Scott,

>From Randy...

I got the code change I made earlier today tested.  We can now make mmap
work if MAP_SHARED is used.  Essentially the call is reverted under the
covers to be a MAP_PRIVATE.  To enable the support, all you have to do is
load the kmod with the new fake_mmap_shared option.

Example:

insmod pvfs2.ko fake_mmap_shared=1

This will be in future releases, but if you want a patch let us know.

-boyd



On Tue, May 14, 2013 at 3:27 PM, Scott Roberts <[email protected]> wrote:

>  Hi Boyd,
>
>  The Java application we're trying to run doesn't use shared mmap.
>  That's a -very– old bug and I am surprised Sun/Oracle didn't fix it; maybe
> it breaks compatibility with an old application they wanted to support.
>
>  If you roll the fake out flag into the next version of OrangeFS we will
> give it a go.  No rush.  Our temporary workaround is to install the JDK on
> local disk on each compute node.
>
>  Thanks,
> --Scott
>
>   From: Boyd Wilson <[email protected]>
> Date: Tuesday, May 14, 2013 1:50 PM
> To: Scott Roberts <[email protected]>
> Cc: PVFS2-Users <[email protected]>
> Subject: Re: [Pvfs2-users] Executing the Java binary on OrangeFS
>
>   This is caused by the JVM requiring shared mmap, when the java app does
> not even need it and the current KM for OrangeFS does not support shared
> MMAP.  We have talked about implementing it, but that would take a while,
> we also have discussed just putting in a fake out flag for the KM.   Do you
> know if the java app you are trying to use actually uses shared mmap or
> not?  (if not we can look at turning around the fake out flag pretty
> quickly).   This is not limited to JVM , some other apps do the same thing
> (very very few actually use shared mmap).
>
>  There is also this older java bug report (requesting the JVM not do
> this), its here:
> http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7085890
>
>  thanks,
> -boyd
>
>
> On Tue, May 14, 2013 at 12:30 PM, Scott Roberts <[email protected]> wrote:
>
>>  Good afternoon,
>>
>>  Has anyone encountered issues executing applications directly from an
>> OrangeFS mount?  Most applications like Python, Perl, &c. work fine.  I
>> untarred the 64-bit version of Java 7 to the location /export/ofs/apps/src
>> with no errors.   However, executing Java throws this error:
>>
>>  ./java -version
>> mmap failed for CEN and END part of zip file
>> Error occurred during initialization of VM
>> java/lang/ClassNotFoundException: error in opening JAR file
>> /export/ofs/apps/src/jdk1.7.0_21/jre/lib/rt.jar
>>
>>  Any ideas?
>>
>>  Cheers,
>> --Scott
>>
>> _______________________________________________
>> Pvfs2-users mailing list
>> [email protected]
>> http://www.beowulf-underground.org/mailman/listinfo/pvfs2-users
>>
>>
>
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