diff -r 3a57eafd8401 Python/condvar.h
--- a/Python/condvar.h	Tue May 24 09:15:14 2016 +0300
+++ b/Python/condvar.h	Fri Jun 03 11:36:50 2016 +0200
@@ -87,6 +87,8 @@
 #define PyCOND_BROADCAST(cond)  pthread_cond_broadcast(cond)
 #define PyCOND_WAIT(cond, mut)  pthread_cond_wait((cond), (mut))
 
+#define MINIMUM_TIMEOUT 100
+
 /* return 0 for success, 1 on timeout, -1 on error */
 Py_LOCAL_INLINE(int)
 PyCOND_TIMEDWAIT(PyCOND_T *cond, PyMUTEX_T *mut, PY_LONG_LONG us)
@@ -95,10 +97,31 @@
     struct timespec ts;
     struct timeval deadline;
 
-    PyCOND_GETTIMEOFDAY(&deadline);
-    PyCOND_ADD_MICROSECONDS(deadline, us);
-    ts.tv_sec = deadline.tv_sec;
-    ts.tv_nsec = deadline.tv_usec * 1000;
+    while(1) {
+        long delta;
+        struct timeval ct;
+
+        PyCOND_GETTIMEOFDAY(&deadline);
+        PyCOND_ADD_MICROSECONDS(deadline, us);
+        ts.tv_sec = deadline.tv_sec;
+        ts.tv_nsec = deadline.tv_usec * 1000;
+
+        /* Retry with a greater timeout when deadline is already in the past
+         * for a very slow hardware. When the timeout is greater than
+         * MINIMUM_TIMEOUT, it is considered that this cannot happen, whatever
+         * the hardware being used. */
+        if (us < MINIMUM_TIMEOUT) {
+            PyCOND_GETTIMEOFDAY(&ct);
+            if ((delta=(ct.tv_sec - deadline.tv_sec) * 1000000 +
+                    (ct.tv_usec - deadline.tv_usec)) > 0) {
+                us += delta;
+                printf("%ld\n", delta);
+                continue;
+            }
+        }
+        printf("Ok\n");
+        break;
+    }
 
     r = pthread_cond_timedwait((cond), (mut), &ts);
     if (r == ETIMEDOUT)