RCU style multiple probes support for the Linux Kernel Markers.
Common case (one probe) is still fast and does not require dynamic allocation
or a supplementary pointer dereference on the fast path.
- Move preempt disable from the marker site to the callback.
Since we now have an internal callback, move the preempt disable/enable to the
callback instead of the marker site.
Since the callback change is done asynchronously (passing from a handler that
supports arguments to a handler that does not setup the arguments is no
arguments are passed), we can safely update it even if it is outside the preempt
disable section.
- Move probe arm to probe connection. Now, a connected probe is automatically
armed.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
---
include/linux/marker.h | 51 +--
include/linux/module.h | 2
kernel/marker.c | 663 +++++++++++++++++++++++++++++-----------
kernel/module.c | 7
samples/markers/probe-example.c | 33 +
5 files changed, 546 insertions(+), 210 deletions(-)
Index: linux-2.6-lttng/include/linux/marker.h
===================================================================
--- linux-2.6-lttng.orig/include/linux/marker.h 2007-11-13 09:48:35.000000000 -0500
+++ linux-2.6-lttng/include/linux/marker.h 2007-11-13 09:48:41.000000000 -0500
@@ -19,16 +19,23 @@ struct marker;
/**
* marker_probe_func - Type of a marker probe function
- * @mdata: pointer of type struct marker
- * @private_data: caller site private data
+ * @probe_data: probe private data
+ * @private_data: call site private data
* @fmt: format string
- * @...: variable argument list
+ * @args: variable argument list pointer. Use a pointer to overcome C's
+ * inability to pass this around as a pointer in a portable manner in
+ * the callee otherwise.
*
* Type of marker probe functions. They receive the mdata and need to parse the
* format string to recover the variable ...
