Add support for SALLOC_CONSTRAINT, SBATCH_CONSTRAINT and SLURM_CONSTRAINT
    environment variables to set default constraints for salloc, sbatch and
    srun commands respectively.
Bug 3317

node_features/knl_cray - Fix possible race condition when changing node
    state that could result in old KNL mode as an active features.
bug 3235

cray/burst_buffer - Increase time to synchronize operations between threads
    from 5 to 60 seconds ("setup" operation time observed over 17 seconds).
    This should fix a race condition between a thread performing a buffer
    creation (setup) and a thread looking for unexpected buffers. If a
    buffer is found during the time window allowed for creation, it's
    space will be counted twice. First by the status checking thread
    and second by the thread doing the creation. The deallocation only
    happens once, so the used space information can be left with an
    invalid value.
bug 3295

static variable means multiple active decompression streams will corrupt
zlib's internal state, which can lead to a segfault.

Bug 3299.

On a reconfig, the exc_node_bitmap is cleared but then it was
not built again since last_work_scan was declared as a local static
variable in _do_power_work(). The fix is to make it global within the
plugin and reinitialize it to 0 on _init_power_config().

Bug 3078.

For example:
     Nodes=nid00001 CPU_IDs=2-3 Mem=1000 GRES_IDX=gpu:alpha(IDX:2)
     Nodes=nid00002 CPU_IDs=0-1 Mem=1000 GRES_IDX=gpu:alpha(IDX:0)

Bug 3291.

If GRES are configured with file IDs, then "scontrol -d show node" will
    not only identify the count of currently allocated GRES, but their specific
    index numbers (e.g. "GresUsed=gpu:alpha:2(IDX:0,2),gpu:beta:0(IDX:N/A)").

Bug 3267.

Termination can race against step creation if, e.g., ill-behaved SPANK plugins
are in use.

Bug 3248.

Added SchedulingParameters option of "bf_job_part_count_reserve". Jobs below
    the specified threshold will not have resources reserved for them.
bug 3275

messages.  Hopefully this will reduce the number of messages lost when
filling up memory when the database/DBD is down.

sched/backfill plugin: Make malloc match data type (defined as uint32_t and
    allocated as int). No failures observed, if type "int" is smaller than
    "uint32_t", it could result in an invalid memory reference.

Fix API call: slurm_job_cpus_allocated_str_on_node_id() and
in turn slurm_job_cpus_allocated_str_on_node() to return correct
results for anything but first node. This was caused by missed logic
to calculate fist bit belongs to particular node. Lookup was always
starting from bit 0.

Bug 3266.

After one second of wall time, simulate the termination of all remaining
   running jobs in order to respond in a reasonable time frame.
bug 3275

Modify backfill algorithm to improve performance with large numbers of
    running jobs. Group running jobs that end in a "similar" time frame using a
    time window that grows exponentially rather than linearly. The original
    window sizes were (in units of minutes):
    0, 1, 2, 3, 4, 5, 6, 7, ... minutes
    The new window sizes are:
    0.5, 1, 2, 4, 8, 16, 32, ... minutes
    This can dramatically reduce the number of instances where the very time
    consuming "can the pending job run now" operation is executed, especailly
    if there are 1000+ running jobs.
bug 3275

Modify several NEWS items for greater clarity.

Add new PriorityFlags option of INCR_ONLY, which prevents a job's priority
    from being decremented.
Added for NERSC

If a node is booting for some job, don't allocate additional jobs to the
    node until the boot completes.
but 3256

Found with valgrind. Bug 2846.

Move where we set the configuration table bitmaps in order to support
  the backup slurmctld starting and recovering previously saved
  KNL mode information (which can necessitate rebuilding the node
  configuration table).
bug 3241

Bug 3255.

Since CLE 5.1 I believe, /var/spool/alps is a symlink to
/var/opt/cray/alps/spool, so it should be safe to use
/var/opt/cray/alps/spool.

Bug 3253.

Bug 3253.

If the input value mod 512 == 0, the value would be subject to
unintended rounding. Rework the function to check against this
on each unit promotion.

Bug 3252.

It was causing the loss of node available_features on startup with
  node_features/knl_cray
bug 3241

Check for zonesort file first, to save time over attempting to load
  a module that is already loaded. It may be loaded by default per
  administrator configuration.

Set per-node HBM availability as a GRES based upon the KNL node's
  MCDRAM state
bug 3171

Caused by race for local_energy which is dynamically allocated. Bail out
of the update if that hasn't been allocated yet.

Bug 3237.

Add new node state flag of NODE_STATE_REBOOT for node reboots triggered by
    "scontrol reboot" commands. Previous logic re-used NODE_STATE_MAINT flag,
    which could lead to inconsistencies. Add "ASAP" option to "scontrol reboot"
    command that will drain a node in order to reboot it as soon as possible,
    then return it to service.
bug 3210

bug 3213

select/linear plugin modified to better support heterogeneous clusters when
    topology/none is also configured. Note that use of the select/cons_res
    plugin is strongly recommended for heterogeneous clusters. The use of
    OverSubscribe=exclusive can be used if whole node allocations is
    desired.
bug 3212

Bug 3224.

If a job is started by the main scheduling logic and requeued while
  the backfill scheduler has locks released, that can result in an
  invalid data structure in select/cons_res. Namely, the backfill
  scheduler's attempt to start the job would clear the job resources
  node_bitmap. That leaves a NULL pointer in the select/cons_res
  plugin generating an abort. (That pointer is needed to clean up
  the job allocation records when the Epilog or Cray Node Health
  Check, NHC, are complete and the resources become available for
  another job.
bug 3230

Backup slurmctld will now
1. Not abort due to NULL pointer (needed to move code around on restart)
2. Recover KNL MCDRAM and NUMA modes from state save files if capmc and
   cnselect not available
bug 3241