Hi,

I tried to find out the culprit. Its seems that call to vma_merge in mbind_range, which has been added to bound the number of vma's. When I tried disabling the call to vma_merge, the problem didn't reproduce using the attached test program. Also, it seems that the initial implementation of do_mbind didn't have merge feature, and it worked fine back then. 2.6.27 doesn't have vma_merge and it works fine with this kernel.

Lokesh

Since RHEL 6.2 External Beta has begun, and this bug remains
unresolved, it has been rejected as it is not proposed as
exception or blocker.

Red Hat invites you to ask your support representative to
propose this request, if appropriate and relevant, in the
next release of Red Hat Enterprise Linux.

*** Bug 752867 has been marked as a duplicate of this bug. ***

Created attachment 550879 [details]
strace output of mmap, munmap, and mbind calls with OpenCL stderr prints (prefixed by "DAB") of allocation and error information.

------- Comment From tpnoonan.com 2012-01-06 09:34 EDT-------
can we now request for 6.2.z?

Hello IBM,
Please provide a client impact statement for the Z request.

Thank You
Joe Kachuck

This request was evaluated by Red Hat Product Management for inclusion
in a Red Hat Enterprise Linux maintenance release. Product Management has 
requested further review of this request by Red Hat Engineering, for potential
inclusion in a Red Hat Enterprise Linux Update release for currently deployed 
products. This request is not yet committed for inclusion in an Update release.

------- Comment From tpnoonan.com 2012-01-29 20:45 EDT-------
hi red hat, justification for z-stream: This seems like a pretty serious and fundamental problem given the
pervasiveness of multi-core processors and multi-threaded applications.  We
won't be able to announce support on RHEL 6.x for our SW* (which is planned to
be released in Jan 2012)  if a patch is not publicly available. *It is OpenCL for Power.  OpenCL??? is the first open, royalty-free standard for
cross-platform, parallel programming of modern processors found in personal
computers, servers and handheld/embedded devices. OpenCL (Open Computing
Language) greatly improves speed and responsiveness for a wide spectrum of
applications in numerous market categories from gaming and entertainment to
scientific and medical software.

For more information on OpenCL, see

http://en.wikipedia.org/wiki/OpenCL
http://www.khronos.org/

------- Comment From tpnoonan.com 2012-01-30 11:22 EDT-------
regression, works in 6.0 fails in 6.1/6.2

Patch(es) available on kernel-2.6.32-229.el6

Hello,
This bug has been copied as 6.2 z-stream (EUS) bug #802379

Thank You
Joe Kachuck

be released in Jan 2012)  if a patch is not publicly available. *It is OpenCL for Power.  OpenCL? is the first open, royalty-free standard for

    Technical note added. If any revisions are required, please edit the "Technical Notes" field
    accordingly. All revisions will be proofread by the Engineering Content Services team.
    
    New Contents:
An anomaly in the memory map created by the mbind() function caused a segmentation fault in Hotspot Java Virtual Machines with the NUMA-aware Parallel Scavenge garbage collector. A backported upstream patch that fixes mbind() has been provided and the crashes no longer occur in the described scenario.

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

http://rhn.redhat.com/errata/RHSA-2012-0862.html

Removing external tracker bug with the id 'https://access.redhat.com/site/solutions/352973' as it is not valid for this tracker