[SERVER-13900] Numactl use in Ubuntu upstart script should check the number of nodes Created: 11/May/14  Updated: 07/Apr/23  Resolved: 12/May/14

Status: Closed
Project: Core Server
Component/s: Packaging
Affects Version/s: 2.6.1
Fix Version/s: None

Type: Improvement Priority: Minor - P4
Reporter: Frédéric G. MARAND Assignee: Unassigned
Resolution: Done Votes: 0
Labels: None
Remaining Estimate: Not Specified
Time Spent: Not Specified
Original Estimate: Not Specified
Environment:

Ubuntu


Backwards Compatibility: Fully Compatible
Participants:

 Description   

Since SERVER-7268, numactl is checked for availability and used if found working.

However, the command may be available and working on a SMP/UMA system, on which the number of nodes in the NUMA sense will be one, in which case there is no point in using it : the script should detect that case and fall back to a normal launch when there is only one node.



 Comments   
Comment by Matt Kangas [ 12/May/14 ]

fgm, I tested your scenario on an Ubuntu 10.04 LTS VM. Here is the base NUMA config:

kangas@orion:~$ numactl --show
policy: default
preferred node: current
physcpubind: 0 1 2 3 4 5 6 7
cpubind: 0
nodebind: 0
membind: 0

Single NUMA node, 8 cores.

Now let's run "numactl --interleave=all" to see it has any effect. With exactly one NUMA node to bind against, it should have no material effect.

kangas@orion:~$ numactl --interleave=all -- numactl --show
policy: interleave
preferred node: 0 (interleave next)
interleavemask: 0
interleavenode: 0
physcpubind: 0 1 2 3 4 5 6 7
cpubind: 0
nodebind: 0
membind: 0

"policy" has changed but all other values are precisely the same. "numactl --interleave=all" effectively no-ops in this scenario. So there is no need to complicate the startup script with a different code path that will require separate testing.

Generated at Thu Feb 08 03:33:15 UTC 2024 using Jira 9.7.1#970001-sha1:2222b88b221c4928ef0de3161136cc90c8356a66.