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From: "Amit K. Arora" <aarora@linux.vnet.ibm.com>
To: linux-numa@vger.kernel.org
Cc: aarora@linux.vnet.ibm.com
Subject: [PATCH 0/2] non-contiguous NUMA nodes handling in numactl and libnuma
Date: Mon, 2 Mar 2009 18:35:46 +0530	[thread overview]
Message-ID: <20090302130546.GA31167@amitarora.in.ibm.com> (raw)

PROBLEM: If the NUMA nodes in a system are not contiguous, numactl shows
incorrect output. Here is an example from one such system:

------------------------------------------------------
# ls /sys/devices/system/node
has_cpu  has_normal_memory  node0  node1  node4  node5  online  possible
# numactl --hardware
available: 6 nodes (0-5)
node 0 cpus: 0 1 2 3
node 0 size: 15232 MB
node 0 free: 2265 MB
node 1 cpus: 4 5 6 7
node 1 size: 16256 MB
node 1 free: 3108 MB
libnuma: Warning: /sys not mounted or invalid. Assuming one node: No
such file or directory
node 2 cpus:
node 2 size: <not available>
node 2 free: <not available>
node 3 cpus:
node 3 size: <not available>
node 3 free: <not available>
node 4 cpus: 8 9 10 11
node 4 size: 16000 MB
node 4 free: 9292 MB
node 5 cpus: 12 13 14 15
node 5 size: 16128 MB
node 5 free: 9479 MB
node distances:
node   0   1   2   3   4   5 
  0:  10  20  20  20  20  10 
  1:  20  10  20  20   0   0 
  2:   0   0   0   0   0   0 
  3:   0   0   0   0   0   0 
  4:   0   0   0  1112145  1024  2607344 
  5:  1024  2607344  1024  2607344   0   0 
------------------------------------------------------


As we see above, there are three problems with above output:
o it is showing wrong number of available nodes
	Actually there are 4 nodes available, but it says "6".
o it tries to access information for non-exsistent nodes from /sys
	Thus displaying a wrong warning message too
o the NUMA distances it shows above are clearly incorrect.

Following two patches fixes these problems:
1) numactl-handle-NUMA-dist-properly.patch
2) numactl-ignore-nonavailable-nodes.patch


--
Regards,
Amit Arora

             reply	other threads:[~2009-03-02 13:05 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-03-02 13:05 Amit K. Arora [this message]
2009-03-02 13:19 ` [PATCH 1/2] handle NUMA distances properly for non-contiguous nodes Amit K. Arora
2009-03-02 13:23 ` [PATCH 2/2] ignore unavailable NUMA nodes Amit K. Arora
2009-03-02 13:27 ` Results after applying the patch Amit K. Arora
2009-03-02 13:58 ` [PATCH 0/2] non-contiguous NUMA nodes handling in numactl and libnuma Cliff Wickman
2009-03-09 13:17   ` [PATCH] distance table for non-contiguous NUMA nodes Amit K. Arora

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