From fb40bd78b0f91b274879cf5db8facd1e04b6052e Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Wed, 13 Feb 2008 15:03:37 -0800 Subject: Linux Kernel Markers: support multiple probes 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. Remove MARK_MAX_FORMAT_LEN, unused. This patch modifies the Linux Kernel Markers API : it removes the probe "arm/disarm" and changes the probe function prototype : it now expects a va_list * instead of a "...". If we want to have more than one probe connected to a marker at a given time (LTTng, or blktrace, ssytemtap) then we need this patch. Without it, connecting a second probe handler to a marker will fail. It allow us, for instance, to do interesting combinations : Do standard tracing with LTTng and, eventually, to compute statistics with SystemTAP, or to have a special trigger on an event that would call a systemtap script which would stop flight recorder tracing. Signed-off-by: Mathieu Desnoyers Cc: Christoph Hellwig Cc: Mike Mason Cc: Dipankar Sarma Cc: David Smith Cc: "Paul E. McKenney" Cc: "Frank Ch. Eigler" Cc: Steven Rostedt Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/module.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/module.h') diff --git a/include/linux/module.h b/include/linux/module.h index ac28e8761e84..330bec08c2c4 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -465,7 +465,7 @@ int unregister_module_notifier(struct notifier_block * nb); extern void print_modules(void); -extern void module_update_markers(struct module *probe_module, int *refcount); +extern void module_update_markers(void); #else /* !CONFIG_MODULES... */ #define EXPORT_SYMBOL(sym) -- cgit v1.2.3