Fix stack inline

Decrease stack usage for various call paths by forcing certain
functions to be inlined.  By inlining the functions the overhead
of a new stack frame is removed at the cost of increased code size.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>

module/zfs/zio.c

@@ -436,7 +436,8 @@ zio_wait_for_children(zio_t *zio, enum zio_child child, enum zio_wait_type wait)
 	return (waiting);
 }
 
-static void
+__attribute__((always_inline))
+static inline void
 zio_notify_parent(zio_t *pio, zio_t *zio, enum zio_wait_type wait)
 {
 	uint64_t *countp = &pio->io_children[zio->io_child_type][wait];