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-rw-r--r--include/linux/trace_events.h1
-rw-r--r--kernel/trace/trace_output.c66
2 files changed, 16 insertions, 51 deletions
diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h
index 20749bd9db71..bb2053246d6a 100644
--- a/include/linux/trace_events.h
+++ b/include/linux/trace_events.h
@@ -136,7 +136,6 @@ struct trace_event_functions {
struct trace_event {
struct hlist_node node;
- struct list_head list;
int type;
struct trace_event_functions *funcs;
};
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 67f47ea27921..f0ba97121345 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -11,6 +11,7 @@
#include <linux/kprobes.h>
#include <linux/sched/clock.h>
#include <linux/sched/mm.h>
+#include <linux/idr.h>
#include "trace_output.h"
@@ -21,8 +22,6 @@ DECLARE_RWSEM(trace_event_sem);
static struct hlist_head event_hash[EVENT_HASHSIZE] __read_mostly;
-static int next_event_type = __TRACE_LAST_TYPE;
-
enum print_line_t trace_print_bputs_msg_only(struct trace_iterator *iter)
{
struct trace_seq *s = &iter->seq;
@@ -688,38 +687,23 @@ struct trace_event *ftrace_find_event(int type)
return NULL;
}
-static LIST_HEAD(ftrace_event_list);
+static DEFINE_IDA(trace_event_ida);
-static int trace_search_list(struct list_head **list)
+static void free_trace_event_type(int type)
{
- struct trace_event *e = NULL, *iter;
- int next = __TRACE_LAST_TYPE;
-
- if (list_empty(&ftrace_event_list)) {
- *list = &ftrace_event_list;
- return next;
- }
+ if (type >= __TRACE_LAST_TYPE)
+ ida_free(&trace_event_ida, type);
+}
- /*
- * We used up all possible max events,
- * lets see if somebody freed one.
- */
- list_for_each_entry(iter, &ftrace_event_list, list) {
- if (iter->type != next) {
- e = iter;
- break;
- }
- next++;
- }
+static int alloc_trace_event_type(void)
+{
+ int next;
- /* Did we used up all 65 thousand events??? */
- if (next > TRACE_EVENT_TYPE_MAX)
+ /* Skip static defined type numbers */
+ next = ida_alloc_range(&trace_event_ida, __TRACE_LAST_TYPE,
+ TRACE_EVENT_TYPE_MAX, GFP_KERNEL);
+ if (next < 0)
return 0;
-
- if (e)
- *list = &e->list;
- else
- *list = &ftrace_event_list;
return next;
}
@@ -761,28 +745,10 @@ int register_trace_event(struct trace_event *event)
if (WARN_ON(!event->funcs))
goto out;
- INIT_LIST_HEAD(&event->list);
-
if (!event->type) {
- struct list_head *list = NULL;
-
- if (next_event_type > TRACE_EVENT_TYPE_MAX) {
-
- event->type = trace_search_list(&list);
- if (!event->type)
- goto out;
-
- } else {
-
- event->type = next_event_type++;
- list = &ftrace_event_list;
- }
-
- if (WARN_ON(ftrace_find_event(event->type)))
+ event->type = alloc_trace_event_type();
+ if (!event->type)
goto out;
-
- list_add_tail(&event->list, list);
-
} else if (WARN(event->type > __TRACE_LAST_TYPE,
"Need to add type to trace.h")) {
goto out;
@@ -819,7 +785,7 @@ EXPORT_SYMBOL_GPL(register_trace_event);
int __unregister_trace_event(struct trace_event *event)
{
hlist_del(&event->node);
- list_del(&event->list);
+ free_trace_event_type(event->type);
return 0;
}