ts-hosts-allocate-Executive: Treat "no suitable host" as starved

In particular, this means that
 * platform-* jobs will not cause problems in old Xen branches when
   there a platform supports only newer Xen
 * commissioning flights will complain less about the architectures
   that aren't included in the particular set of hosts

The motivation for this patch, now, is that the first of these applies
to `platform-thunderx', recently introduced in the Xen Project colo.

CC: Julien Grall <julien.grall@arm.com>
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>

diff --git a/ts-hosts-allocate-Executive b/ts-hosts-allocate-Executive
index af1876315003f624c76b35b12ea310f0884e36d9..3bc38102f3f784c42a7578df22da2526edd601c7 100755 (executable)
--- a/ts-hosts-allocate-Executive
+++ b/ts-hosts-allocate-Executive
@@ -845,8 +845,8 @@ sub attempt_allocation {
     hid_recurse({}, 0);
 
     if (!$best) {
-       logm("no plan is possible");
-       die "no plan is possible";
+       logm("no plan is possible - no suitable hosts");
+       return $alloc_starved_r;
     }
 
     foreach (my $ix=0; $ix<@hids; $ix++) {