doc: document vm timeout option perf impact

Mention that the `timeout` option has a noticeable performance impact. Fixes: nodejs#10453
addaleax · Apr 29, 2017 · bd59126 · bd59126
1 parent 765be6c
commit bd59126
Showing 1 changed file with 4 additions and 0 deletions.
diff --git a/doc/api/vm.md b/doc/api/vm.md
@@ -125,6 +125,10 @@ console.log(util.inspect(sandbox));
 // { animal: 'cat', count: 12, name: 'kitty' }
 ```
 
+*Note*: Using the `timeout` or `breakOnSigint` options will result in new
+event loops and corresponding threads being started, which have a non-zero
+performance overhead.
+
 ### script.runInNewContext([sandbox][, options])
 <!-- YAML
 added: v0.3.1