Provided by: slurm-client_18.08.6.2-1build1_amd64 bug

NAME

       cgroup.conf - Slurm configuration file for the cgroup support

DESCRIPTION

       cgroup.conf is an ASCII file which defines parameters used by Slurm's Linux cgroup related
       plugins.   The  file  location  can  be  modified  at  system   build   time   using   the
       DEFAULT_SLURM_CONF  parameter  or  at execution time by setting the SLURM_CONF environment
       variable. The file will always be located in the same directory as the slurm.conf file.

       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.

       For    general    Slurm    Cgroups    information,    see    the    Cgroups    Guide    at
       <https://slurm.schedmd.com/cgroups.html>.

       The following cgroup.conf parameters are defined to control the general behavior of  Slurm
       cgroup plugins.

       CgroupAutomount=<yes|no>
              Slurm  cgroup  plugins  require valid and functional cgroup subsystem to be mounted
              under  /sys/fs/cgroup/<subsystem_name>.   When  launched,   plugins   check   their
              subsystem   availability.   If  not  available,  the  plugin  launch  fails  unless
              CgroupAutomount is set to yes. In that case, the plugin will first try to mount the
              required subsystems.

       CgroupMountpoint=PATH
              Specify  the  PATH under which cgroups should be mounted. This should be a writable
              directory which will contain cgroups mounted one per subsystem. The default PATH is
              /sys/fs/cgroup.

TASK/CGROUP PLUGIN

       The  following  cgroup.conf  parameters  are  defined  to  control  the  behavior  of this
       particular plugin:

       AllowedKmemSpace=<number>
              Constrain the job cgroup kernel memory to this  amount  of  the  allocated  memory,
              specified in bytes. The AllowedKmemSpace must be between the upper and lower memory
              limits,  specified   by   MaxKmemPercent   and   MinKmemSpace,   respectivley.   If
              AllowedKmemSpace  goes  beyond  the  upper or lower limit, it will be reset to that
              upper or lower limit, whichever has been exceeded.

       AllowedRAMSpace=<number>
              Constrain the job cgroup RAM to this  percentage  of  the  allocated  memory.   The
              percentage  supplied  may  be expressed as floating point number, e.g. 98.5. If the
              AllowedRAMSpace limit is exceeded, the job steps  will  be  killed  and  a  warning
              message  will  be  written  to  standard  error.   Also see ConstrainRAMSpace.  The
              default value is 100.

       AllowedSwapSpace=<number>
              Constrain the job cgroup swap space to this percentage  of  the  allocated  memory.
              The   default   value   is  0,  which  means  that  RAM+Swap  will  be  limited  to
              AllowedRAMSpace. The supplied percentage may  be  expressed  as  a  floating  point
              number,  e.g.  50.5.   If the limit is exceeded, the job steps will be killed and a
              warning message will be written to standard error.   Also  see  ConstrainSwapSpace.
              NOTE:  Setting  AllowedSwapSpace to 0 does not restrict the Linux kernel from using
              swap space. To control how the kernel uses swap space, see MemorySwappiness.

       ConstrainCores=<yes|no>
              If configured to "yes" then constrain allowed cores  to  the  subset  of  allocated
              resources.  This  functionality  makes  use  of the cpuset subsystem.  Due to a bug
              fixed in version 1.11.5 of HWLOC, the  task/affinity  plugin  may  be  required  in
              addition to task/cgroup for this to function properly.  The default value is "no".

       ConstrainDevices=<yes|no>
              If  configured  to  "yes"  then  constrain  the job's allowed devices based on GRES
              allocated resources. It uses the devices subsystem for that.  The default value  is
              "no".

       ConstrainKmemSpace=<yes|no>
              If  configured  to "yes" then constrain the job's Kmem RAM usage in addition to RAM
              usage. Only takes effect if ConstrainRAMSpace is set to "yes". The default value is
              "no".  If  set to yes, the job's Kmem limit will be set to AllowedKmemSpace if set;
              otherwise, the  job's  Kmem  limit  will  be  set  to  its  RAM  limit.   Also  see
              AllowedKmemSpace.

       ConstrainRAMSpace=<yes|no>
              If  configured  to  "yes"  then constrain the job's RAM usage by setting the memory
              soft limit to the allocated memory and the hard limit to  the  allocated  memory  *
              AllowedRAMSpace.  The default value is "no", in which case the job's RAM limit will
              be set to its swap space limit if ConstrainSwapSpace is set  to  "yes".   Also  see
              AllowedSwapSpace,  AllowedRAMSpace  and  ConstrainSwapSpace.   NOTE:  When enabled,
              ConstrainRAMSpace can lead to a noticiable  decline  in  per-node  job  throughout.
              Sites with high-throughput requirements should carefully weigh the tradeoff between
              per-node throughput, versus potential problems that can  arise  from  unconstrained
              memory  usage on the node. See <https://slurm.schedmd.com/high_throughput.html> for
              further discussion.

       ConstrainSwapSpace=<yes|no>
              If configured to "yes" then constrain the job's  swap  space  usage.   The  default
              value  is  "no".  Note that when set to "yes" and ConstrainRAMSpace is set to "no",
              AllowedRAMSpace is automatically set to 100% in order to limit the RAM+Swap  amount
              to 100% of job's requirement plus the percent of allowed swap space. This amount is
              thus set to both RAM and RAM+Swap limits. This means that in that particular  case,
              ConstrainRAMSpace is automatically enabled with the same limit than the one used to
              constrain swap space.  Also see AllowedSwapSpace.

       MaxRAMPercent=PERCENT
              Set an upper bound in percent of total RAM on the RAM constraint for a  job.   This
              will  be  the  memory  constraint applied to jobs that are not explicitly allocated
              memory by Slurm (i.e. Slurm's select plugin is  not  configured  to  manage  memory
              allocations).  The  PERCENT  may be an arbitrary floating point number. The default
              value is 100.

       MaxSwapPercent=PERCENT
              Set an upper bound (in percent of total RAM) on the amount of RAM+Swap that may  be
              used for a job. This will be the swap limit applied to jobs on systems where memory
              is not being explicitly allocated to job. The PERCENT may be an arbitrary  floating
              point number between 0 and 100.  The default value is 100.

       MaxKmemPercent=PERCENT
              Set  an  upper  bound  in  percent  of  total Kmem for a job. The PERCENT may be an
              arbitrary floating point number. The default value is 100.

       MemorySwappiness=<number>
              Configure the kernel's priority for swapping out anonymous pages (such  as  program
              data)  verses  file  cache pages for the job cgroup. Valid values are between 0 and
              100, inclusive. A value of 0 prevents the kernel from swapping out program data.  A
              value  of  100 gives equal priorioty to swapping out file cache or anonymous pages.
              If not set, then the  kernel's  default  swappiness  value  will  be  used.  Either
              ConstrainRAMSpace  or  ConstrainSwapSpace  must  be  set  to  yes in order for this
              parameter to be applied.

       MinKmemSpace=<number>
              Set a lower bound (in MB) on the memory limits  defined  by  AllowedKmemSpace.  The
              default limit is 30M.

       MinRAMSpace=<number>
              Set  a  lower  bound  (in  MB)  on the memory limits defined by AllowedRAMSpace and
              AllowedSwapSpace. This prevents accidentally creating a memory cgroup with  such  a
              low  limit  that  slurmstepd  is immediately killed due to lack of RAM. The default
              limit is 30M.

       TaskAffinity=<yes|no>
              If configured to "yes" then set a default task affinity to bind each step task to a
              subset  of the allocated cores using sched_setaffinity.  The default value is "no".
              Note: This feature requires the Portable Hardware Locality (hwloc)  library  to  be
              installed.

DISTRIBUTION-SPECIFIC NOTES

       Debian  and  derivatives (e.g. Ubuntu) usually exclude the memory and memsw (swap) cgroups
       by default. To include them, add the following parameters  to  the  kernel  command  line:
       cgroup_enable=memory swapaccount=1

       This  can usually be placed in /etc/default/grub inside the GRUB_CMDLINE_LINUX variable. A
       command such as update-grub must be run after updating the file.

EXAMPLE

       ###
       # Slurm cgroup support configuration file
       ###
       CgroupAutomount=yes
       ConstrainCores=yes
       #

COPYING

       Copyright (C) 2010-2012  Lawrence  Livermore  National  Security.   Produced  at  Lawrence
       Livermore National Laboratory (cf, DISCLAIMER).
       Copyright (C) 2010-2016 SchedMD LLC.

       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.

SEE ALSO

       slurm.conf(5)