Request for approval: 6929067: Stack guard pages should be removed when thread is detached

[David Holmes]

Andrew, Coleen,

Andrew Haley said the following on 03/12/10 19:44:
> On 03/11/2010 09:06 PM, Coleen Phillimore wrote:
>> I've added the test to the changeset and a script to run in our harness.
>>
>> Also in os_linux.cpp, I changed the SYS_gettid call to go through our
>> os::Linux::gettid() because on at least one linux, syscall() returns a
>> long int which gets a compilation warning with %d.
>>
>> open webrev at http://cr.openjdk.java.net/~coleenp/6929067/
>> bug link at http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6929067
>>
>> Andrew, please have a look since you're the contributor.
> 
> That's OK, but you don't need SYS_gettid.
> Please look at http://cr.openjdk.java.net/~aph/6929067-jdk7-webrev-4/hotspot.patch
> I changed to "/proc/self/maps", as you requested.  I think this is better.

It looks like the use of /proc/self/maps can be a thread termination 
bottleneck. Is there a way to determine whether this functionality is 
needed for the current thread without actually reading the map file?

Thanks,
David Holmes