We've observed an excessive use of CPU system resources with OpenMPI
1.2.4 using TCP connections only on our SL5 x86_64 Cluster. Typically,
for a simple Canonical Ring Program, we're seeing between 30 and 70%
system usage.
Has anybody else noticed this sort of behaviour?
And does anybody have some suggestions for resolving the issue?
Present values we have are:
--
ompi_info --param btl tcp |grep MCA
MCA btl: parameter "btl_base_debug" (current value: "0")
MCA btl: parameter "btl" (current value: <none>)
MCA btl: parameter "btl_base_verbose" (current value: "0")
MCA btl: parameter "btl_tcp_if_include" (current value:
"eth0")
MCA btl: parameter "btl_tcp_if_exclude" (current value:
"lo")
MCA btl: parameter "btl_tcp_free_list_num" (current
value: "8")
MCA btl: parameter "btl_tcp_free_list_max" (current
value: "-1")
MCA btl: parameter "btl_tcp_free_list_inc" (current
value: "32")
MCA btl: parameter "btl_tcp_sndbuf" (current value:
"131072")
MCA btl: parameter "btl_tcp_rcvbuf" (current value:
"131072")
MCA btl: parameter "btl_tcp_endpoint_cache" (current
value: "30720")
MCA btl: parameter "btl_tcp_exclusivity" (current
value: "0")
MCA btl: parameter "btl_tcp_eager_limit" (current
value: "65536")
MCA btl: parameter "btl_tcp_min_send_size" (current
value: "65536")
MCA btl: parameter "btl_tcp_max_send_size" (current
value: "131072")
MCA btl: parameter "btl_tcp_min_rdma_size" (current
value: "131072")
MCA btl: parameter "btl_tcp_max_rdma_size" (current
value: "2147483647")
MCA btl: parameter "btl_tcp_flags" (current value: "122")
MCA btl: parameter "btl_tcp_priority" (current value: "0")
MCA btl: parameter "btl_base_warn_component_unused"
(current value: "1")
--
Graham Jenkins
Senior Software Specialist, eResearch
Monash University
Email: graham.jenk...@its.monash.edu.au
Tel: +613 9905-5942 (office) +614 4850-2491 (mobile)
