ts-xen-build-prep: Run the backgrounded resize2fs with ionice

We wrap this in
  ionice -cBest-Effort -n7

This is an attempt to stop resize2fs from starving builds of IO
bandwidth.  We have been seeing that some IO-intensive build steps
(notably, configure) can take unreasonable amounts of time and we
suspect resize2fs as the culprit.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>

diff --git a/ts-xen-build-prep b/ts-xen-build-prep
index 0e68cd30c2013a82aadaefae79922b1f11511a13..05a7857d55c25e98addd6bf6931eb584a0407dce 100755 (executable)
--- a/ts-xen-build-prep
+++ b/ts-xen-build-prep
@@ -159,7 +159,10 @@ sub lvextend1 ($$$) {
     if (!$background) {
        target_cmd_root($ho, $cmd, $timeout);
     } else {
-       target_cmd_root($ho, "$cmd >>resizefs.log 2>&1 </dev/null &", 30);
+       target_cmd_root($ho,
+                       "ionice -cBest-Effort -n7 ".
+                       "$cmd >>resizefs.log 2>&1 </dev/null &",
+                       30);
     }
 }