--- /dev/null
+commit 5b3f143191d599c1fcca89125793405150c79424
+Author: Rodrigo Kumpera <kumpera@gmail.com>
+Date: Sun Apr 22 21:02:59 2012 -0300
+
+ Fix concurrent sweep thread start code to actually work.
+
+diff --git a/mono/metadata/sgen-marksweep.c b/mono/metadata/sgen-marksweep.c
+index 15e2767..78bc368 100644
+--- a/mono/metadata/sgen-marksweep.c
++++ b/mono/metadata/sgen-marksweep.c
+@@ -1960,7 +1960,7 @@ static void
+ post_param_init (void)
+ {
+ if (concurrent_sweep) {
+- if (mono_native_thread_create (&ms_sweep_thread, ms_sweep_thread_func, NULL)) {
++ if (!mono_native_thread_create (&ms_sweep_thread, ms_sweep_thread_func, NULL)) {
+ fprintf (stderr, "Error: Could not create sweep thread.\n");
+ exit (1);
+ }