knl.conf

Section: Slurm Configuration File (5)
Updated: Slurm Configuration File
Index

NAME

knl.conf - Slurm configuration file for Intel Knights Landing processor.

DESCRIPTION

This ASCII file which describes configuration information for Intel Knights Landing processors and its name may depend upon the NodeFeatures plugin configured in Slurm. For example, on Cray systems NodeFeatures should be configured to "knl_cray" and its configuration file will be read from "knl_cray.conf". The file will always be located in the same directory as the slurm.conf. This file is optional.

Parameter names are case insensitive. Any text following a "#" in the configuration file is treated as a comment through the end of that line. Changes to the configuration file take effect upon restart of Slurm daemons, daemon receipt of the SIGHUP signal, or execution of the command "scontrol reconfigure" unless otherwise noted.

The overall configuration parameters available include:

AllowMCDRAM

Specify the MCDRAM modes which jobs are allowed to use. This may be a subset of MCDRAM modes supported by the node. If not specified, all MCDRAM modes supported by the node are available for use. The comma separated list of allowed MCDRAM modes may include any of the modes listed below.

cache: All of MCDRAM to be used as cache.

equal: MCDRAM to be used partly as cache and partly combined with primary memory.

flat: MCDRAM to be combined with primary memory into a "flat" memory space.

AllowNUMA

Specify the NUMA modes which jobs are allowed to use. This may be a subset of NUMA modes supported by the node. If not specified, all NUMA modes supported by the node are available for use. The comma separated list of allowed NUMA modes may include any of the modes listed below. Note that Slurm can only support homogeneous nodes (e.g. the same number of cores per NUMA node). KNL scn4 and quad modes are not homogeneous, but each NUMA mode will have either 16 or 18 cores. This will result in Slurm using the lower core count and finding a total of 256 threads rather than 272 threads and setting the node to a DOWN state. Therefore it is recommended that snc4 and quad mode not be allowed at this time.

a2a: All to all

snc2: Sub-NUMA cluster 2

snc4: Sub-NUMA cluster 4

hemi: Hemisphere

quad: Quadrant

AllowUserBoot

A comma-delimited list of users allowed to modify a node's MCDRAM or NUMA state. If not specified then any user can change a node's state and reboot it.

BootTime

Estimated time to reboot a node in seconds. Used as a basis for optimizing scheduling decisions. The default value is 300 seconds (5 minutes) for the "knl_generic" plugin and 2700 seconds (45 minutes) for the "knl_cray" plugin.

CapmcPath

Fully qualified path to the capmc program. The default value is "/opt/cray/capmc/default/bin/capmc". This parameter is used only by the "knl_cray" plugin.

CapmcPollFreq

Time interval between when the capmc program should poll for node state changes, in seconds. The default value is 45 seconds. This parameter is used only by the "knl_cray" plugin.

CapmcRetries

Number of times to retry failed operations of the capmc program. Default value is 4.

CapmcTimeout

Time limit for the capmc program to return status information milliseconds. The default value is 60000 milliseconds and the minimum value is 1000 milliseconds. This parameter is used by the "knl_cray" plugin, plus the capmc_suspend and capmc_resume programs used for suspending and resuming nodes.

CnselectPath

Fully qualified path to the cnselect program. The default value is "/opt/cray/sdb/default/bin/cnselect". This parameter is used only by the "knl_cray" plugin.

DefaultMCDRAM

Specify the default MCDRAM modes for job's which do not specify a value. This is only used when a node is booted and the job which has been allocated the node does not specify a desired MCDRAM mode. The value can include one of the possible values identified with the AllowMCDRAM configuration parameter above. The default value is "cache".

DefaultNUMA

Specify the default NUMA modes for job's which do not specify a value. This is only used when a node is booted and the job which has been allocated the node does not specify a desired NUMA mode. The value can include one of the possible values identified with the AllowNUMA configuration parameter above. The default value is "a2a".

Force

If set to a non-zero value then load the node_features/generic plugin even on non-KNL nodes. Used primarily for testing purposes.

LogFile

Fully qualified path to a log file. The default value is SlurmctldLogFile from the slurm.conf configuration file. This is option is used only by the campc_suspend and campc_resume programs (which power down and reboot nodes in the appropriate configuration).

McPath

Fully qualified path to memory controller device file directory. Children of this directory with names of the form "mc#/csrow#/ue_count" (i.e. the count of unrecoverable memory errors) will be monitored for non-zero values. If such errors are detected, the node will be set to a DOWN state and the slurmd daemon will shutdown. The default value is "/sys/devices/system/edac/mc". See also UmeCheckInterval.

NumaCpuBind

Contains pairs of NUMA modes and the CpuBind mode to set a node to for that mode. Any compute node found with or set to the specified NUMA mode will have that node's CpuBind field set to the configured value. The NUMA node will be followed by an equal sign the desired CpuBind mode for that NUMA mode. Multiple NUMA mode and CpuBind modes should be in a semicolon separated list. By default changes to a node's NUMA mode will not effect that node's CpuBind mode. See the example below.

SyscfgPath

Fully qualified path to Intel's syscfg program, which identifies current KNL configuration by viewing BIOS settings. If not defined, the current BIOS setting will not be available. The default value is "/usr/bin/syscfg". This parameter is used only by the "knl_generic" plugin.

SyscfgTimeout

Timeout for syscfg program in milliseconds. Default value is 1000 milliseconds. For Dell KNL systems, experience has shown that a higher value of 10000 milliseconds is more appropriate.

SystemType

Used to distinguish the flavor of knl we are dealing with. Possible options are "Dell" and "Intel". The default value is "Intel". This parameter is used only by the "knl_generic" plugin.

UmeCheckInterval

Interval, in microseconds, between checks for Uncorrectable Memory Errors (UME). If such errors are detected, the node will be set to a DOWN state and the slurmd daemon will shutdown. The default value is 0 (disabled). See also McPath.

ValidateMode

If set to 1 then validate, but do not modify the node's configured MCDRAM and NUMA modes from the slurm.conf file. If the actual modes do not match configured values the node will be set to a DOWN state. Every KNL nodes MCDRAM and NUMA states must both be listed in the slurm.conf file. This parameter is used only by the "knl_cray" plugin.

EXAMPLE

###################################################################
# knl_cray.conf
# Slurm configuration file for Intel Knights Landing on Cray system
###################################################################
CapmcPath=/opt/cray/capmc/default/bin/capmc
CapmcTimeout=6000
DefaultMCDRAM=flat
DefaultNUMA=a2a
NumaCpuBind=a2a=core;snc2=thread;snc4=thread
LogFile=/var/tmp/slurm_node_feature.log
SyscfgPath=/usr/sbin/syscfg

COPYING

This file is part of Slurm, a resource management program. For details, see <https://slurm.schedmd.com/>.

Slurm is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

Slurm is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.