relayd: rename fd-cap parameter to fd-pool-size

[lttng-tools.git] / src / common / defaults.h

diff --git a/src/common/defaults.h b/src/common/defaults.h
index e57e6495fa7509056e308238caed41d6dfd60b54..56a7c94490014ae5cda156659dcb8c24a8609c2e 100644 (file)
--- a/src/common/defaults.h
+++ b/src/common/defaults.h
@@ -93,7 +93,20 @@
 #define DEFAULT_RELAYD_RUNDIR                  "%s"
 #define DEFAULT_RELAYD_PATH                    DEFAULT_RELAYD_RUNDIR "/relayd"
 
-#define DEFAULT_RELAYD_MINIMAL_FD_CAP          30
+#define DEFAULT_RELAYD_MIN_FD_POOL_SIZE                100
+/*
+ * The file descriptor pool size needs a reserve buffer to accomodate the
+ * indirect use of short-lived file descriptors. For instance, glibc will
+ * create a socket (and thus, use an fd) during calls to gethostname() or
+ * when querying the user's group. Other calls also probably make use of
+ * short-lived FDs.
+ *
+ * The theoritical maximal reserve corresponds to the number of threads as,
+ * in the worst case, they could all be making such calls.
+ *
+ * This value must be less than DEFAULT_RELAYD_MIN_FD_POOL_SIZE.
+ */
+#define DEFAULT_RELAYD_FD_POOL_SIZE_RESERVE    10
 
 /* Default lttng run directory */
 #define DEFAULT_LTTNG_HOME_ENV_VAR              "LTTNG_HOME"