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Description of problem: with CONFIG_NUMA=n and memcg and transparent hugepage enabled, there could be a double free later leading to VM_BUG_ON in get_page(). How reproducible: only reproducible on x86-64 with CONFIG_NUMA=n but all x86-64 kernels with transparent hugepage support enabled should have CONFIG_NUMA=y. So it shouldn't be reproducible. Steps to Reproduce: 1. build RHEL6 with CONFIG_NUMA=n, CONFIG_TRANSPARENT_HUGEPAGE=y 2. enable memcg 3. exaust the memcg limit from regular allocations and swapout 4. swapin 5. after swapin khugepaged will fail the compaction with memcg exausted -> bug Actual results: double free and oops Expected results: khugepaged should fail silently without double free or oopses Additional info: It shouldn't be reproducible in RHEL6/6.1 because all x86-64 kernels have CONFIG_NUMA=y.
Fix posted to rhkernel-list with Message-ID: <20110315175252.GQ10696>.
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.
Patch(es) available on kernel-2.6.32-128.el6
An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on therefore solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHSA-2011-0542.html