[patch 04/16] Markers use rcu_*_sched_notrace and notrace

Mathieu Desnoyers
2008-11-14T23:04:59Z

[-- Attachment #1: markers-use-rcu-sched-notrace.patch --]
[-- Type: text/plain, Size: 3068 bytes --]

Make marker critical code use notrace (__attribute__((no_instrument_function))
to make sure they can be used as an ftrace callback.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Masami Hiramatsu <mhiramat@redhat.com>
CC: 'Peter Zijlstra' <peterz@infradead.org>
CC: "Frank Ch. Eigler" <fche@redhat.com>
CC: 'Ingo Molnar' <mingo@elte.hu>
CC: Lai Jiangshan <laijs@cn.fujitsu.com>
CC: 'Hideo AOKI' <haoki@redhat.com>
CC: Takashi Nishiie <t-nishiie@np.css.fujitsu.com>
CC: 'Steven Rostedt' <rostedt@goodmis.org>
---
kernel/marker.c | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)

Index: linux-2.6-lttng/kernel/marker.c
===================================================================
--- linux-2.6-lttng.orig/kernel/marker.c 2008-10-15 09:43:15.000000000 -0400
+++ linux-2.6-lttng/kernel/marker.c 2008-10-15 09:44:08.000000000 -0400
@@ -81,7 +81,7 @@ struct marker_entry {
* though the function pointer change and the marker enabling are two distinct
* operations that modifies the execution flow of preemptible code.
*/
-void __mark_empty_function(void *probe_private, void *call_private,
+notrace void __mark_empty_function(void *probe_private, void *call_private,
const char *fmt, va_list *args)
{
}
@@ -97,7 +97,8 @@ EXPORT_SYMBOL_GPL(__mark_empty_function)
* need to put a full smp_rmb() in this branch. This is why we do not use
* rcu_dereference() for the pointer read.
*/
-void marker_probe_cb(const struct marker *mdata, void *call_private, ...)
+notrace void marker_probe_cb(const struct marker *mdata,
+ void *call_private, ...)
{
va_list args;
char ptype;
@@ -107,7 +108,7 @@ void marker_probe_cb(const struct marker
* sure the teardown of the callbacks can be done correctly when they
* are in modules and they insure RCU read coherency.
*/
- rcu_read_lock_sched();
+ rcu_read_lock_sched_notrace();
ptype = mdata->ptype;
if (likely(!ptype)) {
marker_probe_func *func;
@@ -145,7 +146,7 @@ void marker_probe_cb(const struct marker
va_end(args);
}
}
- rcu_read_unlock_sched();
+ rcu_read_unlock_sched_notrace();
}
EXPORT_SYMBOL_GPL(marker_probe_cb);

@@ -157,12 +158,13 @@ EXPORT_SYMBOL_GPL(marker_probe_cb);
*
* Should be connected to markers "MARK_NOARGS".
*/
-static void marker_probe_cb_noarg(const struct marker *mdata, void *call_private, ...)
+static notrace void marker_probe_cb_noarg(const struct marker *mdata,
+ void *call_private, ...)
{
va_list args; /* not initialized */
char ptype;

- rcu_read_lock_sched();
+ rcu_read_lock_sched_notrace();
ptype = mdata->ptype;
if (likely(!ptype)) {
marker_probe_func *func;
@@ -195,7 +197,7 @@ static void marker_probe_cb_noarg(const
multi[i].func(multi[i].probe_private, call_private,
mdata->format, &args);
}
- rcu_read_unlock_sched();
+ rcu_read_unlock_sched_notrace();
}

static void free_old_closure(struct rcu_head *head)