linux-sg2042/kernel/trace/trace_stat.c

327 lines
7.3 KiB
C
Raw Normal View History

tracing/ftrace: provide the base infrastructure for histogram tracing Impact: extend the tracing API The goal of this patch is to normalize and make more easy the implementation of statistical (histogram) tracing. It implements a trace_stat file into the /debugfs/tracing directory where one can print a one-shot output of statistics/histogram entries. A tracer has to provide two basic iterator callbacks: stat_start() => the first entry stat_next(prev, idx) => the next one. Note that it is adapted for arrays or hash tables or lists.... since it provides a pointer to the previous entry and the current index of the iterator. These two callbacks are called to get a snapshot of the statistics at each opening of the trace_stat file because. The values are so updated between two "cat trace_stat". And the tracer is free to lock its datas during the iteration to keep consistent values. Since it is almost always interesting to sort statisticals values to address the problems by priority, this infrastructure provides a "sorting" of the stat entries too if desired. A tracer has just to provide a stat_cmp callback to compare two entries and the stat tracing infrastructure will build a sorted list of the given entries. A last callback, called stat_headers, can be implemented by a tracer to output headers on its trace. If one of these callbacks is changed on runtime, it just have to signal it to the stat tracing API by calling the init_tracer_stat() helper. Changes in V2: - Fix a memory leak if the user opens multiple times the trace_stat file without closing it. Now we always free our list before rebuilding it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29 12:44:51 +08:00
/*
* Infrastructure for statistic tracing (histogram output).
*
* Copyright (C) 2008 Frederic Weisbecker <fweisbec@gmail.com>
*
* Based on the code from trace_branch.c which is
* Copyright (C) 2008 Steven Rostedt <srostedt@redhat.com>
*
*/
#include <linux/list.h>
#include <linux/debugfs.h>
#include "trace_stat.h"
tracing/ftrace: provide the base infrastructure for histogram tracing Impact: extend the tracing API The goal of this patch is to normalize and make more easy the implementation of statistical (histogram) tracing. It implements a trace_stat file into the /debugfs/tracing directory where one can print a one-shot output of statistics/histogram entries. A tracer has to provide two basic iterator callbacks: stat_start() => the first entry stat_next(prev, idx) => the next one. Note that it is adapted for arrays or hash tables or lists.... since it provides a pointer to the previous entry and the current index of the iterator. These two callbacks are called to get a snapshot of the statistics at each opening of the trace_stat file because. The values are so updated between two "cat trace_stat". And the tracer is free to lock its datas during the iteration to keep consistent values. Since it is almost always interesting to sort statisticals values to address the problems by priority, this infrastructure provides a "sorting" of the stat entries too if desired. A tracer has just to provide a stat_cmp callback to compare two entries and the stat tracing infrastructure will build a sorted list of the given entries. A last callback, called stat_headers, can be implemented by a tracer to output headers on its trace. If one of these callbacks is changed on runtime, it just have to signal it to the stat tracing API by calling the init_tracer_stat() helper. Changes in V2: - Fix a memory leak if the user opens multiple times the trace_stat file without closing it. Now we always free our list before rebuilding it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29 12:44:51 +08:00
#include "trace.h"
/* List of stat entries from a tracer */
struct trace_stat_list {
struct list_head list;
void *stat;
tracing/ftrace: provide the base infrastructure for histogram tracing Impact: extend the tracing API The goal of this patch is to normalize and make more easy the implementation of statistical (histogram) tracing. It implements a trace_stat file into the /debugfs/tracing directory where one can print a one-shot output of statistics/histogram entries. A tracer has to provide two basic iterator callbacks: stat_start() => the first entry stat_next(prev, idx) => the next one. Note that it is adapted for arrays or hash tables or lists.... since it provides a pointer to the previous entry and the current index of the iterator. These two callbacks are called to get a snapshot of the statistics at each opening of the trace_stat file because. The values are so updated between two "cat trace_stat". And the tracer is free to lock its datas during the iteration to keep consistent values. Since it is almost always interesting to sort statisticals values to address the problems by priority, this infrastructure provides a "sorting" of the stat entries too if desired. A tracer has just to provide a stat_cmp callback to compare two entries and the stat tracing infrastructure will build a sorted list of the given entries. A last callback, called stat_headers, can be implemented by a tracer to output headers on its trace. If one of these callbacks is changed on runtime, it just have to signal it to the stat tracing API by calling the init_tracer_stat() helper. Changes in V2: - Fix a memory leak if the user opens multiple times the trace_stat file without closing it. Now we always free our list before rebuilding it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29 12:44:51 +08:00
};
/* A stat session is the stats output in one file */
struct tracer_stat_session {
struct list_head session_list;
struct tracer_stat *ts;
struct list_head stat_list;
struct mutex stat_mutex;
struct dentry *file;
};
tracing/ftrace: provide the base infrastructure for histogram tracing Impact: extend the tracing API The goal of this patch is to normalize and make more easy the implementation of statistical (histogram) tracing. It implements a trace_stat file into the /debugfs/tracing directory where one can print a one-shot output of statistics/histogram entries. A tracer has to provide two basic iterator callbacks: stat_start() => the first entry stat_next(prev, idx) => the next one. Note that it is adapted for arrays or hash tables or lists.... since it provides a pointer to the previous entry and the current index of the iterator. These two callbacks are called to get a snapshot of the statistics at each opening of the trace_stat file because. The values are so updated between two "cat trace_stat". And the tracer is free to lock its datas during the iteration to keep consistent values. Since it is almost always interesting to sort statisticals values to address the problems by priority, this infrastructure provides a "sorting" of the stat entries too if desired. A tracer has just to provide a stat_cmp callback to compare two entries and the stat tracing infrastructure will build a sorted list of the given entries. A last callback, called stat_headers, can be implemented by a tracer to output headers on its trace. If one of these callbacks is changed on runtime, it just have to signal it to the stat tracing API by calling the init_tracer_stat() helper. Changes in V2: - Fix a memory leak if the user opens multiple times the trace_stat file without closing it. Now we always free our list before rebuilding it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29 12:44:51 +08:00
/* All of the sessions currently in use. Each stat file embed one session */
static LIST_HEAD(all_stat_sessions);
static DEFINE_MUTEX(all_stat_sessions_mutex);
/* The root directory for all stat files */
static struct dentry *stat_dir;
tracing/ftrace: provide the base infrastructure for histogram tracing Impact: extend the tracing API The goal of this patch is to normalize and make more easy the implementation of statistical (histogram) tracing. It implements a trace_stat file into the /debugfs/tracing directory where one can print a one-shot output of statistics/histogram entries. A tracer has to provide two basic iterator callbacks: stat_start() => the first entry stat_next(prev, idx) => the next one. Note that it is adapted for arrays or hash tables or lists.... since it provides a pointer to the previous entry and the current index of the iterator. These two callbacks are called to get a snapshot of the statistics at each opening of the trace_stat file because. The values are so updated between two "cat trace_stat". And the tracer is free to lock its datas during the iteration to keep consistent values. Since it is almost always interesting to sort statisticals values to address the problems by priority, this infrastructure provides a "sorting" of the stat entries too if desired. A tracer has just to provide a stat_cmp callback to compare two entries and the stat tracing infrastructure will build a sorted list of the given entries. A last callback, called stat_headers, can be implemented by a tracer to output headers on its trace. If one of these callbacks is changed on runtime, it just have to signal it to the stat tracing API by calling the init_tracer_stat() helper. Changes in V2: - Fix a memory leak if the user opens multiple times the trace_stat file without closing it. Now we always free our list before rebuilding it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29 12:44:51 +08:00
static void reset_stat_session(struct tracer_stat_session *session)
tracing/ftrace: provide the base infrastructure for histogram tracing Impact: extend the tracing API The goal of this patch is to normalize and make more easy the implementation of statistical (histogram) tracing. It implements a trace_stat file into the /debugfs/tracing directory where one can print a one-shot output of statistics/histogram entries. A tracer has to provide two basic iterator callbacks: stat_start() => the first entry stat_next(prev, idx) => the next one. Note that it is adapted for arrays or hash tables or lists.... since it provides a pointer to the previous entry and the current index of the iterator. These two callbacks are called to get a snapshot of the statistics at each opening of the trace_stat file because. The values are so updated between two "cat trace_stat". And the tracer is free to lock its datas during the iteration to keep consistent values. Since it is almost always interesting to sort statisticals values to address the problems by priority, this infrastructure provides a "sorting" of the stat entries too if desired. A tracer has just to provide a stat_cmp callback to compare two entries and the stat tracing infrastructure will build a sorted list of the given entries. A last callback, called stat_headers, can be implemented by a tracer to output headers on its trace. If one of these callbacks is changed on runtime, it just have to signal it to the stat tracing API by calling the init_tracer_stat() helper. Changes in V2: - Fix a memory leak if the user opens multiple times the trace_stat file without closing it. Now we always free our list before rebuilding it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29 12:44:51 +08:00
{
struct trace_stat_list *node, *next;
tracing/ftrace: provide the base infrastructure for histogram tracing Impact: extend the tracing API The goal of this patch is to normalize and make more easy the implementation of statistical (histogram) tracing. It implements a trace_stat file into the /debugfs/tracing directory where one can print a one-shot output of statistics/histogram entries. A tracer has to provide two basic iterator callbacks: stat_start() => the first entry stat_next(prev, idx) => the next one. Note that it is adapted for arrays or hash tables or lists.... since it provides a pointer to the previous entry and the current index of the iterator. These two callbacks are called to get a snapshot of the statistics at each opening of the trace_stat file because. The values are so updated between two "cat trace_stat". And the tracer is free to lock its datas during the iteration to keep consistent values. Since it is almost always interesting to sort statisticals values to address the problems by priority, this infrastructure provides a "sorting" of the stat entries too if desired. A tracer has just to provide a stat_cmp callback to compare two entries and the stat tracing infrastructure will build a sorted list of the given entries. A last callback, called stat_headers, can be implemented by a tracer to output headers on its trace. If one of these callbacks is changed on runtime, it just have to signal it to the stat tracing API by calling the init_tracer_stat() helper. Changes in V2: - Fix a memory leak if the user opens multiple times the trace_stat file without closing it. Now we always free our list before rebuilding it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29 12:44:51 +08:00
list_for_each_entry_safe(node, next, &session->stat_list, list)
tracing/ftrace: provide the base infrastructure for histogram tracing Impact: extend the tracing API The goal of this patch is to normalize and make more easy the implementation of statistical (histogram) tracing. It implements a trace_stat file into the /debugfs/tracing directory where one can print a one-shot output of statistics/histogram entries. A tracer has to provide two basic iterator callbacks: stat_start() => the first entry stat_next(prev, idx) => the next one. Note that it is adapted for arrays or hash tables or lists.... since it provides a pointer to the previous entry and the current index of the iterator. These two callbacks are called to get a snapshot of the statistics at each opening of the trace_stat file because. The values are so updated between two "cat trace_stat". And the tracer is free to lock its datas during the iteration to keep consistent values. Since it is almost always interesting to sort statisticals values to address the problems by priority, this infrastructure provides a "sorting" of the stat entries too if desired. A tracer has just to provide a stat_cmp callback to compare two entries and the stat tracing infrastructure will build a sorted list of the given entries. A last callback, called stat_headers, can be implemented by a tracer to output headers on its trace. If one of these callbacks is changed on runtime, it just have to signal it to the stat tracing API by calling the init_tracer_stat() helper. Changes in V2: - Fix a memory leak if the user opens multiple times the trace_stat file without closing it. Now we always free our list before rebuilding it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29 12:44:51 +08:00
kfree(node);
INIT_LIST_HEAD(&session->stat_list);
tracing/ftrace: provide the base infrastructure for histogram tracing Impact: extend the tracing API The goal of this patch is to normalize and make more easy the implementation of statistical (histogram) tracing. It implements a trace_stat file into the /debugfs/tracing directory where one can print a one-shot output of statistics/histogram entries. A tracer has to provide two basic iterator callbacks: stat_start() => the first entry stat_next(prev, idx) => the next one. Note that it is adapted for arrays or hash tables or lists.... since it provides a pointer to the previous entry and the current index of the iterator. These two callbacks are called to get a snapshot of the statistics at each opening of the trace_stat file because. The values are so updated between two "cat trace_stat". And the tracer is free to lock its datas during the iteration to keep consistent values. Since it is almost always interesting to sort statisticals values to address the problems by priority, this infrastructure provides a "sorting" of the stat entries too if desired. A tracer has just to provide a stat_cmp callback to compare two entries and the stat tracing infrastructure will build a sorted list of the given entries. A last callback, called stat_headers, can be implemented by a tracer to output headers on its trace. If one of these callbacks is changed on runtime, it just have to signal it to the stat tracing API by calling the init_tracer_stat() helper. Changes in V2: - Fix a memory leak if the user opens multiple times the trace_stat file without closing it. Now we always free our list before rebuilding it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29 12:44:51 +08:00
}
static void destroy_session(struct tracer_stat_session *session)
tracing/ftrace: provide the base infrastructure for histogram tracing Impact: extend the tracing API The goal of this patch is to normalize and make more easy the implementation of statistical (histogram) tracing. It implements a trace_stat file into the /debugfs/tracing directory where one can print a one-shot output of statistics/histogram entries. A tracer has to provide two basic iterator callbacks: stat_start() => the first entry stat_next(prev, idx) => the next one. Note that it is adapted for arrays or hash tables or lists.... since it provides a pointer to the previous entry and the current index of the iterator. These two callbacks are called to get a snapshot of the statistics at each opening of the trace_stat file because. The values are so updated between two "cat trace_stat". And the tracer is free to lock its datas during the iteration to keep consistent values. Since it is almost always interesting to sort statisticals values to address the problems by priority, this infrastructure provides a "sorting" of the stat entries too if desired. A tracer has just to provide a stat_cmp callback to compare two entries and the stat tracing infrastructure will build a sorted list of the given entries. A last callback, called stat_headers, can be implemented by a tracer to output headers on its trace. If one of these callbacks is changed on runtime, it just have to signal it to the stat tracing API by calling the init_tracer_stat() helper. Changes in V2: - Fix a memory leak if the user opens multiple times the trace_stat file without closing it. Now we always free our list before rebuilding it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29 12:44:51 +08:00
{
debugfs_remove(session->file);
reset_stat_session(session);
mutex_destroy(&session->stat_mutex);
kfree(session);
}
tracing/ftrace: provide the base infrastructure for histogram tracing Impact: extend the tracing API The goal of this patch is to normalize and make more easy the implementation of statistical (histogram) tracing. It implements a trace_stat file into the /debugfs/tracing directory where one can print a one-shot output of statistics/histogram entries. A tracer has to provide two basic iterator callbacks: stat_start() => the first entry stat_next(prev, idx) => the next one. Note that it is adapted for arrays or hash tables or lists.... since it provides a pointer to the previous entry and the current index of the iterator. These two callbacks are called to get a snapshot of the statistics at each opening of the trace_stat file because. The values are so updated between two "cat trace_stat". And the tracer is free to lock its datas during the iteration to keep consistent values. Since it is almost always interesting to sort statisticals values to address the problems by priority, this infrastructure provides a "sorting" of the stat entries too if desired. A tracer has just to provide a stat_cmp callback to compare two entries and the stat tracing infrastructure will build a sorted list of the given entries. A last callback, called stat_headers, can be implemented by a tracer to output headers on its trace. If one of these callbacks is changed on runtime, it just have to signal it to the stat tracing API by calling the init_tracer_stat() helper. Changes in V2: - Fix a memory leak if the user opens multiple times the trace_stat file without closing it. Now we always free our list before rebuilding it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29 12:44:51 +08:00
/*
* For tracers that don't provide a stat_cmp callback.
* This one will force an immediate insertion on tail of
* the list.
*/
static int dummy_cmp(void *p1, void *p2)
{
return 1;
}
/*
* Initialize the stat list at each trace_stat file opening.
* All of these copies and sorting are required on all opening
* since the stats could have changed between two file sessions.
*/
static int stat_seq_init(struct tracer_stat_session *session)
tracing/ftrace: provide the base infrastructure for histogram tracing Impact: extend the tracing API The goal of this patch is to normalize and make more easy the implementation of statistical (histogram) tracing. It implements a trace_stat file into the /debugfs/tracing directory where one can print a one-shot output of statistics/histogram entries. A tracer has to provide two basic iterator callbacks: stat_start() => the first entry stat_next(prev, idx) => the next one. Note that it is adapted for arrays or hash tables or lists.... since it provides a pointer to the previous entry and the current index of the iterator. These two callbacks are called to get a snapshot of the statistics at each opening of the trace_stat file because. The values are so updated between two "cat trace_stat". And the tracer is free to lock its datas during the iteration to keep consistent values. Since it is almost always interesting to sort statisticals values to address the problems by priority, this infrastructure provides a "sorting" of the stat entries too if desired. A tracer has just to provide a stat_cmp callback to compare two entries and the stat tracing infrastructure will build a sorted list of the given entries. A last callback, called stat_headers, can be implemented by a tracer to output headers on its trace. If one of these callbacks is changed on runtime, it just have to signal it to the stat tracing API by calling the init_tracer_stat() helper. Changes in V2: - Fix a memory leak if the user opens multiple times the trace_stat file without closing it. Now we always free our list before rebuilding it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29 12:44:51 +08:00
{
struct trace_stat_list *iter_entry, *new_entry;
struct tracer_stat *ts = session->ts;
void *stat;
tracing/ftrace: provide the base infrastructure for histogram tracing Impact: extend the tracing API The goal of this patch is to normalize and make more easy the implementation of statistical (histogram) tracing. It implements a trace_stat file into the /debugfs/tracing directory where one can print a one-shot output of statistics/histogram entries. A tracer has to provide two basic iterator callbacks: stat_start() => the first entry stat_next(prev, idx) => the next one. Note that it is adapted for arrays or hash tables or lists.... since it provides a pointer to the previous entry and the current index of the iterator. These two callbacks are called to get a snapshot of the statistics at each opening of the trace_stat file because. The values are so updated between two "cat trace_stat". And the tracer is free to lock its datas during the iteration to keep consistent values. Since it is almost always interesting to sort statisticals values to address the problems by priority, this infrastructure provides a "sorting" of the stat entries too if desired. A tracer has just to provide a stat_cmp callback to compare two entries and the stat tracing infrastructure will build a sorted list of the given entries. A last callback, called stat_headers, can be implemented by a tracer to output headers on its trace. If one of these callbacks is changed on runtime, it just have to signal it to the stat tracing API by calling the init_tracer_stat() helper. Changes in V2: - Fix a memory leak if the user opens multiple times the trace_stat file without closing it. Now we always free our list before rebuilding it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29 12:44:51 +08:00
int ret = 0;
int i;
mutex_lock(&session->stat_mutex);
reset_stat_session(session);
tracing/ftrace: provide the base infrastructure for histogram tracing Impact: extend the tracing API The goal of this patch is to normalize and make more easy the implementation of statistical (histogram) tracing. It implements a trace_stat file into the /debugfs/tracing directory where one can print a one-shot output of statistics/histogram entries. A tracer has to provide two basic iterator callbacks: stat_start() => the first entry stat_next(prev, idx) => the next one. Note that it is adapted for arrays or hash tables or lists.... since it provides a pointer to the previous entry and the current index of the iterator. These two callbacks are called to get a snapshot of the statistics at each opening of the trace_stat file because. The values are so updated between two "cat trace_stat". And the tracer is free to lock its datas during the iteration to keep consistent values. Since it is almost always interesting to sort statisticals values to address the problems by priority, this infrastructure provides a "sorting" of the stat entries too if desired. A tracer has just to provide a stat_cmp callback to compare two entries and the stat tracing infrastructure will build a sorted list of the given entries. A last callback, called stat_headers, can be implemented by a tracer to output headers on its trace. If one of these callbacks is changed on runtime, it just have to signal it to the stat tracing API by calling the init_tracer_stat() helper. Changes in V2: - Fix a memory leak if the user opens multiple times the trace_stat file without closing it. Now we always free our list before rebuilding it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29 12:44:51 +08:00
if (!ts->stat_cmp)
ts->stat_cmp = dummy_cmp;
tracing/ftrace: provide the base infrastructure for histogram tracing Impact: extend the tracing API The goal of this patch is to normalize and make more easy the implementation of statistical (histogram) tracing. It implements a trace_stat file into the /debugfs/tracing directory where one can print a one-shot output of statistics/histogram entries. A tracer has to provide two basic iterator callbacks: stat_start() => the first entry stat_next(prev, idx) => the next one. Note that it is adapted for arrays or hash tables or lists.... since it provides a pointer to the previous entry and the current index of the iterator. These two callbacks are called to get a snapshot of the statistics at each opening of the trace_stat file because. The values are so updated between two "cat trace_stat". And the tracer is free to lock its datas during the iteration to keep consistent values. Since it is almost always interesting to sort statisticals values to address the problems by priority, this infrastructure provides a "sorting" of the stat entries too if desired. A tracer has just to provide a stat_cmp callback to compare two entries and the stat tracing infrastructure will build a sorted list of the given entries. A last callback, called stat_headers, can be implemented by a tracer to output headers on its trace. If one of these callbacks is changed on runtime, it just have to signal it to the stat tracing API by calling the init_tracer_stat() helper. Changes in V2: - Fix a memory leak if the user opens multiple times the trace_stat file without closing it. Now we always free our list before rebuilding it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29 12:44:51 +08:00
stat = ts->stat_start(ts);
if (!stat)
goto exit;
tracing/ftrace: provide the base infrastructure for histogram tracing Impact: extend the tracing API The goal of this patch is to normalize and make more easy the implementation of statistical (histogram) tracing. It implements a trace_stat file into the /debugfs/tracing directory where one can print a one-shot output of statistics/histogram entries. A tracer has to provide two basic iterator callbacks: stat_start() => the first entry stat_next(prev, idx) => the next one. Note that it is adapted for arrays or hash tables or lists.... since it provides a pointer to the previous entry and the current index of the iterator. These two callbacks are called to get a snapshot of the statistics at each opening of the trace_stat file because. The values are so updated between two "cat trace_stat". And the tracer is free to lock its datas during the iteration to keep consistent values. Since it is almost always interesting to sort statisticals values to address the problems by priority, this infrastructure provides a "sorting" of the stat entries too if desired. A tracer has just to provide a stat_cmp callback to compare two entries and the stat tracing infrastructure will build a sorted list of the given entries. A last callback, called stat_headers, can be implemented by a tracer to output headers on its trace. If one of these callbacks is changed on runtime, it just have to signal it to the stat tracing API by calling the init_tracer_stat() helper. Changes in V2: - Fix a memory leak if the user opens multiple times the trace_stat file without closing it. Now we always free our list before rebuilding it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29 12:44:51 +08:00
/*
* The first entry. Actually this is the second, but the first
* one (the stat_list head) is pointless.
*/
new_entry = kmalloc(sizeof(struct trace_stat_list), GFP_KERNEL);
if (!new_entry) {
ret = -ENOMEM;
goto exit;
}
INIT_LIST_HEAD(&new_entry->list);
list_add(&new_entry->list, &session->stat_list);
new_entry->stat = stat;
tracing/ftrace: provide the base infrastructure for histogram tracing Impact: extend the tracing API The goal of this patch is to normalize and make more easy the implementation of statistical (histogram) tracing. It implements a trace_stat file into the /debugfs/tracing directory where one can print a one-shot output of statistics/histogram entries. A tracer has to provide two basic iterator callbacks: stat_start() => the first entry stat_next(prev, idx) => the next one. Note that it is adapted for arrays or hash tables or lists.... since it provides a pointer to the previous entry and the current index of the iterator. These two callbacks are called to get a snapshot of the statistics at each opening of the trace_stat file because. The values are so updated between two "cat trace_stat". And the tracer is free to lock its datas during the iteration to keep consistent values. Since it is almost always interesting to sort statisticals values to address the problems by priority, this infrastructure provides a "sorting" of the stat entries too if desired. A tracer has just to provide a stat_cmp callback to compare two entries and the stat tracing infrastructure will build a sorted list of the given entries. A last callback, called stat_headers, can be implemented by a tracer to output headers on its trace. If one of these callbacks is changed on runtime, it just have to signal it to the stat tracing API by calling the init_tracer_stat() helper. Changes in V2: - Fix a memory leak if the user opens multiple times the trace_stat file without closing it. Now we always free our list before rebuilding it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29 12:44:51 +08:00
/*
* Iterate over the tracer stat entries and store them in a sorted
* list.
*/
for (i = 1; ; i++) {
stat = ts->stat_next(stat, i);
/* End of insertion */
if (!stat)
break;
tracing/ftrace: provide the base infrastructure for histogram tracing Impact: extend the tracing API The goal of this patch is to normalize and make more easy the implementation of statistical (histogram) tracing. It implements a trace_stat file into the /debugfs/tracing directory where one can print a one-shot output of statistics/histogram entries. A tracer has to provide two basic iterator callbacks: stat_start() => the first entry stat_next(prev, idx) => the next one. Note that it is adapted for arrays or hash tables or lists.... since it provides a pointer to the previous entry and the current index of the iterator. These two callbacks are called to get a snapshot of the statistics at each opening of the trace_stat file because. The values are so updated between two "cat trace_stat". And the tracer is free to lock its datas during the iteration to keep consistent values. Since it is almost always interesting to sort statisticals values to address the problems by priority, this infrastructure provides a "sorting" of the stat entries too if desired. A tracer has just to provide a stat_cmp callback to compare two entries and the stat tracing infrastructure will build a sorted list of the given entries. A last callback, called stat_headers, can be implemented by a tracer to output headers on its trace. If one of these callbacks is changed on runtime, it just have to signal it to the stat tracing API by calling the init_tracer_stat() helper. Changes in V2: - Fix a memory leak if the user opens multiple times the trace_stat file without closing it. Now we always free our list before rebuilding it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29 12:44:51 +08:00
new_entry = kmalloc(sizeof(struct trace_stat_list), GFP_KERNEL);
if (!new_entry) {
ret = -ENOMEM;
goto exit_free_list;
}
INIT_LIST_HEAD(&new_entry->list);
new_entry->stat = stat;
tracing/ftrace: provide the base infrastructure for histogram tracing Impact: extend the tracing API The goal of this patch is to normalize and make more easy the implementation of statistical (histogram) tracing. It implements a trace_stat file into the /debugfs/tracing directory where one can print a one-shot output of statistics/histogram entries. A tracer has to provide two basic iterator callbacks: stat_start() => the first entry stat_next(prev, idx) => the next one. Note that it is adapted for arrays or hash tables or lists.... since it provides a pointer to the previous entry and the current index of the iterator. These two callbacks are called to get a snapshot of the statistics at each opening of the trace_stat file because. The values are so updated between two "cat trace_stat". And the tracer is free to lock its datas during the iteration to keep consistent values. Since it is almost always interesting to sort statisticals values to address the problems by priority, this infrastructure provides a "sorting" of the stat entries too if desired. A tracer has just to provide a stat_cmp callback to compare two entries and the stat tracing infrastructure will build a sorted list of the given entries. A last callback, called stat_headers, can be implemented by a tracer to output headers on its trace. If one of these callbacks is changed on runtime, it just have to signal it to the stat tracing API by calling the init_tracer_stat() helper. Changes in V2: - Fix a memory leak if the user opens multiple times the trace_stat file without closing it. Now we always free our list before rebuilding it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29 12:44:51 +08:00
list_for_each_entry_reverse(iter_entry, &session->stat_list,
list) {
tracing/ftrace: provide the base infrastructure for histogram tracing Impact: extend the tracing API The goal of this patch is to normalize and make more easy the implementation of statistical (histogram) tracing. It implements a trace_stat file into the /debugfs/tracing directory where one can print a one-shot output of statistics/histogram entries. A tracer has to provide two basic iterator callbacks: stat_start() => the first entry stat_next(prev, idx) => the next one. Note that it is adapted for arrays or hash tables or lists.... since it provides a pointer to the previous entry and the current index of the iterator. These two callbacks are called to get a snapshot of the statistics at each opening of the trace_stat file because. The values are so updated between two "cat trace_stat". And the tracer is free to lock its datas during the iteration to keep consistent values. Since it is almost always interesting to sort statisticals values to address the problems by priority, this infrastructure provides a "sorting" of the stat entries too if desired. A tracer has just to provide a stat_cmp callback to compare two entries and the stat tracing infrastructure will build a sorted list of the given entries. A last callback, called stat_headers, can be implemented by a tracer to output headers on its trace. If one of these callbacks is changed on runtime, it just have to signal it to the stat tracing API by calling the init_tracer_stat() helper. Changes in V2: - Fix a memory leak if the user opens multiple times the trace_stat file without closing it. Now we always free our list before rebuilding it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29 12:44:51 +08:00
/* Insertion with a descendent sorting */
if (ts->stat_cmp(iter_entry->stat,
new_entry->stat) >= 0) {
tracing/ftrace: provide the base infrastructure for histogram tracing Impact: extend the tracing API The goal of this patch is to normalize and make more easy the implementation of statistical (histogram) tracing. It implements a trace_stat file into the /debugfs/tracing directory where one can print a one-shot output of statistics/histogram entries. A tracer has to provide two basic iterator callbacks: stat_start() => the first entry stat_next(prev, idx) => the next one. Note that it is adapted for arrays or hash tables or lists.... since it provides a pointer to the previous entry and the current index of the iterator. These two callbacks are called to get a snapshot of the statistics at each opening of the trace_stat file because. The values are so updated between two "cat trace_stat". And the tracer is free to lock its datas during the iteration to keep consistent values. Since it is almost always interesting to sort statisticals values to address the problems by priority, this infrastructure provides a "sorting" of the stat entries too if desired. A tracer has just to provide a stat_cmp callback to compare two entries and the stat tracing infrastructure will build a sorted list of the given entries. A last callback, called stat_headers, can be implemented by a tracer to output headers on its trace. If one of these callbacks is changed on runtime, it just have to signal it to the stat tracing API by calling the init_tracer_stat() helper. Changes in V2: - Fix a memory leak if the user opens multiple times the trace_stat file without closing it. Now we always free our list before rebuilding it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29 12:44:51 +08:00
list_add(&new_entry->list, &iter_entry->list);
break;
}
}
/* The current larger value */
if (list_empty(&new_entry->list))
list_add(&new_entry->list, &session->stat_list);
tracing/ftrace: provide the base infrastructure for histogram tracing Impact: extend the tracing API The goal of this patch is to normalize and make more easy the implementation of statistical (histogram) tracing. It implements a trace_stat file into the /debugfs/tracing directory where one can print a one-shot output of statistics/histogram entries. A tracer has to provide two basic iterator callbacks: stat_start() => the first entry stat_next(prev, idx) => the next one. Note that it is adapted for arrays or hash tables or lists.... since it provides a pointer to the previous entry and the current index of the iterator. These two callbacks are called to get a snapshot of the statistics at each opening of the trace_stat file because. The values are so updated between two "cat trace_stat". And the tracer is free to lock its datas during the iteration to keep consistent values. Since it is almost always interesting to sort statisticals values to address the problems by priority, this infrastructure provides a "sorting" of the stat entries too if desired. A tracer has just to provide a stat_cmp callback to compare two entries and the stat tracing infrastructure will build a sorted list of the given entries. A last callback, called stat_headers, can be implemented by a tracer to output headers on its trace. If one of these callbacks is changed on runtime, it just have to signal it to the stat tracing API by calling the init_tracer_stat() helper. Changes in V2: - Fix a memory leak if the user opens multiple times the trace_stat file without closing it. Now we always free our list before rebuilding it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29 12:44:51 +08:00
}
exit:
mutex_unlock(&session->stat_mutex);
tracing/ftrace: provide the base infrastructure for histogram tracing Impact: extend the tracing API The goal of this patch is to normalize and make more easy the implementation of statistical (histogram) tracing. It implements a trace_stat file into the /debugfs/tracing directory where one can print a one-shot output of statistics/histogram entries. A tracer has to provide two basic iterator callbacks: stat_start() => the first entry stat_next(prev, idx) => the next one. Note that it is adapted for arrays or hash tables or lists.... since it provides a pointer to the previous entry and the current index of the iterator. These two callbacks are called to get a snapshot of the statistics at each opening of the trace_stat file because. The values are so updated between two "cat trace_stat". And the tracer is free to lock its datas during the iteration to keep consistent values. Since it is almost always interesting to sort statisticals values to address the problems by priority, this infrastructure provides a "sorting" of the stat entries too if desired. A tracer has just to provide a stat_cmp callback to compare two entries and the stat tracing infrastructure will build a sorted list of the given entries. A last callback, called stat_headers, can be implemented by a tracer to output headers on its trace. If one of these callbacks is changed on runtime, it just have to signal it to the stat tracing API by calling the init_tracer_stat() helper. Changes in V2: - Fix a memory leak if the user opens multiple times the trace_stat file without closing it. Now we always free our list before rebuilding it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29 12:44:51 +08:00
return ret;
exit_free_list:
reset_stat_session(session);
mutex_unlock(&session->stat_mutex);
tracing/ftrace: provide the base infrastructure for histogram tracing Impact: extend the tracing API The goal of this patch is to normalize and make more easy the implementation of statistical (histogram) tracing. It implements a trace_stat file into the /debugfs/tracing directory where one can print a one-shot output of statistics/histogram entries. A tracer has to provide two basic iterator callbacks: stat_start() => the first entry stat_next(prev, idx) => the next one. Note that it is adapted for arrays or hash tables or lists.... since it provides a pointer to the previous entry and the current index of the iterator. These two callbacks are called to get a snapshot of the statistics at each opening of the trace_stat file because. The values are so updated between two "cat trace_stat". And the tracer is free to lock its datas during the iteration to keep consistent values. Since it is almost always interesting to sort statisticals values to address the problems by priority, this infrastructure provides a "sorting" of the stat entries too if desired. A tracer has just to provide a stat_cmp callback to compare two entries and the stat tracing infrastructure will build a sorted list of the given entries. A last callback, called stat_headers, can be implemented by a tracer to output headers on its trace. If one of these callbacks is changed on runtime, it just have to signal it to the stat tracing API by calling the init_tracer_stat() helper. Changes in V2: - Fix a memory leak if the user opens multiple times the trace_stat file without closing it. Now we always free our list before rebuilding it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29 12:44:51 +08:00
return ret;
}
static void *stat_seq_start(struct seq_file *s, loff_t *pos)
{
struct tracer_stat_session *session = s->private;
tracing/ftrace: provide the base infrastructure for histogram tracing Impact: extend the tracing API The goal of this patch is to normalize and make more easy the implementation of statistical (histogram) tracing. It implements a trace_stat file into the /debugfs/tracing directory where one can print a one-shot output of statistics/histogram entries. A tracer has to provide two basic iterator callbacks: stat_start() => the first entry stat_next(prev, idx) => the next one. Note that it is adapted for arrays or hash tables or lists.... since it provides a pointer to the previous entry and the current index of the iterator. These two callbacks are called to get a snapshot of the statistics at each opening of the trace_stat file because. The values are so updated between two "cat trace_stat". And the tracer is free to lock its datas during the iteration to keep consistent values. Since it is almost always interesting to sort statisticals values to address the problems by priority, this infrastructure provides a "sorting" of the stat entries too if desired. A tracer has just to provide a stat_cmp callback to compare two entries and the stat tracing infrastructure will build a sorted list of the given entries. A last callback, called stat_headers, can be implemented by a tracer to output headers on its trace. If one of these callbacks is changed on runtime, it just have to signal it to the stat tracing API by calling the init_tracer_stat() helper. Changes in V2: - Fix a memory leak if the user opens multiple times the trace_stat file without closing it. Now we always free our list before rebuilding it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29 12:44:51 +08:00
/* Prevent from tracer switch or stat_list modification */
mutex_lock(&session->stat_mutex);
tracing/ftrace: provide the base infrastructure for histogram tracing Impact: extend the tracing API The goal of this patch is to normalize and make more easy the implementation of statistical (histogram) tracing. It implements a trace_stat file into the /debugfs/tracing directory where one can print a one-shot output of statistics/histogram entries. A tracer has to provide two basic iterator callbacks: stat_start() => the first entry stat_next(prev, idx) => the next one. Note that it is adapted for arrays or hash tables or lists.... since it provides a pointer to the previous entry and the current index of the iterator. These two callbacks are called to get a snapshot of the statistics at each opening of the trace_stat file because. The values are so updated between two "cat trace_stat". And the tracer is free to lock its datas during the iteration to keep consistent values. Since it is almost always interesting to sort statisticals values to address the problems by priority, this infrastructure provides a "sorting" of the stat entries too if desired. A tracer has just to provide a stat_cmp callback to compare two entries and the stat tracing infrastructure will build a sorted list of the given entries. A last callback, called stat_headers, can be implemented by a tracer to output headers on its trace. If one of these callbacks is changed on runtime, it just have to signal it to the stat tracing API by calling the init_tracer_stat() helper. Changes in V2: - Fix a memory leak if the user opens multiple times the trace_stat file without closing it. Now we always free our list before rebuilding it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29 12:44:51 +08:00
/* If we are in the beginning of the file, print the headers */
if (!*pos && session->ts->stat_headers)
return SEQ_START_TOKEN;
tracing/ftrace: provide the base infrastructure for histogram tracing Impact: extend the tracing API The goal of this patch is to normalize and make more easy the implementation of statistical (histogram) tracing. It implements a trace_stat file into the /debugfs/tracing directory where one can print a one-shot output of statistics/histogram entries. A tracer has to provide two basic iterator callbacks: stat_start() => the first entry stat_next(prev, idx) => the next one. Note that it is adapted for arrays or hash tables or lists.... since it provides a pointer to the previous entry and the current index of the iterator. These two callbacks are called to get a snapshot of the statistics at each opening of the trace_stat file because. The values are so updated between two "cat trace_stat". And the tracer is free to lock its datas during the iteration to keep consistent values. Since it is almost always interesting to sort statisticals values to address the problems by priority, this infrastructure provides a "sorting" of the stat entries too if desired. A tracer has just to provide a stat_cmp callback to compare two entries and the stat tracing infrastructure will build a sorted list of the given entries. A last callback, called stat_headers, can be implemented by a tracer to output headers on its trace. If one of these callbacks is changed on runtime, it just have to signal it to the stat tracing API by calling the init_tracer_stat() helper. Changes in V2: - Fix a memory leak if the user opens multiple times the trace_stat file without closing it. Now we always free our list before rebuilding it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29 12:44:51 +08:00
return seq_list_start(&session->stat_list, *pos);
tracing/ftrace: provide the base infrastructure for histogram tracing Impact: extend the tracing API The goal of this patch is to normalize and make more easy the implementation of statistical (histogram) tracing. It implements a trace_stat file into the /debugfs/tracing directory where one can print a one-shot output of statistics/histogram entries. A tracer has to provide two basic iterator callbacks: stat_start() => the first entry stat_next(prev, idx) => the next one. Note that it is adapted for arrays or hash tables or lists.... since it provides a pointer to the previous entry and the current index of the iterator. These two callbacks are called to get a snapshot of the statistics at each opening of the trace_stat file because. The values are so updated between two "cat trace_stat". And the tracer is free to lock its datas during the iteration to keep consistent values. Since it is almost always interesting to sort statisticals values to address the problems by priority, this infrastructure provides a "sorting" of the stat entries too if desired. A tracer has just to provide a stat_cmp callback to compare two entries and the stat tracing infrastructure will build a sorted list of the given entries. A last callback, called stat_headers, can be implemented by a tracer to output headers on its trace. If one of these callbacks is changed on runtime, it just have to signal it to the stat tracing API by calling the init_tracer_stat() helper. Changes in V2: - Fix a memory leak if the user opens multiple times the trace_stat file without closing it. Now we always free our list before rebuilding it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29 12:44:51 +08:00
}
static void *stat_seq_next(struct seq_file *s, void *p, loff_t *pos)
{
struct tracer_stat_session *session = s->private;
tracing/ftrace: provide the base infrastructure for histogram tracing Impact: extend the tracing API The goal of this patch is to normalize and make more easy the implementation of statistical (histogram) tracing. It implements a trace_stat file into the /debugfs/tracing directory where one can print a one-shot output of statistics/histogram entries. A tracer has to provide two basic iterator callbacks: stat_start() => the first entry stat_next(prev, idx) => the next one. Note that it is adapted for arrays or hash tables or lists.... since it provides a pointer to the previous entry and the current index of the iterator. These two callbacks are called to get a snapshot of the statistics at each opening of the trace_stat file because. The values are so updated between two "cat trace_stat". And the tracer is free to lock its datas during the iteration to keep consistent values. Since it is almost always interesting to sort statisticals values to address the problems by priority, this infrastructure provides a "sorting" of the stat entries too if desired. A tracer has just to provide a stat_cmp callback to compare two entries and the stat tracing infrastructure will build a sorted list of the given entries. A last callback, called stat_headers, can be implemented by a tracer to output headers on its trace. If one of these callbacks is changed on runtime, it just have to signal it to the stat tracing API by calling the init_tracer_stat() helper. Changes in V2: - Fix a memory leak if the user opens multiple times the trace_stat file without closing it. Now we always free our list before rebuilding it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29 12:44:51 +08:00
if (p == SEQ_START_TOKEN)
return seq_list_start(&session->stat_list, *pos);
return seq_list_next(p, &session->stat_list, pos);
tracing/ftrace: provide the base infrastructure for histogram tracing Impact: extend the tracing API The goal of this patch is to normalize and make more easy the implementation of statistical (histogram) tracing. It implements a trace_stat file into the /debugfs/tracing directory where one can print a one-shot output of statistics/histogram entries. A tracer has to provide two basic iterator callbacks: stat_start() => the first entry stat_next(prev, idx) => the next one. Note that it is adapted for arrays or hash tables or lists.... since it provides a pointer to the previous entry and the current index of the iterator. These two callbacks are called to get a snapshot of the statistics at each opening of the trace_stat file because. The values are so updated between two "cat trace_stat". And the tracer is free to lock its datas during the iteration to keep consistent values. Since it is almost always interesting to sort statisticals values to address the problems by priority, this infrastructure provides a "sorting" of the stat entries too if desired. A tracer has just to provide a stat_cmp callback to compare two entries and the stat tracing infrastructure will build a sorted list of the given entries. A last callback, called stat_headers, can be implemented by a tracer to output headers on its trace. If one of these callbacks is changed on runtime, it just have to signal it to the stat tracing API by calling the init_tracer_stat() helper. Changes in V2: - Fix a memory leak if the user opens multiple times the trace_stat file without closing it. Now we always free our list before rebuilding it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29 12:44:51 +08:00
}
static void stat_seq_stop(struct seq_file *s, void *p)
tracing/ftrace: provide the base infrastructure for histogram tracing Impact: extend the tracing API The goal of this patch is to normalize and make more easy the implementation of statistical (histogram) tracing. It implements a trace_stat file into the /debugfs/tracing directory where one can print a one-shot output of statistics/histogram entries. A tracer has to provide two basic iterator callbacks: stat_start() => the first entry stat_next(prev, idx) => the next one. Note that it is adapted for arrays or hash tables or lists.... since it provides a pointer to the previous entry and the current index of the iterator. These two callbacks are called to get a snapshot of the statistics at each opening of the trace_stat file because. The values are so updated between two "cat trace_stat". And the tracer is free to lock its datas during the iteration to keep consistent values. Since it is almost always interesting to sort statisticals values to address the problems by priority, this infrastructure provides a "sorting" of the stat entries too if desired. A tracer has just to provide a stat_cmp callback to compare two entries and the stat tracing infrastructure will build a sorted list of the given entries. A last callback, called stat_headers, can be implemented by a tracer to output headers on its trace. If one of these callbacks is changed on runtime, it just have to signal it to the stat tracing API by calling the init_tracer_stat() helper. Changes in V2: - Fix a memory leak if the user opens multiple times the trace_stat file without closing it. Now we always free our list before rebuilding it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29 12:44:51 +08:00
{
struct tracer_stat_session *session = s->private;
mutex_unlock(&session->stat_mutex);
tracing/ftrace: provide the base infrastructure for histogram tracing Impact: extend the tracing API The goal of this patch is to normalize and make more easy the implementation of statistical (histogram) tracing. It implements a trace_stat file into the /debugfs/tracing directory where one can print a one-shot output of statistics/histogram entries. A tracer has to provide two basic iterator callbacks: stat_start() => the first entry stat_next(prev, idx) => the next one. Note that it is adapted for arrays or hash tables or lists.... since it provides a pointer to the previous entry and the current index of the iterator. These two callbacks are called to get a snapshot of the statistics at each opening of the trace_stat file because. The values are so updated between two "cat trace_stat". And the tracer is free to lock its datas during the iteration to keep consistent values. Since it is almost always interesting to sort statisticals values to address the problems by priority, this infrastructure provides a "sorting" of the stat entries too if desired. A tracer has just to provide a stat_cmp callback to compare two entries and the stat tracing infrastructure will build a sorted list of the given entries. A last callback, called stat_headers, can be implemented by a tracer to output headers on its trace. If one of these callbacks is changed on runtime, it just have to signal it to the stat tracing API by calling the init_tracer_stat() helper. Changes in V2: - Fix a memory leak if the user opens multiple times the trace_stat file without closing it. Now we always free our list before rebuilding it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29 12:44:51 +08:00
}
static int stat_seq_show(struct seq_file *s, void *v)
{
struct tracer_stat_session *session = s->private;
struct trace_stat_list *l = list_entry(v, struct trace_stat_list, list);
if (v == SEQ_START_TOKEN)
return session->ts->stat_headers(s);
return session->ts->stat_show(s, l->stat);
tracing/ftrace: provide the base infrastructure for histogram tracing Impact: extend the tracing API The goal of this patch is to normalize and make more easy the implementation of statistical (histogram) tracing. It implements a trace_stat file into the /debugfs/tracing directory where one can print a one-shot output of statistics/histogram entries. A tracer has to provide two basic iterator callbacks: stat_start() => the first entry stat_next(prev, idx) => the next one. Note that it is adapted for arrays or hash tables or lists.... since it provides a pointer to the previous entry and the current index of the iterator. These two callbacks are called to get a snapshot of the statistics at each opening of the trace_stat file because. The values are so updated between two "cat trace_stat". And the tracer is free to lock its datas during the iteration to keep consistent values. Since it is almost always interesting to sort statisticals values to address the problems by priority, this infrastructure provides a "sorting" of the stat entries too if desired. A tracer has just to provide a stat_cmp callback to compare two entries and the stat tracing infrastructure will build a sorted list of the given entries. A last callback, called stat_headers, can be implemented by a tracer to output headers on its trace. If one of these callbacks is changed on runtime, it just have to signal it to the stat tracing API by calling the init_tracer_stat() helper. Changes in V2: - Fix a memory leak if the user opens multiple times the trace_stat file without closing it. Now we always free our list before rebuilding it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29 12:44:51 +08:00
}
static const struct seq_operations trace_stat_seq_ops = {
.start = stat_seq_start,
.next = stat_seq_next,
.stop = stat_seq_stop,
.show = stat_seq_show
tracing/ftrace: provide the base infrastructure for histogram tracing Impact: extend the tracing API The goal of this patch is to normalize and make more easy the implementation of statistical (histogram) tracing. It implements a trace_stat file into the /debugfs/tracing directory where one can print a one-shot output of statistics/histogram entries. A tracer has to provide two basic iterator callbacks: stat_start() => the first entry stat_next(prev, idx) => the next one. Note that it is adapted for arrays or hash tables or lists.... since it provides a pointer to the previous entry and the current index of the iterator. These two callbacks are called to get a snapshot of the statistics at each opening of the trace_stat file because. The values are so updated between two "cat trace_stat". And the tracer is free to lock its datas during the iteration to keep consistent values. Since it is almost always interesting to sort statisticals values to address the problems by priority, this infrastructure provides a "sorting" of the stat entries too if desired. A tracer has just to provide a stat_cmp callback to compare two entries and the stat tracing infrastructure will build a sorted list of the given entries. A last callback, called stat_headers, can be implemented by a tracer to output headers on its trace. If one of these callbacks is changed on runtime, it just have to signal it to the stat tracing API by calling the init_tracer_stat() helper. Changes in V2: - Fix a memory leak if the user opens multiple times the trace_stat file without closing it. Now we always free our list before rebuilding it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29 12:44:51 +08:00
};
/* The session stat is refilled and resorted at each stat file opening */
tracing/ftrace: provide the base infrastructure for histogram tracing Impact: extend the tracing API The goal of this patch is to normalize and make more easy the implementation of statistical (histogram) tracing. It implements a trace_stat file into the /debugfs/tracing directory where one can print a one-shot output of statistics/histogram entries. A tracer has to provide two basic iterator callbacks: stat_start() => the first entry stat_next(prev, idx) => the next one. Note that it is adapted for arrays or hash tables or lists.... since it provides a pointer to the previous entry and the current index of the iterator. These two callbacks are called to get a snapshot of the statistics at each opening of the trace_stat file because. The values are so updated between two "cat trace_stat". And the tracer is free to lock its datas during the iteration to keep consistent values. Since it is almost always interesting to sort statisticals values to address the problems by priority, this infrastructure provides a "sorting" of the stat entries too if desired. A tracer has just to provide a stat_cmp callback to compare two entries and the stat tracing infrastructure will build a sorted list of the given entries. A last callback, called stat_headers, can be implemented by a tracer to output headers on its trace. If one of these callbacks is changed on runtime, it just have to signal it to the stat tracing API by calling the init_tracer_stat() helper. Changes in V2: - Fix a memory leak if the user opens multiple times the trace_stat file without closing it. Now we always free our list before rebuilding it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29 12:44:51 +08:00
static int tracing_stat_open(struct inode *inode, struct file *file)
{
int ret;
struct tracer_stat_session *session = inode->i_private;
tracing/ftrace: provide the base infrastructure for histogram tracing Impact: extend the tracing API The goal of this patch is to normalize and make more easy the implementation of statistical (histogram) tracing. It implements a trace_stat file into the /debugfs/tracing directory where one can print a one-shot output of statistics/histogram entries. A tracer has to provide two basic iterator callbacks: stat_start() => the first entry stat_next(prev, idx) => the next one. Note that it is adapted for arrays or hash tables or lists.... since it provides a pointer to the previous entry and the current index of the iterator. These two callbacks are called to get a snapshot of the statistics at each opening of the trace_stat file because. The values are so updated between two "cat trace_stat". And the tracer is free to lock its datas during the iteration to keep consistent values. Since it is almost always interesting to sort statisticals values to address the problems by priority, this infrastructure provides a "sorting" of the stat entries too if desired. A tracer has just to provide a stat_cmp callback to compare two entries and the stat tracing infrastructure will build a sorted list of the given entries. A last callback, called stat_headers, can be implemented by a tracer to output headers on its trace. If one of these callbacks is changed on runtime, it just have to signal it to the stat tracing API by calling the init_tracer_stat() helper. Changes in V2: - Fix a memory leak if the user opens multiple times the trace_stat file without closing it. Now we always free our list before rebuilding it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29 12:44:51 +08:00
ret = seq_open(file, &trace_stat_seq_ops);
if (!ret) {
struct seq_file *m = file->private_data;
m->private = session;
ret = stat_seq_init(session);
tracing/ftrace: provide the base infrastructure for histogram tracing Impact: extend the tracing API The goal of this patch is to normalize and make more easy the implementation of statistical (histogram) tracing. It implements a trace_stat file into the /debugfs/tracing directory where one can print a one-shot output of statistics/histogram entries. A tracer has to provide two basic iterator callbacks: stat_start() => the first entry stat_next(prev, idx) => the next one. Note that it is adapted for arrays or hash tables or lists.... since it provides a pointer to the previous entry and the current index of the iterator. These two callbacks are called to get a snapshot of the statistics at each opening of the trace_stat file because. The values are so updated between two "cat trace_stat". And the tracer is free to lock its datas during the iteration to keep consistent values. Since it is almost always interesting to sort statisticals values to address the problems by priority, this infrastructure provides a "sorting" of the stat entries too if desired. A tracer has just to provide a stat_cmp callback to compare two entries and the stat tracing infrastructure will build a sorted list of the given entries. A last callback, called stat_headers, can be implemented by a tracer to output headers on its trace. If one of these callbacks is changed on runtime, it just have to signal it to the stat tracing API by calling the init_tracer_stat() helper. Changes in V2: - Fix a memory leak if the user opens multiple times the trace_stat file without closing it. Now we always free our list before rebuilding it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29 12:44:51 +08:00
}
return ret;
}
/*
* Avoid consuming memory with our now useless list.
*/
static int tracing_stat_release(struct inode *i, struct file *f)
{
struct tracer_stat_session *session = i->i_private;
mutex_lock(&session->stat_mutex);
reset_stat_session(session);
mutex_unlock(&session->stat_mutex);
tracing/ftrace: provide the base infrastructure for histogram tracing Impact: extend the tracing API The goal of this patch is to normalize and make more easy the implementation of statistical (histogram) tracing. It implements a trace_stat file into the /debugfs/tracing directory where one can print a one-shot output of statistics/histogram entries. A tracer has to provide two basic iterator callbacks: stat_start() => the first entry stat_next(prev, idx) => the next one. Note that it is adapted for arrays or hash tables or lists.... since it provides a pointer to the previous entry and the current index of the iterator. These two callbacks are called to get a snapshot of the statistics at each opening of the trace_stat file because. The values are so updated between two "cat trace_stat". And the tracer is free to lock its datas during the iteration to keep consistent values. Since it is almost always interesting to sort statisticals values to address the problems by priority, this infrastructure provides a "sorting" of the stat entries too if desired. A tracer has just to provide a stat_cmp callback to compare two entries and the stat tracing infrastructure will build a sorted list of the given entries. A last callback, called stat_headers, can be implemented by a tracer to output headers on its trace. If one of these callbacks is changed on runtime, it just have to signal it to the stat tracing API by calling the init_tracer_stat() helper. Changes in V2: - Fix a memory leak if the user opens multiple times the trace_stat file without closing it. Now we always free our list before rebuilding it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29 12:44:51 +08:00
return 0;
}
static const struct file_operations tracing_stat_fops = {
.open = tracing_stat_open,
.read = seq_read,
.llseek = seq_lseek,
.release = tracing_stat_release
};
static int tracing_stat_init(void)
tracing/ftrace: provide the base infrastructure for histogram tracing Impact: extend the tracing API The goal of this patch is to normalize and make more easy the implementation of statistical (histogram) tracing. It implements a trace_stat file into the /debugfs/tracing directory where one can print a one-shot output of statistics/histogram entries. A tracer has to provide two basic iterator callbacks: stat_start() => the first entry stat_next(prev, idx) => the next one. Note that it is adapted for arrays or hash tables or lists.... since it provides a pointer to the previous entry and the current index of the iterator. These two callbacks are called to get a snapshot of the statistics at each opening of the trace_stat file because. The values are so updated between two "cat trace_stat". And the tracer is free to lock its datas during the iteration to keep consistent values. Since it is almost always interesting to sort statisticals values to address the problems by priority, this infrastructure provides a "sorting" of the stat entries too if desired. A tracer has just to provide a stat_cmp callback to compare two entries and the stat tracing infrastructure will build a sorted list of the given entries. A last callback, called stat_headers, can be implemented by a tracer to output headers on its trace. If one of these callbacks is changed on runtime, it just have to signal it to the stat tracing API by calling the init_tracer_stat() helper. Changes in V2: - Fix a memory leak if the user opens multiple times the trace_stat file without closing it. Now we always free our list before rebuilding it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29 12:44:51 +08:00
{
struct dentry *d_tracing;
d_tracing = tracing_init_dentry();
stat_dir = debugfs_create_dir("trace_stat", d_tracing);
if (!stat_dir)
tracing/ftrace: provide the base infrastructure for histogram tracing Impact: extend the tracing API The goal of this patch is to normalize and make more easy the implementation of statistical (histogram) tracing. It implements a trace_stat file into the /debugfs/tracing directory where one can print a one-shot output of statistics/histogram entries. A tracer has to provide two basic iterator callbacks: stat_start() => the first entry stat_next(prev, idx) => the next one. Note that it is adapted for arrays or hash tables or lists.... since it provides a pointer to the previous entry and the current index of the iterator. These two callbacks are called to get a snapshot of the statistics at each opening of the trace_stat file because. The values are so updated between two "cat trace_stat". And the tracer is free to lock its datas during the iteration to keep consistent values. Since it is almost always interesting to sort statisticals values to address the problems by priority, this infrastructure provides a "sorting" of the stat entries too if desired. A tracer has just to provide a stat_cmp callback to compare two entries and the stat tracing infrastructure will build a sorted list of the given entries. A last callback, called stat_headers, can be implemented by a tracer to output headers on its trace. If one of these callbacks is changed on runtime, it just have to signal it to the stat tracing API by calling the init_tracer_stat() helper. Changes in V2: - Fix a memory leak if the user opens multiple times the trace_stat file without closing it. Now we always free our list before rebuilding it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-29 12:44:51 +08:00
pr_warning("Could not create debugfs "
"'trace_stat' entry\n");
return 0;
}
static int init_stat_file(struct tracer_stat_session *session)
{
if (!stat_dir && tracing_stat_init())
return -ENODEV;
session->file = debugfs_create_file(session->ts->name, 0644,
stat_dir,
session, &tracing_stat_fops);
if (!session->file)
return -ENOMEM;
return 0;
}
int register_stat_tracer(struct tracer_stat *trace)
{
struct tracer_stat_session *session, *node, *tmp;
int ret;
if (!trace)
return -EINVAL;
if (!trace->stat_start || !trace->stat_next || !trace->stat_show)
return -EINVAL;
/* Already registered? */
mutex_lock(&all_stat_sessions_mutex);
list_for_each_entry_safe(node, tmp, &all_stat_sessions, session_list) {
if (node->ts == trace) {
mutex_unlock(&all_stat_sessions_mutex);
return -EINVAL;
}
}
mutex_unlock(&all_stat_sessions_mutex);
/* Init the session */
session = kmalloc(sizeof(struct tracer_stat_session), GFP_KERNEL);
if (!session)
return -ENOMEM;
session->ts = trace;
INIT_LIST_HEAD(&session->session_list);
INIT_LIST_HEAD(&session->stat_list);
mutex_init(&session->stat_mutex);
session->file = NULL;
ret = init_stat_file(session);
if (ret) {
destroy_session(session);
return ret;
}
/* Register */
mutex_lock(&all_stat_sessions_mutex);
list_add_tail(&session->session_list, &all_stat_sessions);
mutex_unlock(&all_stat_sessions_mutex);
return 0;
}
void unregister_stat_tracer(struct tracer_stat *trace)
{
struct tracer_stat_session *node, *tmp;
mutex_lock(&all_stat_sessions_mutex);
list_for_each_entry_safe(node, tmp, &all_stat_sessions, session_list) {
if (node->ts == trace) {
list_del(&node->session_list);
destroy_session(node);
break;
}
}
mutex_unlock(&all_stat_sessions_mutex);
}