Skip to content

Commit

Permalink
tracepoint: Remove unused API functions
Browse files Browse the repository at this point in the history 
After the following commit:

commit b75ef8b
Author: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date:   Wed Aug 10 15:18:39 2011 -0400

    Tracepoint: Dissociate from module mutex

The following functions became unnecessary:

- tracepoint_probe_register_noupdate,
- tracepoint_probe_unregister_noupdate,
- tracepoint_probe_update_all.

In fact, none of the in-kernel tracers, nor LTTng, nor SystemTAP use
them. Remove those.

Moreover, the functions:

- tracepoint_iter_start,
- tracepoint_iter_next,
- tracepoint_iter_stop,
- tracepoint_iter_reset.

are unused by in-kernel tracers, LTTng and SystemTAP. Remove those too.

Link: http://lkml.kernel.org/r/1395379142-2118-2-git-send-email-mathieu.desnoyers@efficios.com

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
  • Loading branch information
@compudj @rostedt
compudj authored and rostedt committed Mar 21, 2014
1 parent bc4c426 commit 0dea6d5
Show file tree
Hide file tree
Showing 2 changed files with 5 additions and 235 deletions.
18 changes: 0 additions & 18 deletions include/linux/tracepoint.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -48,12 +48,6 @@ extern int tracepoint_probe_register(const char *name, void *probe, void *data);
extern int
tracepoint_probe_unregister(const char *name, void *probe, void *data);

extern int tracepoint_probe_register_noupdate(const char *name, void *probe,
void *data);
extern int tracepoint_probe_unregister_noupdate(const char *name, void *probe,
void *data);
extern void tracepoint_probe_update_all(void);

#ifdef CONFIG_MODULES
struct tp_module {
struct list_head list;
Expand All @@ -62,18 +56,6 @@ struct tp_module {
};
#endif /* CONFIG_MODULES */

struct tracepoint_iter {
#ifdef CONFIG_MODULES
struct tp_module *module;
#endif /* CONFIG_MODULES */
struct tracepoint * const *tracepoint;
};

extern void tracepoint_iter_start(struct tracepoint_iter *iter);
extern void tracepoint_iter_next(struct tracepoint_iter *iter);
extern void tracepoint_iter_stop(struct tracepoint_iter *iter);
extern void tracepoint_iter_reset(struct tracepoint_iter *iter);

/*
* tracepoint_synchronize_unregister must be called between the last tracepoint
* probe unregistration and the end of module exit to make sure there is no
Expand Down
222 changes: 5 additions & 217 deletions kernel/tracepoint.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -67,10 +67,7 @@ struct tracepoint_entry {
};

struct tp_probes {
union {
struct rcu_head rcu;
struct list_head list;
} u;
struct rcu_head rcu;
struct tracepoint_func probes[0];
};

Expand All @@ -83,15 +80,15 @@ static inline void *allocate_probes(int count)

static void rcu_free_old_probes(struct rcu_head *head)
{
kfree(container_of(head, struct tp_probes, u.rcu));
kfree(container_of(head, struct tp_probes, rcu));
}

static inline void release_probes(struct tracepoint_func *old)
{
if (old) {
struct tp_probes *tp_probes = container_of(old,
struct tp_probes, probes[0]);
call_rcu_sched(&tp_probes->u.rcu, rcu_free_old_probes);
call_rcu_sched(&tp_probes->rcu, rcu_free_old_probes);
}
}

Expand Down Expand Up @@ -459,204 +456,11 @@ int tracepoint_probe_unregister(const char *name, void *probe, void *data)
}
EXPORT_SYMBOL_GPL(tracepoint_probe_unregister);

static LIST_HEAD(old_probes);
static int need_update;

static void tracepoint_add_old_probes(void *old)
{
need_update = 1;
if (old) {
struct tp_probes *tp_probes = container_of(old,
struct tp_probes, probes[0]);
list_add(&tp_probes->u.list, &old_probes);
}
}

/**
* tracepoint_probe_register_noupdate - register a probe but not connect
* @name: tracepoint name
* @probe: probe handler
* @data: probe private data
*
* caller must call tracepoint_probe_update_all()
*/
int tracepoint_probe_register_noupdate(const char *name, void *probe,
void *data)
{
struct tracepoint_func *old;

mutex_lock(&tracepoints_mutex);
old = tracepoint_add_probe(name, probe, data);
if (IS_ERR(old)) {
mutex_unlock(&tracepoints_mutex);
return PTR_ERR(old);
}
tracepoint_add_old_probes(old);
mutex_unlock(&tracepoints_mutex);
return 0;
}
EXPORT_SYMBOL_GPL(tracepoint_probe_register_noupdate);

/**
* tracepoint_probe_unregister_noupdate - remove a probe but not disconnect
* @name: tracepoint name
* @probe: probe function pointer
* @data: probe private data
*
* caller must call tracepoint_probe_update_all()
*/
int tracepoint_probe_unregister_noupdate(const char *name, void *probe,
void *data)
{
struct tracepoint_func *old;

mutex_lock(&tracepoints_mutex);
old = tracepoint_remove_probe(name, probe, data);
if (IS_ERR(old)) {
mutex_unlock(&tracepoints_mutex);
return PTR_ERR(old);
}
tracepoint_add_old_probes(old);
mutex_unlock(&tracepoints_mutex);
return 0;
}
EXPORT_SYMBOL_GPL(tracepoint_probe_unregister_noupdate);

/**
* tracepoint_probe_update_all - update tracepoints
*/
void tracepoint_probe_update_all(void)
{
LIST_HEAD(release_probes);
struct tp_probes *pos, *next;

mutex_lock(&tracepoints_mutex);
if (!need_update) {
mutex_unlock(&tracepoints_mutex);
return;
}
if (!list_empty(&old_probes))
list_replace_init(&old_probes, &release_probes);
need_update = 0;
tracepoint_update_probes();
mutex_unlock(&tracepoints_mutex);
list_for_each_entry_safe(pos, next, &release_probes, u.list) {
list_del(&pos->u.list);
call_rcu_sched(&pos->u.rcu, rcu_free_old_probes);
}
}
EXPORT_SYMBOL_GPL(tracepoint_probe_update_all);

/**
* tracepoint_get_iter_range - Get a next tracepoint iterator given a range.
* @tracepoint: current tracepoints (in), next tracepoint (out)
* @begin: beginning of the range
* @end: end of the range
*
* Returns whether a next tracepoint has been found (1) or not (0).
* Will return the first tracepoint in the range if the input tracepoint is
* NULL.
*/
static int tracepoint_get_iter_range(struct tracepoint * const **tracepoint,
struct tracepoint * const *begin, struct tracepoint * const *end)
{
if (!*tracepoint && begin != end) {
*tracepoint = begin;
return 1;
}
if (*tracepoint >= begin && *tracepoint < end)
return 1;
return 0;
}

#ifdef CONFIG_MODULES
static void tracepoint_get_iter(struct tracepoint_iter *iter)
{
int found = 0;
struct tp_module *iter_mod;

/* Core kernel tracepoints */
if (!iter->module) {
found = tracepoint_get_iter_range(&iter->tracepoint,
__start___tracepoints_ptrs,
__stop___tracepoints_ptrs);
if (found)
goto end;
}
/* Tracepoints in modules */
mutex_lock(&tracepoints_mutex);
list_for_each_entry(iter_mod, &tracepoint_module_list, list) {
/*
* Sorted module list
*/
if (iter_mod < iter->module)
continue;
else if (iter_mod > iter->module)
iter->tracepoint = NULL;
found = tracepoint_get_iter_range(&iter->tracepoint,
iter_mod->tracepoints_ptrs,
iter_mod->tracepoints_ptrs
+ iter_mod->num_tracepoints);
if (found) {
iter->module = iter_mod;
break;
}
}
mutex_unlock(&tracepoints_mutex);
end:
if (!found)
tracepoint_iter_reset(iter);
}
#else /* CONFIG_MODULES */
static void tracepoint_get_iter(struct tracepoint_iter *iter)
{
int found = 0;

/* Core kernel tracepoints */
found = tracepoint_get_iter_range(&iter->tracepoint,
__start___tracepoints_ptrs,
__stop___tracepoints_ptrs);
if (!found)
tracepoint_iter_reset(iter);
}
#endif /* CONFIG_MODULES */

void tracepoint_iter_start(struct tracepoint_iter *iter)
{
tracepoint_get_iter(iter);
}
EXPORT_SYMBOL_GPL(tracepoint_iter_start);

void tracepoint_iter_next(struct tracepoint_iter *iter)
{
iter->tracepoint++;
/*
* iter->tracepoint may be invalid because we blindly incremented it.
* Make sure it is valid by marshalling on the tracepoints, getting the
* tracepoints from following modules if necessary.
*/
tracepoint_get_iter(iter);
}
EXPORT_SYMBOL_GPL(tracepoint_iter_next);

void tracepoint_iter_stop(struct tracepoint_iter *iter)
{
}
EXPORT_SYMBOL_GPL(tracepoint_iter_stop);

void tracepoint_iter_reset(struct tracepoint_iter *iter)
{
#ifdef CONFIG_MODULES
iter->module = NULL;
#endif /* CONFIG_MODULES */
iter->tracepoint = NULL;
}
EXPORT_SYMBOL_GPL(tracepoint_iter_reset);

#ifdef CONFIG_MODULES
static int tracepoint_module_coming(struct module *mod)
{
struct tp_module *tp_mod, *iter;
struct tp_module *tp_mod;
int ret = 0;

if (!mod->num_tracepoints)
Expand All @@ -677,23 +481,7 @@ static int tracepoint_module_coming(struct module *mod)
}
tp_mod->num_tracepoints = mod->num_tracepoints;
tp_mod->tracepoints_ptrs = mod->tracepoints_ptrs;

/*
* tracepoint_module_list is kept sorted by struct module pointer
* address for iteration on tracepoints from a seq_file that can release
* the mutex between calls.
*/
list_for_each_entry_reverse(iter, &tracepoint_module_list, list) {
BUG_ON(iter == tp_mod); /* Should never be in the list twice */
if (iter < tp_mod) {
/* We belong to the location right after iter. */
list_add(&tp_mod->list, &iter->list);
goto module_added;
}
}
/* We belong to the beginning of the list */
list_add(&tp_mod->list, &tracepoint_module_list);
module_added:
list_add_tail(&tp_mod->list, &tracepoint_module_list);
tracepoint_update_probe_range(mod->tracepoints_ptrs,
mod->tracepoints_ptrs + mod->num_tracepoints);
end:
Expand Down

0 comments on commit 0dea6d5

Please sign in to comment.