
>
> Summary: Fixed by removing all code related to LowMemoryProtection,
> which removed offending code.
>
> Webrev: http://cr.openjdk.java.net/~cjplummer/8043770/webrev.00/
> Bug: https://bugs.openjdk.java.net/browse/JDK-8043770
>
> Tested with jprt "-testset hotspot"
>
> Details: The offending code is there to support the
> -XX:+LowMemoryProtection flag, which relies on linux kernel support for
> /dev/mem_notify. Although the leak was easy to fix, I ran into an issue
> testing it. Apparently we have no devices that support /dev/mem_notify,
> and SQE is not testing this feature. It also turns out that in general
> /dev/mem_notify support has not been adopted, so LowMemoryProtection is
> of limited or no value, and in fact is a liability since we are not
> testing it. The decision was made to remove the support instead, thus
> also fixing the fd leak. This only affects builds with JAVASE_EMBEDDED
> enabled, so will not impact any JDK release.
>
> thanks,
>
> Chris