[lustre-discuss] Lustre 2.10.1 + RHEL7 Page Allocation Failures

[Jones, Peter A]

Charles

That ticket is completely open so you do have access to everything. As I understand it the options are to either use the latest MOFED update rather than relying on the in-kernel OFED (which I believe is the advise usually provided by Mellanox anyway) or else apply the kernel patch Andreas has created that is referenced in the ticket.

Peter

On 2017-11-29, 2:50 AM, "lustre-discuss on behalf of Charles A Taylor" <lustre-discuss-bounces at lists.lustre.org<mailto:lustre-discuss-bounces at lists.lustre.org> on behalf of chasman at ufl.edu<mailto:chasman at ufl.edu>> wrote:


Hi All,

We recently upgraded from Lustre 2.5.3.90 on EL6 to 2.10.1 on EL7 (details below) but have hit what looks like LU-10133 (order 8 page allocation failures).

We don’t have access to look at the JIRA ticket in more detail but from what we can tell the the fix is to change from vmalloc() to vmalloc_array() in the mlx4 drivers.  However, the vmalloc_array() infrastructure is in an upstream (far upstream) kernel so I’m not sure when we’ll see that fix.

While this may not be a Lustre issue directly, I know we can’t be the only Lustre site running 2.10.1 over IB on Mellanox ConnectX-3 HCAs.  So far we have tried increasing vm.min_free_kbytes to 8GB but that does not help.  Zone_reclaim_mode is disabled (for other reasons that may not be valid under EL7) but order 8 chunks get depleted on both NUMA nodes so I’m not sure that is the answer either (though we have not tried it yet).

[root at ufrcmds1 ~]# cat /proc/buddyinfo
Node 0, zone      DMA      1      0      0      0      2      1      1      0      1      1      3
Node 0, zone    DMA32   1554  13496  11481   5108    150      0      0      0      0      0      0
Node 0, zone   Normal 114119 208080  78468  35679   6215    690      0      0      0      0      0
Node 1, zone   Normal  81295 184795 106942  38818   4485    293   1653      0      0      0      0

I’m wondering if other sites are hitting this and, if so, what are you doing to work around the issue on your OSSs.

Regards,

Charles Taylor
UF Research Computing


Some Details:
-------------------
OS: RHEL 7.4 (Linux ufrcoss28.ufhpc 3.10.0-693.2.2.el7_lustre.x86_64)
Lustre: 2.10.1 (lustre-2.10.1-1.el7.x86_64)
Clients: ~1400 (still running 2.5.3.90 but we are in the process of upgrading)
Servers: 10 HA OSS pairs (20 OSSs)
   128 GB RAM
   6 OSTs (8+2 RAID-6) per OSS
   Mellanox ConnectX-3 IB/VPI HCAs
   RedHat Native IB Stack (i.e. not MOFED)
   mlx4_core driver:
      filename:       /lib/modules/3.10.0-693.2.2.el7_lustre.x86_64/kernel/drivers/net/ethernet/mellanox/mlx4/mlx4_core.ko.xz
      version:        2.2-1
      license:        Dual BSD/GPL
      description:    Mellanox ConnectX HCA low-level driver
      author:         Roland Dreier
      rhelversion:    7.4
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