From: David Goulet Date: Wed, 18 Dec 2013 23:34:44 +0000 (-0500) Subject: Fix: remove break in epoll loop of apps. thread X-Git-Url: http://git.efficios.com/?p=lttng-tools.git;a=commitdiff_plain;h=226e8f15071226f3d7911fd213000f8959c4bc76 Fix: remove break in epoll loop of apps. thread In *heavy* stress test with a large number of applications (> 7000 a second), the manage application thread could starve the delete process by breaking just after adding an application to the poll set. Also, we've observed that somehow the application unregister process is not done on most of the application by breaking the loop at each delete from the poll set. We are still uncertain why but one theory is that epoll detects that an I/O operation is ready (here a shutdown) and an other subsystem of the session daemon uses that socket for I/O which flags the poll event as "has been taken care of" thus the loop never sees it because of that break. The notify socket thread does not use a break between poll operation which leads us to that conclusion with the manage apps thread. We don't use epoll with edge-trigger thus a POLLERR/POLLHUP should always be return as long as it's not taken care of. Acked-by: Mathieu Desnoyers Signed-off-by: David Goulet --- diff --git a/src/bin/lttng-sessiond/main.c b/src/bin/lttng-sessiond/main.c index d4e62e32e..4d9b22de2 100644 --- a/src/bin/lttng-sessiond/main.c +++ b/src/bin/lttng-sessiond/main.c @@ -1410,10 +1410,6 @@ static void *thread_manage_apps(void *data) } DBG("Apps with sock %d added to poll set", sock); - - health_code_update(); - - break; } } else { /* @@ -1429,7 +1425,6 @@ static void *thread_manage_apps(void *data) /* Socket closed on remote end. */ ust_app_unregister(pollfd); - break; } }