19269: Update error text re modifying group role without can_manage.

[arvados.git] / services / crunch-dispatch-slurm / priority.go

diff --git a/services/crunch-dispatch-slurm/priority.go b/services/crunch-dispatch-slurm/priority.go
index 8c27043051bef1578987a8c25f6d7807d93013d3..515a98d323d36ddd55628c0ae3ef897a02d2900b 100644 (file)
--- a/services/crunch-dispatch-slurm/priority.go
+++ b/services/crunch-dispatch-slurm/priority.go
@@ -2,21 +2,29 @@
 //
 // SPDX-License-Identifier: AGPL-3.0
 
-package main
+package dispatchslurm
+
+const defaultSpread int64 = 10
 
 // wantNice calculates appropriate nice values for a set of SLURM
 // jobs. The returned slice will have len(jobs) elements.
 //
-// spread is a non-negative amount of space to leave between adjacent
+// spread is a positive amount of space to leave between adjacent
 // priorities when making adjustments. Generally, increasing spread
 // reduces the total number of adjustments made. A smaller spread
 // produces lower nice values, which is useful for old SLURM versions
 // with a limited "nice" range and for sites where SLURM is also
 // running non-Arvados jobs with low nice values.
+//
+// If spread<1, a sensible default (10) is used.
 func wantNice(jobs []*slurmJob, spread int64) []int64 {
        if len(jobs) == 0 {
                return nil
        }
+
+       if spread < 1 {
+               spread = defaultSpread
+       }
        renice := make([]int64, len(jobs))
 
        // highest usable priority (without going out of order)
@@ -27,13 +35,13 @@ func wantNice(jobs []*slurmJob, spread int64) []int64 {
                        // priority container gets the highest
                        // possible slurm priority.
                        target = job.priority + job.nice
-               } else if space := target - job.priority; space >= 0 && space < spread*10 {
+               } else if space := target - job.priority; space >= 0 && space < (spread-1)*10 {
                        // Ordering is correct, and interval isn't too
                        // large. Leave existing nice value alone.
                        renice[i] = job.nice
                        target = job.priority
                } else {
-                       target -= spread
+                       target -= (spread - 1)
                        if possible := job.priority + job.nice; target > possible {
                                // renice[i] is already 0, that's the
                                // best we can do