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

[Coleen Phillimore]

This looks good to me, there are a couple of questions.  Can you use 
/proc/self/maps instead of getting the tid?  Also there's a 'my' instead 
of 'by' in the comments.  Thank you for adding all the comments.

Coleen

Keith McGuigan wrote:
> Andrew Haley wrote:
>> On 03/04/2010 10:42 PM, Coleen Phillimore wrote:
>>  
>>> Hi,
>>> I'm also reviewing this change but I also had the same question about
>>> iostream.  I don't know the history either.  We have a similar function
>>> in os_linux.cpp called find_vma() which uses standard C file io.  You
>>> could rewrite get_stack_bounds() if there's a reason to.
>>>
>>> The other thing, || *jaxws/jaxws.properties *is checked into a 
>>> different
>>> repository (not the hotspot one).
>>>
>>> Also, I believe you need to add comments from the discussion in the
>>> emails in the new os_linux.cpp functions, because I for one will lose
>>> the email connection but it would be useful to preserve the reason for
>>> this change.
>>>
>>> Lastly, Andrew, do you need a sun employee to check this in?  I will do
>>> this once we resolve the issues above.
>>>     
>>
>> Done.  I also made the patch a little more robust: at the moment Linux
>> pthreads doesn't use growable mappings for thread stacks so there's no
>> need to munmap() the guard pages.  If ever pthreads does switch over to
>> using growable mappings I'm pretty sure this code will still work.
>>
>> Andrew.
>>
>>
>> http://cr.openjdk.java.net/~aph/6929067-jdk7-webrev-2/
>>   
>
> Looks good to me.  Thanks!
>
> -- 
> - Keith
>