Merge pull request #3958 from simplesurance/swappiness

fix: disable swap for executor_linux allocations

CHANGELOG.md

@@ -43,6 +43,7 @@ BUG FIXES:
    space in it on Windows [[GH-3855](https://github.com/hashicorp/nomad/issues/3855)]
  * client/vault: Recognize renewing non-renewable Vault lease as fatal [[GH-3727](https://github.com/hashicorp/nomad/issues/3727)]
  * config: Revert minimum CPU limit back to 20 from 100.
+ * driver/exec: Properly disable swapping [[GH-3958](https://github.com/hashicorp/nomad/issues/3958)]
  * driver/lxc: Cleanup LXC containers after errors on container startup. [[GH-3773](https://github.com/hashicorp/nomad/issues/3773)]
  * ui: Fix ui on non-leaders when ACLs are enabled [[GH-3722](https://github.com/hashicorp/nomad/issues/3722)]
  * ui: Fix requests using client-side certificates in Firefox. [[GH-3728](https://github.com/hashicorp/nomad/pull/3728)]

client/driver/executor/executor_linux.go

@@ -83,7 +83,8 @@ func (e *UniversalExecutor) configureCgroups(resources *structs.Resources) error
 		// Total amount of memory allowed to consume
 		e.resConCtx.groups.Resources.Memory = int64(resources.MemoryMB * 1024 * 1024)
 		// Disable swap to avoid issues on the machine
-		e.resConCtx.groups.Resources.MemorySwap = int64(-1)
+		var memSwappiness int64 = 0
+		e.resConCtx.groups.Resources.MemorySwappiness = &memSwappiness
 	}
 
 	if resources.CPU < 2 {