diff --git a/doc/man/man5/slurm.conf.5 b/doc/man/man5/slurm.conf.5 index c6a7ae5fe97927b2112c84e952aabc04109904c7..7682aebfb43d7449e0cbb05aca80e545a91ff271 100644 --- a/doc/man/man5/slurm.conf.5 +++ b/doc/man/man5/slurm.conf.5 @@ -1303,29 +1303,33 @@ The following values are supported for \fBSelectType=select/cons_res\fR: \fBCR_CPU\fR CPUs are consumable resources. There is no notion of sockets, cores or threads; -do not define those values in the node specification. +do not define those values in the node specification. If these +are defined, unexpected results will happen when hyper\-threading +is enabled Procs= should be used instead. On a multi\-core system, each core will be considered a CPU. -On a multi\-core and hyperthreaded system, each thread will be +On a multi\-core and hyper\-threaded system, each thread will be considered a CPU. On single\-core systems, each CPUs will be considered a CPU. .TP \fBCR_CPU_Memory\fR CPUs and memory are consumable resources. There is no notion of sockets, cores or threads; -do not define those values in the node specification. +do not define those values in the node specification. If these +are defined, unexpected results will happen when hyper\-threading +is enabled Procs= should be used instead. Setting a value for \fBDefMemPerCPU\fR is strongly recommended. .TP \fBCR_Core\fR Cores are consumable resources. On nodes with hyper\-threads, each thread is counted as a CPU to satisfy a job's resource requirement, but multiple jobs are not -allocated threads on the same core. +allocated threads on the same core. .TP \fBCR_Core_Memory\fR Cores and memory are consumable resources. On nodes with hyper\-threads, each thread is counted as a CPU to satisfy a job's resource requirement, but multiple jobs are not -allocated threads on the same core. +allocated threads on the same core. Setting a value for \fBDefMemPerCPU\fR is strongly recommended. .TP \fBCR_Socket\fR @@ -1961,7 +1965,10 @@ resolution of a core. If your system is configured with more than one thread per core, execution of a different job on each thread is not supported. A job can execute a one task per thread from within one job step or -execute a distinct job step on each of the threads. +execute a distinct job step on each of the threads. +Note also if you are running with more than 1 thread per core and running +the select/cons_res plugin you will want to set the SelectTypeParameters +variable to something other than CR_CPU to avoid unexpected results. The default value is 1. .TP