Well, I have noticed that when a process is waiting for communication from another process the reported CPU usage remains around 100%. Is that what you mean? I haven't explored whether these processes give way to other active processes under the linux scheduler, nor whether I should expect anything different. This has been with 1.2.3 and 1.2.4.
On Tue, 2008-01-22 at 16:48 +1100, Graham Jenkins wrote: > 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") >
