Add log when out-of-memory during vm start

diff --git a/xenvm/vmact.ml b/xenvm/vmact.ml
index 83bf12b74d70456f680e90fe325904d14d6cae83..04f8039a0fd1f3a5b67baef20faa2b33c00b02b5 100644 (file)
--- a/xenvm/vmact.ml
+++ b/xenvm/vmact.ml
@@ -599,12 +599,14 @@ let build_vm xc xs state f restore =
 
 let start_vm xc xs state =
        maybe (fun cfg -> state.vm_next_cfg <- None; state.vm_cfg <- cfg) state.vm_next_cfg;
-
        let cfg = state.vm_cfg in
        if not cfg.no_mem_check then (
                let requested_kib = Memory.required_to_boot cfg.hvm cfg.vcpus cfg.memory cfg.memory 1. in
-               if not (Memory.wait_xen_free_mem ~xc requested_kib) then
-                       raise (Not_enough_free_memory cfg);
+               if not (Memory.wait_xen_free_mem ~xc requested_kib) then (
+                       let avail_kib = Memory.get_free_memory_kib ~xc in
+                       warn "failed to reserve enough memory, requested %Ld, available %Ld" requested_kib avail_kib;
+                       raise (Not_enough_free_memory cfg)
+               )
        );
 
        let from_scratch =