PR31597: Allow time for data in buffers to be read out before shutdown

On SystemTap scripts using the -c <command> option some data was
dropped from the output.  This was observed with sporadic failures of
the *syscall.exp tests.  The process of shutting down the transport
layer moving data from the kernel- to user-space was not allowing time
for data to be completely drained from the buffers. A delay has been
added in the shutdown process to provided the needed time to drain the
buffers.

diff --git a/staprun/relay.c b/staprun/relay.c
index cfd26331628547dcea0db0acd29ff3ba59e8dd15..f88fdfc3dcbf3f64d6ddc879ba9983cff4f960bf 100644 (file)
--- a/staprun/relay.c
+++ b/staprun/relay.c
@@ -816,6 +816,7 @@ int init_relayfs(void)
 void close_relayfs(void)
 {
        int i;
+       usleep(reader_timeout_ms*2*1000); /* PR31597, delay to drain buffers */
        stop_threads = 1;
        dbug(2, "closing\n");