| Summary: | mm: compaction: Ensure that the compaction free scanner does not move to the next zone | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux 6 | Reporter: | Andrea Arcangeli <aarcange> |
| Component: | kernel | Assignee: | Andrea Arcangeli <aarcange> |
| Status: | CLOSED ERRATA | QA Contact: | Caspar Zhang <czhang> |
| Severity: | medium | Docs Contact: | |
| Priority: | medium | ||
| Version: | 6.2 | CC: | czhang, juzhang, kzhang, qcai, tburke |
| Target Milestone: | rc | ||
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | kernel-2.6.32-169.el6 | Doc Type: | Bug Fix |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2011-12-06 13:38:31 UTC | Type: | --- |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
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 |
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