If a job requests a specific memory requirement then gets something else

from the slurmctld make sure the step allocation is made aware of it.

Bug 3926

Also see commit b30139e5

NEWS

@@ -35,6 +35,8 @@ documents those changes that are of interest to users and administrators.
  -- Performance boost for when Slurm is dealing with credentials.
  -- Fix race condition which could leave a stepd hung on shutdown.
  -- Add lua support for opensuse.
+ -- If a job requests a specific memory requirement then gets something else
+    from the slurmctld make sure the step allocation is made aware of it.
 
 * Changes in Slurm 17.02.4
 ==========================

src/srun/libsrun/allocate.c

@@ -500,13 +500,15 @@ allocate_nodes(bool handle_signals)
 		 * allocated so we don't have issues when we use them
 		 * in the step creation.
 		 */
-//XXXX pn_min_memory here is an int, not uint. these bit operations may have some bizarre side effects
-		if (opt.pn_min_memory != NO_VAL64)
-			opt.pn_min_memory = (resp->pn_min_memory &
-					     (~MEM_PER_CPU));
-		else if (opt.mem_per_cpu != NO_VAL64)
-			opt.mem_per_cpu = (resp->pn_min_memory &
-					   (~MEM_PER_CPU));
+		opt.pn_min_memory = NO_VAL64;
+		opt.mem_per_cpu = NO_VAL64;
+		if (resp->pn_min_memory != NO_VAL64) {
+			if (resp->pn_min_memory & MEM_PER_CPU)
+				opt.mem_per_cpu = (resp->pn_min_memory &
+						   (~MEM_PER_CPU));
+			else
+				opt.pn_min_memory = resp->pn_min_memory;
+		}
 		/*
 		 * FIXME: timelimit should probably also be updated
 		 * here since it could also change.