commit 838361c6cfb1319eadd59daaf9074dcdb92746e6

Author: Robert Schiele <rschiele@gmail.com>

Date:   Mon Sep 8 09:38:52 2014 +0200

    signal condition variable at end of stop_tracers

    stop_tracers modifies tp->is_done and thus must signal the condition

    variable tracer_wait_unblock is waiting on to monitor tp->is_done.

    Not doing so might cause the tool to deadlock if stop_tracers is

    called while a tracer thread is in tracer_wait_unblock.

    Signed-off-by: Robert Schiele <rschiele@gmail.com>

    Signed-off-by: Jens Axboe <axboe@fb.com>

diff --git a/blktrace.c b/blktrace.c

index 7e64c94..3c8fb4c 100644

--- a/blktrace.c

+++ b/blktrace.c

@@ -1913,6 +1913,7 @@ static void stop_tracers(void)

 		struct tracer *tp = list_entry(p, struct tracer, head);

 		tp->is_done = 1;

 	}

+	pthread_cond_broadcast(&mt_cond);

 }

 static void del_tracers(void)