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Description of problem: nr_isolated_file of zone DMA becomes fixed 1 and nr_isolated_file or zone NORMAL becomes fixed -1 How reproducible: not reproducible with CONFIG_SMP=y, and so far only reproduced on x86 32bit (maybe because of lack of ZONE_DMA32 with <4GB of ram and HIGHMEM4G=y [64G=n]). Steps to Reproduce: 1. run a lot of SLUB order 3 allocations or THP allocations invoking compaction (better on 32bit but THP isn't available on 32bit kernels in RHEL6 so the kernel should be built with SLUB, alternatively increasing /sys/kernel/mm/hugepages-*/nr_hugepages and decreasing it in a loop may allow to reproduce it on 32bit x86) with CONFIG_SMP=n 2. grep nr_isolated /proc/zoneinfo 3. Actual results: eventually the DMA zone nr_isolated_file should get fixed to 1 the NORMAL zone will go to -1 (4294967295). The VM may hang too because the -1 value of the normal zone will hang it in too_many_isolated(). Expected results: No hang and nr_isolated_* always >= 0 in a idle system (not -1). Additional info: During hang: egrep 'Node|nr_isolated' /proc/zoneinfo Node 0, zone DMA nr_isolated_anon 0 nr_isolated_file 1 Node 0, zone Normal nr_isolated_anon 0 nr_isolated_file 4294967295 Node 0, zone HighMem nr_isolated_anon 0 nr_isolated_file 0
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-2.6.32-169.el6
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-2011-1530.html