diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 56485115d65..f8ca4e88e07 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,16 @@
+2015-02-06  Pedro Alves  <palves@redhat.com>
+
+	* gdb.threads/attach-many-short-lived-threads.c (SECONDS): New
+	macro.
+	(seconds_left, again): New globals.
+	(main): Wait seconds_left in a 1-second sleep loop instead of
+	sleeping 180 seconds.  If 'again' is set, reset the seconds
+	counter.
+	* gdb.threads/attach-many-short-lived-threads.exp (test): Set
+	'again' in the inferior before detaching.  Print the seconds left.
+	(options): New global.
+	(top level): Build program with	-DTIMEOUT=$timeout.
+
 2015-02-06  Pedro Alves  <palves@redhat.com>
 
 	* gdb.base/gdb-sigterm.c (main): Use the TIMEOUT define to
diff --git a/gdb/testsuite/gdb.threads/attach-many-short-lived-threads.c b/gdb/testsuite/gdb.threads/attach-many-short-lived-threads.c
index 001f2ffe80a..4a750228394 100644
--- a/gdb/testsuite/gdb.threads/attach-many-short-lived-threads.c
+++ b/gdb/testsuite/gdb.threads/attach-many-short-lived-threads.c
@@ -113,6 +113,17 @@ detached_fn (void *arg)
   return NULL;
 }
 
+/* Allow for as much timeout as DejaGnu wants, plus a bit of
+   slack.  */
+#define SECONDS (TIMEOUT + 20)
+
+/* We'll exit after this many seconds.  */
+unsigned int seconds_left = SECONDS;
+
+/* GDB sets this whenever it's about to start a new detach/attach
+   sequence.  We react by resetting the seconds left counter.  */
+volatile int again = 0;
+
 int
 main (int argc, char *argv[])
 {
@@ -144,8 +155,20 @@ main (int argc, char *argv[])
       create_thread (&detached_attr, detached_fn, NULL);
     }
 
-  /* Long enough for all the attach/detach sequences done by the .exp
-     file.  */
-  sleep (180);
+  /* Exit after a while if GDB is gone/crashes.  But wait long enough
+     for one attach/detach sequence done by the .exp file.  */
+  while (--seconds_left > 0)
+    {
+      sleep (1);
+
+      if (again)
+	{
+	  /* GDB should be reattaching soon.  Restart the timer.  */
+	  again = 0;
+	  seconds_left = SECONDS;
+	}
+    }
+
+  printf ("timeout, exiting\n");
   return 0;
 }
diff --git a/gdb/testsuite/gdb.threads/attach-many-short-lived-threads.exp b/gdb/testsuite/gdb.threads/attach-many-short-lived-threads.exp
index 96c98ea843d..2c2236da2e9 100644
--- a/gdb/testsuite/gdb.threads/attach-many-short-lived-threads.exp
+++ b/gdb/testsuite/gdb.threads/attach-many-short-lived-threads.exp
@@ -112,6 +112,12 @@ proc test {} {
 	    }
 
 	    if {$attempt < $attempts} {
+		# Kick the time out timer for another round.
+		gdb_test "print again = 1" " = 1" "reset timer in the inferior"
+		# Show the time we had left in the logs, in case
+		# something goes wrong.
+		gdb_test "print seconds_left" " = .*"
+
 		gdb_test "detach" "Detaching from.*"
 	    } else {
 		gdb_test "kill" "" "kill process" "Kill the program being debugged.*y or n. $" "y"
@@ -125,7 +131,12 @@ proc test {} {
     remote_exec target "kill -9 ${testpid}"
 }
 
-if {[prepare_for_testing "failed to prepare" $testfile $srcfile {debug pthreads}] == -1} {
+# The test program exits after a while, in case GDB crashes.  Make it
+# wait at least as long as we may wait before declaring a time out
+# failure.
+set options { "additional_flags=-DTIMEOUT=$timeout" debug pthreads }
+
+if {[prepare_for_testing "failed to prepare" $testfile $srcfile $options] == -1} {
     return -1
 }