From dbd0b4b33074aa6b7832a9d9a5bd985eca5c1aa2 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Sun, 28 Dec 2008 20:44:51 -0800 Subject: 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 Signed-off-by: Ingo Molnar --- kernel/trace/trace_stat.c | 251 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 251 insertions(+) create mode 100644 kernel/trace/trace_stat.c (limited to 'kernel/trace/trace_stat.c') diff --git a/kernel/trace/trace_stat.c b/kernel/trace/trace_stat.c new file mode 100644 index 00000000000..6f194a33a64 --- /dev/null +++ b/kernel/trace/trace_stat.c @@ -0,0 +1,251 @@ +/* + * Infrastructure for statistic tracing (histogram output). + * + * Copyright (C) 2008 Frederic Weisbecker + * + * Based on the code from trace_branch.c which is + * Copyright (C) 2008 Steven Rostedt + * + */ + + +#include +#include +#include +#include "trace.h" + + +/* List of stat entries from a tracer */ +struct trace_stat_list { + struct list_head list; + void *stat; +}; + +static struct trace_stat_list stat_list; + +/* + * This is a copy of the current tracer to avoid racy + * and dangerous output while the current tracer is + * switched. + */ +static struct tracer current_tracer; + +/* + * Protect both the current tracer and the global + * stat list. + */ +static DEFINE_MUTEX(stat_list_mutex); + + +static void reset_stat_list(void) +{ + struct trace_stat_list *node; + struct list_head *next; + + if (list_empty(&stat_list.list)) + return; + + node = list_entry(stat_list.list.next, struct trace_stat_list, list); + next = node->list.next; + + while (&node->list != next) { + kfree(node); + node = list_entry(next, struct trace_stat_list, list); + } + kfree(node); + + INIT_LIST_HEAD(&stat_list.list); +} + +void init_tracer_stat(struct tracer *trace) +{ + mutex_lock(&stat_list_mutex); + current_tracer = *trace; + mutex_unlock(&stat_list_mutex); +} + +/* + * 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(void) +{ + struct trace_stat_list *iter_entry, *new_entry; + void *prev_stat; + int ret = 0; + int i; + + mutex_lock(&stat_list_mutex); + reset_stat_list(); + + if (!current_tracer.stat_start || !current_tracer.stat_next || + !current_tracer.stat_show) + goto exit; + + if (!current_tracer.stat_cmp) + current_tracer.stat_cmp = dummy_cmp; + + /* + * 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, &stat_list.list); + new_entry->stat = current_tracer.stat_start(); + + prev_stat = new_entry->stat; + + /* + * Iterate over the tracer stat entries and store them in a sorted + * list. + */ + for (i = 1; ; i++) { + 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 = current_tracer.stat_next(prev_stat, i); + + /* End of insertion */ + if (!new_entry->stat) + break; + + list_for_each_entry(iter_entry, &stat_list.list, list) { + /* Insertion with a descendent sorting */ + if (current_tracer.stat_cmp(new_entry->stat, + iter_entry->stat) > 0) { + + list_add_tail(&new_entry->list, + &iter_entry->list); + break; + + /* The current smaller value */ + } else if (list_is_last(&iter_entry->list, + &stat_list.list)) { + list_add(&new_entry->list, &iter_entry->list); + break; + } + } + + prev_stat = new_entry->stat; + } +exit: + mutex_unlock(&stat_list_mutex); + return ret; + +exit_free_list: + reset_stat_list(); + mutex_unlock(&stat_list_mutex); + return ret; +} + + +static void *stat_seq_start(struct seq_file *s, loff_t *pos) +{ + struct trace_stat_list *l = (struct trace_stat_list *)s->private; + + /* Prevent from tracer switch or stat_list modification */ + mutex_lock(&stat_list_mutex); + + /* If we are in the beginning of the file, print the headers */ + if (!*pos && current_tracer.stat_headers) + current_tracer.stat_headers(s); + + return seq_list_start(&l->list, *pos); +} + +static void *stat_seq_next(struct seq_file *s, void *p, loff_t *pos) +{ + struct trace_stat_list *l = (struct trace_stat_list *)s->private; + + return seq_list_next(p, &l->list, pos); +} + +static void stat_seq_stop(struct seq_file *m, void *p) +{ + mutex_unlock(&stat_list_mutex); +} + +static int stat_seq_show(struct seq_file *s, void *v) +{ + struct trace_stat_list *l = list_entry(v, struct trace_stat_list, list); + return current_tracer.stat_show(s, l->stat); +} + +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 +}; + +static int tracing_stat_open(struct inode *inode, struct file *file) +{ + int ret; + + ret = seq_open(file, &trace_stat_seq_ops); + if (!ret) { + struct seq_file *m = file->private_data; + m->private = &stat_list; + ret = stat_seq_init(); + } + + return ret; +} + + +/* + * Avoid consuming memory with our now useless list. + */ +static int tracing_stat_release(struct inode *i, struct file *f) +{ + mutex_lock(&stat_list_mutex); + reset_stat_list(); + mutex_unlock(&stat_list_mutex); + 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 __init tracing_stat_init(void) +{ + struct dentry *d_tracing; + struct dentry *entry; + + INIT_LIST_HEAD(&stat_list.list); + d_tracing = tracing_init_dentry(); + + entry = debugfs_create_file("trace_stat", 0444, d_tracing, + NULL, + &tracing_stat_fops); + if (!entry) + pr_warning("Could not create debugfs " + "'trace_stat' entry\n"); + return 0; +} +fs_initcall(tracing_stat_init); -- cgit v1.2.3-70-g09d2 From ff288b274a9b383046fdbda4be3067daba4d5fe8 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Tue, 6 Jan 2009 21:33:30 +0100 Subject: tracing/ftrace: fix a memory leak in stat tracing Impact: fix memory leak This patch fixes a memory leak inside reset_stat_list(). The freeing loop iterated only once. Also turn the stat_list into a simple struct list_head, which simplify the code and avoid an unused static pointer. Reported-by: Steven Rostedt Signed-off-by: Frederic Weisbecker Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace_stat.c | 39 +++++++++++++++------------------------ 1 file changed, 15 insertions(+), 24 deletions(-) (limited to 'kernel/trace/trace_stat.c') diff --git a/kernel/trace/trace_stat.c b/kernel/trace/trace_stat.c index 6f194a33a64..4cb4ff27646 100644 --- a/kernel/trace/trace_stat.c +++ b/kernel/trace/trace_stat.c @@ -21,7 +21,7 @@ struct trace_stat_list { void *stat; }; -static struct trace_stat_list stat_list; +static LIST_HEAD(stat_list); /* * This is a copy of the current tracer to avoid racy @@ -39,22 +39,12 @@ static DEFINE_MUTEX(stat_list_mutex); static void reset_stat_list(void) { - struct trace_stat_list *node; - struct list_head *next; + struct trace_stat_list *node, *next; - if (list_empty(&stat_list.list)) - return; - - node = list_entry(stat_list.list.next, struct trace_stat_list, list); - next = node->list.next; - - while (&node->list != next) { + list_for_each_entry_safe(node, next, &stat_list, list) kfree(node); - node = list_entry(next, struct trace_stat_list, list); - } - kfree(node); - INIT_LIST_HEAD(&stat_list.list); + INIT_LIST_HEAD(&stat_list); } void init_tracer_stat(struct tracer *trace) @@ -107,7 +97,7 @@ static int stat_seq_init(void) } INIT_LIST_HEAD(&new_entry->list); - list_add(&new_entry->list, &stat_list.list); + list_add(&new_entry->list, &stat_list); new_entry->stat = current_tracer.stat_start(); prev_stat = new_entry->stat; @@ -130,7 +120,7 @@ static int stat_seq_init(void) if (!new_entry->stat) break; - list_for_each_entry(iter_entry, &stat_list.list, list) { + list_for_each_entry(iter_entry, &stat_list, list) { /* Insertion with a descendent sorting */ if (current_tracer.stat_cmp(new_entry->stat, iter_entry->stat) > 0) { @@ -141,7 +131,7 @@ static int stat_seq_init(void) /* The current smaller value */ } else if (list_is_last(&iter_entry->list, - &stat_list.list)) { + &stat_list)) { list_add(&new_entry->list, &iter_entry->list); break; } @@ -162,7 +152,7 @@ exit_free_list: static void *stat_seq_start(struct seq_file *s, loff_t *pos) { - struct trace_stat_list *l = (struct trace_stat_list *)s->private; + struct list_head *l = (struct list_head *)s->private; /* Prevent from tracer switch or stat_list modification */ mutex_lock(&stat_list_mutex); @@ -171,14 +161,14 @@ static void *stat_seq_start(struct seq_file *s, loff_t *pos) if (!*pos && current_tracer.stat_headers) current_tracer.stat_headers(s); - return seq_list_start(&l->list, *pos); + return seq_list_start(l, *pos); } static void *stat_seq_next(struct seq_file *s, void *p, loff_t *pos) { - struct trace_stat_list *l = (struct trace_stat_list *)s->private; + struct list_head *l = (struct list_head *)s->private; - return seq_list_next(p, &l->list, pos); + return seq_list_next(p, l, pos); } static void stat_seq_stop(struct seq_file *m, void *p) @@ -188,8 +178,10 @@ static void stat_seq_stop(struct seq_file *m, void *p) static int stat_seq_show(struct seq_file *s, void *v) { - struct trace_stat_list *l = list_entry(v, struct trace_stat_list, list); - return current_tracer.stat_show(s, l->stat); + struct trace_stat_list *entry = + list_entry(v, struct trace_stat_list, list); + + return current_tracer.stat_show(s, entry->stat); } static const struct seq_operations trace_stat_seq_ops = { @@ -237,7 +229,6 @@ static int __init tracing_stat_init(void) struct dentry *d_tracing; struct dentry *entry; - INIT_LIST_HEAD(&stat_list.list); d_tracing = tracing_init_dentry(); entry = debugfs_create_file("trace_stat", 0444, d_tracing, -- cgit v1.2.3-70-g09d2 From e8a9cbf6ae620d9e5ba9cb42001c033287a284a3 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Tue, 6 Jan 2009 22:02:35 -0500 Subject: trace: clean up funny line breaks in stat_seq_show Impact: clean up Andrew Morton pointed out that the entry assignment in stat_seq_show did not need to be done in the declaration, causing funny line breaks. This patch makes it a bit more pleasing on the eyes. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace_stat.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'kernel/trace/trace_stat.c') diff --git a/kernel/trace/trace_stat.c b/kernel/trace/trace_stat.c index 4cb4ff27646..f110ce9ce7f 100644 --- a/kernel/trace/trace_stat.c +++ b/kernel/trace/trace_stat.c @@ -178,8 +178,9 @@ static void stat_seq_stop(struct seq_file *m, void *p) static int stat_seq_show(struct seq_file *s, void *v) { - struct trace_stat_list *entry = - list_entry(v, struct trace_stat_list, list); + struct trace_stat_list *entry; + + entry = list_entry(v, struct trace_stat_list, list); return current_tracer.stat_show(s, entry->stat); } -- cgit v1.2.3-70-g09d2 From 034939b65ad5ff64b9709210b3469a95153c51a3 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Thu, 8 Jan 2009 10:03:56 -0800 Subject: tracing/ftrace: handle more than one stat file per tracer Impact: new API for tracers Make the stat tracing API reentrant. And also provide the new directory /debugfs/tracing/trace_stat which will contain all the stat files for the current active tracer. Now a tracer will, if desired, want to provide a zero terminated array of tracer_stat structures. Each one contains the callbacks necessary for one stat file. It have to provide at least a name for its stat file, an iterator with stat_start/start_next callback and an output callback for one stat entry. Also adapt the branch tracer to this new API. We create two files "all" and "annotated" inside the /debugfs/tracing/trace_stat directory, making the both stats simultaneously available instead of needing to change an option to switch from one stat file to another. The output of these stats haven't changed. Changes in v2: _ Apply the previous memory leak fix (rebase against tip/master) Changes in v3: _ Merge the patch that adapted the branch tracer to this Api in this patch to not break the kernel build. Signed-off-by: Frederic Weisbecker Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace.h | 35 ++++--- kernel/trace/trace_branch.c | 69 ++++++------- kernel/trace/trace_stat.c | 230 ++++++++++++++++++++++++++++++++------------ 3 files changed, 217 insertions(+), 117 deletions(-) (limited to 'kernel/trace/trace_stat.c') diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 94ed45e93a8..b3f9ad1b4d8 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -334,6 +334,25 @@ struct tracer_flags { /* Makes more easy to define a tracer opt */ #define TRACER_OPT(s, b) .name = #s, .bit = b +/* + * If you want to provide a stat file (one-shot statistics), fill + * an iterator with stat_start/stat_next and a stat_show callbacks. + * The others callbacks are optional. + */ +struct tracer_stat { + /* The name of your stat file */ + const char *name; + /* Iteration over statistic entries */ + void *(*stat_start)(void); + void *(*stat_next)(void *prev, int idx); + /* Compare two entries for sorting (optional) for stats */ + int (*stat_cmp)(void *p1, void *p2); + /* Print a stat entry */ + int (*stat_show)(struct seq_file *s, void *p); + /* Print the headers of your stat entries */ + int (*stat_headers)(struct seq_file *s); +}; + /* * A specific tracer, represented by methods that operate on a trace array: */ @@ -361,21 +380,7 @@ struct tracer { struct tracer *next; int print_max; struct tracer_flags *flags; - - /* - * If you change one of the following on tracing runtime, recall - * init_tracer_stat() - */ - - /* Iteration over statistic entries */ - void *(*stat_start)(void); - void *(*stat_next)(void *prev, int idx); - /* Compare two entries for sorting (optional) for stats */ - int (*stat_cmp)(void *p1, void *p2); - /* Print a stat entry */ - int (*stat_show)(struct seq_file *s, void *p); - /* Print the headers of your stat entries */ - int (*stat_headers)(struct seq_file *s); + struct tracer_stat *stats; }; struct trace_seq { diff --git a/kernel/trace/trace_branch.c b/kernel/trace/trace_branch.c index 4785a3b9bc4..da5cf3e5581 100644 --- a/kernel/trace/trace_branch.c +++ b/kernel/trace/trace_branch.c @@ -306,19 +306,6 @@ static int annotated_branch_stat_cmp(void *p1, void *p2) } #ifdef CONFIG_PROFILE_ALL_BRANCHES -enum { - TRACE_BRANCH_OPT_ALL = 0x1 -}; - -static struct tracer_opt branch_opts[] = { - { TRACER_OPT(stat_all_branch, TRACE_BRANCH_OPT_ALL) }, - { } -}; - -static struct tracer_flags branch_flags = { - .val = 0, - .opts = branch_opts -}; extern unsigned long __start_branch_profile[]; extern unsigned long __stop_branch_profile[]; @@ -352,28 +339,36 @@ all_branch_stat_next(void *v, int idx) return p; } -static int branch_set_flag(u32 old_flags, u32 bit, int set) -{ - if (bit == TRACE_BRANCH_OPT_ALL) { - if (set) { - branch_trace.stat_headers = all_branch_stat_headers; - branch_trace.stat_start = all_branch_stat_start; - branch_trace.stat_next = all_branch_stat_next; - branch_trace.stat_cmp = NULL; - } else { - branch_trace.stat_headers = - annotated_branch_stat_headers; - branch_trace.stat_start = annotated_branch_stat_start; - branch_trace.stat_next = annotated_branch_stat_next; - branch_trace.stat_cmp = annotated_branch_stat_cmp; - } - init_tracer_stat(&branch_trace); - } - return 0; -} +static struct tracer_stat branch_stats[] = { + {.name = "annotated", + .stat_start = annotated_branch_stat_start, + .stat_next = annotated_branch_stat_next, + .stat_cmp = annotated_branch_stat_cmp, + .stat_headers = annotated_branch_stat_headers, + .stat_show = branch_stat_show}, + {.name = "all", + .stat_start = all_branch_stat_start, + .stat_next = all_branch_stat_next, + .stat_headers = all_branch_stat_headers, + .stat_show = branch_stat_show}, + + { } +}; +#else +static struct tracer_stat branch_stats[] = { + {.name = "annotated", + .stat_start = annotated_branch_stat_start, + .stat_next = annotated_branch_stat_next, + .stat_cmp = annotated_branch_stat_cmp, + .stat_headers = annotated_branch_stat_headers, + .stat_show = branch_stat_show}, + + { } +}; #endif /* CONFIG_PROFILE_ALL_BRANCHES */ + static struct tracer branch_trace __read_mostly = { .name = "branch", @@ -383,16 +378,8 @@ static struct tracer branch_trace __read_mostly = #ifdef CONFIG_FTRACE_SELFTEST .selftest = trace_selftest_startup_branch, #endif /* CONFIG_FTRACE_SELFTEST */ -#endif /* CONFIG_BRANCH_TRACER */ - .stat_start = annotated_branch_stat_start, - .stat_next = annotated_branch_stat_next, - .stat_show = branch_stat_show, - .stat_headers = annotated_branch_stat_headers, - .stat_cmp = annotated_branch_stat_cmp, -#ifdef CONFIG_PROFILE_ALL_BRANCHES - .flags = &branch_flags, - .set_flag = branch_set_flag, #endif + .stats = branch_stats }; __init static int init_branch_trace(void) diff --git a/kernel/trace/trace_stat.c b/kernel/trace/trace_stat.c index f110ce9ce7f..1515f9e7adf 100644 --- a/kernel/trace/trace_stat.c +++ b/kernel/trace/trace_stat.c @@ -21,37 +21,87 @@ struct trace_stat_list { void *stat; }; -static LIST_HEAD(stat_list); - -/* - * This is a copy of the current tracer to avoid racy - * and dangerous output while the current tracer is - * switched. - */ -static struct tracer current_tracer; +/* A stat session is the stats output in one file */ +struct tracer_stat_session { + struct tracer_stat *ts; + struct list_head stat_list; + struct mutex stat_mutex; +}; -/* - * Protect both the current tracer and the global - * stat list. - */ -static DEFINE_MUTEX(stat_list_mutex); +/* All of the sessions currently in use. Each stat file embeed one session */ +static struct tracer_stat_session **all_stat_sessions; +static int nb_sessions; +static struct dentry *stat_dir, **stat_files; -static void reset_stat_list(void) +static void reset_stat_session(struct tracer_stat_session *session) { struct trace_stat_list *node, *next; - list_for_each_entry_safe(node, next, &stat_list, list) + list_for_each_entry_safe(node, next, &session->stat_list, list) kfree(node); - INIT_LIST_HEAD(&stat_list); + INIT_LIST_HEAD(&session->stat_list); } -void init_tracer_stat(struct tracer *trace) +/* Called when a tracer is initialized */ +static int init_all_sessions(int nb, struct tracer_stat *ts) { - mutex_lock(&stat_list_mutex); - current_tracer = *trace; - mutex_unlock(&stat_list_mutex); + int i, j; + struct tracer_stat_session *session; + + nb_sessions = 0; + + if (all_stat_sessions) { + for (i = 0; i < nb_sessions; i++) { + session = all_stat_sessions[i]; + reset_stat_session(session); + mutex_destroy(&session->stat_mutex); + kfree(session); + } + } + all_stat_sessions = kmalloc(sizeof(struct tracer_stat_session *) * nb, + GFP_KERNEL); + if (!all_stat_sessions) + return -ENOMEM; + + for (i = 0; i < nb; i++) { + session = kmalloc(sizeof(struct tracer_stat_session) * nb, + GFP_KERNEL); + if (!session) + goto free_sessions; + + INIT_LIST_HEAD(&session->stat_list); + mutex_init(&session->stat_mutex); + session->ts = &ts[i]; + all_stat_sessions[i] = session; + } + nb_sessions = nb; + return 0; + +free_sessions: + + for (j = 0; j < i; j++) + kfree(all_stat_sessions[i]); + + kfree(all_stat_sessions); + all_stat_sessions = NULL; + + return -ENOMEM; +} + +static int basic_tracer_stat_checks(struct tracer_stat *ts) +{ + int i; + + if (!ts) + return 0; + + for (i = 0; ts[i].name; i++) { + if (!ts[i].stat_start || !ts[i].stat_next || !ts[i].stat_show) + return -EBUSY; + } + return i; } /* @@ -69,22 +119,19 @@ static int dummy_cmp(void *p1, void *p2) * 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(void) +static int stat_seq_init(struct tracer_stat_session *session) { struct trace_stat_list *iter_entry, *new_entry; + struct tracer_stat *ts = session->ts; void *prev_stat; int ret = 0; int i; - mutex_lock(&stat_list_mutex); - reset_stat_list(); - - if (!current_tracer.stat_start || !current_tracer.stat_next || - !current_tracer.stat_show) - goto exit; + mutex_lock(&session->stat_mutex); + reset_stat_session(session); - if (!current_tracer.stat_cmp) - current_tracer.stat_cmp = dummy_cmp; + if (!ts->stat_cmp) + ts->stat_cmp = dummy_cmp; /* * The first entry. Actually this is the second, but the first @@ -97,9 +144,10 @@ static int stat_seq_init(void) } INIT_LIST_HEAD(&new_entry->list); - list_add(&new_entry->list, &stat_list); - new_entry->stat = current_tracer.stat_start(); + list_add(&new_entry->list, &session->stat_list); + + new_entry->stat = ts->stat_start(); prev_stat = new_entry->stat; /* @@ -114,15 +162,16 @@ static int stat_seq_init(void) } INIT_LIST_HEAD(&new_entry->list); - new_entry->stat = current_tracer.stat_next(prev_stat, i); + new_entry->stat = ts->stat_next(prev_stat, i); /* End of insertion */ if (!new_entry->stat) break; - list_for_each_entry(iter_entry, &stat_list, list) { + list_for_each_entry(iter_entry, &session->stat_list, list) { + /* Insertion with a descendent sorting */ - if (current_tracer.stat_cmp(new_entry->stat, + if (ts->stat_cmp(new_entry->stat, iter_entry->stat) > 0) { list_add_tail(&new_entry->list, @@ -131,7 +180,7 @@ static int stat_seq_init(void) /* The current smaller value */ } else if (list_is_last(&iter_entry->list, - &stat_list)) { + &session->stat_list)) { list_add(&new_entry->list, &iter_entry->list); break; } @@ -140,49 +189,49 @@ static int stat_seq_init(void) prev_stat = new_entry->stat; } exit: - mutex_unlock(&stat_list_mutex); + mutex_unlock(&session->stat_mutex); return ret; exit_free_list: - reset_stat_list(); - mutex_unlock(&stat_list_mutex); + reset_stat_session(session); + mutex_unlock(&session->stat_mutex); return ret; } static void *stat_seq_start(struct seq_file *s, loff_t *pos) { - struct list_head *l = (struct list_head *)s->private; + struct tracer_stat_session *session = s->private; /* Prevent from tracer switch or stat_list modification */ - mutex_lock(&stat_list_mutex); + mutex_lock(&session->stat_mutex); /* If we are in the beginning of the file, print the headers */ - if (!*pos && current_tracer.stat_headers) - current_tracer.stat_headers(s); + if (!*pos && session->ts->stat_headers) + session->ts->stat_headers(s); - return seq_list_start(l, *pos); + return seq_list_start(&session->stat_list, *pos); } static void *stat_seq_next(struct seq_file *s, void *p, loff_t *pos) { - struct list_head *l = (struct list_head *)s->private; + struct tracer_stat_session *session = s->private; - return seq_list_next(p, l, pos); + return seq_list_next(p, &session->stat_list, pos); } -static void stat_seq_stop(struct seq_file *m, void *p) +static void stat_seq_stop(struct seq_file *s, void *p) { - mutex_unlock(&stat_list_mutex); + struct tracer_stat_session *session = s->private; + mutex_unlock(&session->stat_mutex); } static int stat_seq_show(struct seq_file *s, void *v) { - struct trace_stat_list *entry; - - entry = list_entry(v, struct trace_stat_list, list); + struct tracer_stat_session *session = s->private; + struct trace_stat_list *l = list_entry(v, struct trace_stat_list, list); - return current_tracer.stat_show(s, entry->stat); + return session->ts->stat_show(s, l->stat); } static const struct seq_operations trace_stat_seq_ops = { @@ -192,15 +241,18 @@ static const struct seq_operations trace_stat_seq_ops = { .show = stat_seq_show }; +/* The session stat is refilled and resorted at each stat file opening */ static int tracing_stat_open(struct inode *inode, struct file *file) { int ret; + struct tracer_stat_session *session = inode->i_private; + ret = seq_open(file, &trace_stat_seq_ops); if (!ret) { struct seq_file *m = file->private_data; - m->private = &stat_list; - ret = stat_seq_init(); + m->private = session; + ret = stat_seq_init(session); } return ret; @@ -212,9 +264,12 @@ static int tracing_stat_open(struct inode *inode, struct file *file) */ static int tracing_stat_release(struct inode *i, struct file *f) { - mutex_lock(&stat_list_mutex); - reset_stat_list(); - mutex_unlock(&stat_list_mutex); + struct tracer_stat_session *session = i->i_private; + + mutex_lock(&session->stat_mutex); + reset_stat_session(session); + mutex_unlock(&session->stat_mutex); + return 0; } @@ -225,17 +280,70 @@ static const struct file_operations tracing_stat_fops = { .release = tracing_stat_release }; + +static void destroy_trace_stat_files(void) +{ + int i; + + if (stat_files) { + for (i = 0; i < nb_sessions; i++) + debugfs_remove(stat_files[i]); + kfree(stat_files); + stat_files = NULL; + } +} + +static void init_trace_stat_files(void) +{ + int i; + + if (!stat_dir || !nb_sessions) + return; + + stat_files = kmalloc(sizeof(struct dentry *) * nb_sessions, GFP_KERNEL); + + if (!stat_files) { + pr_warning("trace stat: not enough memory\n"); + return; + } + + for (i = 0; i < nb_sessions; i++) { + struct tracer_stat_session *session = all_stat_sessions[i]; + stat_files[i] = debugfs_create_file(session->ts->name, 0644, + stat_dir, + session, &tracing_stat_fops); + if (!stat_files[i]) + pr_warning("cannot create %s entry\n", + session->ts->name); + } +} + +void init_tracer_stat(struct tracer *trace) +{ + int nb = basic_tracer_stat_checks(trace->stats); + + destroy_trace_stat_files(); + + if (nb < 0) { + pr_warning("stat tracing: missing stat callback on %s\n", + trace->name); + return; + } + if (!nb) + return; + + init_all_sessions(nb, trace->stats); + init_trace_stat_files(); +} + static int __init tracing_stat_init(void) { struct dentry *d_tracing; - struct dentry *entry; d_tracing = tracing_init_dentry(); - entry = debugfs_create_file("trace_stat", 0444, d_tracing, - NULL, - &tracing_stat_fops); - if (!entry) + stat_dir = debugfs_create_dir("trace_stat", d_tracing); + if (!stat_dir) pr_warning("Could not create debugfs " "'trace_stat' entry\n"); return 0; -- cgit v1.2.3-70-g09d2 From 002bb86d8d42f18937aef396c3ecd65c7e02e21a Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Sat, 10 Jan 2009 11:34:13 -0800 Subject: tracing/ftrace: separate events tracing and stats tracing engine Impact: tracing's Api change Currently, the stat tracing depends on the events tracing. When you switch to a new tracer, the stats files of the previous tracer will disappear. But it's more scalable to separate those two engines. This way, we can keep the stat files of one or several tracers when we want, without bothering of multiple tracer stat files or tracer switching. To build/destroys its stats files, a tracer just have to call register_stat_tracer/unregister_stat_tracer everytimes it wants to. Signed-off-by: Frederic Weisbecker Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 2 - kernel/trace/trace.h | 20 ----- kernel/trace/trace_branch.c | 108 ++++++++++++++----------- kernel/trace/trace_stat.c | 191 +++++++++++++++++++------------------------- kernel/trace/trace_stat.h | 31 +++++++ 5 files changed, 172 insertions(+), 180 deletions(-) create mode 100644 kernel/trace/trace_stat.h (limited to 'kernel/trace/trace_stat.c') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 0418fc338b5..40217fb499e 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2353,7 +2353,6 @@ static int tracing_set_tracer(char *buf) if (ret) goto out; } - init_tracer_stat(t); trace_branch_enable(tr); out: @@ -3218,7 +3217,6 @@ __init static int tracer_alloc_buffers(void) #else current_trace = &nop_trace; #endif - init_tracer_stat(current_trace); /* All seems OK, enable tracing */ tracing_disabled = 0; diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index b3f9ad1b4d8..79c872100dd 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -334,24 +334,6 @@ struct tracer_flags { /* Makes more easy to define a tracer opt */ #define TRACER_OPT(s, b) .name = #s, .bit = b -/* - * If you want to provide a stat file (one-shot statistics), fill - * an iterator with stat_start/stat_next and a stat_show callbacks. - * The others callbacks are optional. - */ -struct tracer_stat { - /* The name of your stat file */ - const char *name; - /* Iteration over statistic entries */ - void *(*stat_start)(void); - void *(*stat_next)(void *prev, int idx); - /* Compare two entries for sorting (optional) for stats */ - int (*stat_cmp)(void *p1, void *p2); - /* Print a stat entry */ - int (*stat_show)(struct seq_file *s, void *p); - /* Print the headers of your stat entries */ - int (*stat_headers)(struct seq_file *s); -}; /* * A specific tracer, represented by methods that operate on a trace array: @@ -466,8 +448,6 @@ void tracing_start_sched_switch_record(void); int register_tracer(struct tracer *type); void unregister_tracer(struct tracer *type); -void init_tracer_stat(struct tracer *trace); - extern unsigned long nsecs_to_usecs(unsigned long nsecs); extern unsigned long tracing_max_latency; diff --git a/kernel/trace/trace_branch.c b/kernel/trace/trace_branch.c index da5cf3e5581..ca017e0a9a2 100644 --- a/kernel/trace/trace_branch.c +++ b/kernel/trace/trace_branch.c @@ -16,12 +16,12 @@ #include #include "trace.h" +#include "trace_stat.h" #include "trace_output.h" -static struct tracer branch_trace; - #ifdef CONFIG_BRANCH_TRACER +static struct tracer branch_trace; static int branch_tracing_enabled __read_mostly; static DEFINE_MUTEX(branch_tracing_mutex); @@ -191,6 +191,30 @@ static struct trace_event trace_branch_event = { .binary = trace_nop_print, }; +static struct tracer branch_trace __read_mostly = +{ + .name = "branch", + .init = branch_trace_init, + .reset = branch_trace_reset, +#ifdef CONFIG_FTRACE_SELFTEST + .selftest = trace_selftest_startup_branch, +#endif /* CONFIG_FTRACE_SELFTEST */ +}; + +__init static int init_branch_tracer(void) +{ + int ret; + + ret = register_ftrace_event(&trace_branch_event); + if (!ret) { + printk(KERN_WARNING "Warning: could not register " + "branch events\n"); + return 1; + } + return register_tracer(&branch_trace); +} +device_initcall(init_branch_tracer); + #else static inline void trace_likely_condition(struct ftrace_branch_data *f, int val, int expect) @@ -305,6 +329,29 @@ static int annotated_branch_stat_cmp(void *p1, void *p2) return 0; } +static struct tracer_stat annotated_branch_stats = { + .name = "branch_annotated", + .stat_start = annotated_branch_stat_start, + .stat_next = annotated_branch_stat_next, + .stat_cmp = annotated_branch_stat_cmp, + .stat_headers = annotated_branch_stat_headers, + .stat_show = branch_stat_show +}; + +__init static int init_annotated_branch_stats(void) +{ + int ret; + + ret = register_stat_tracer(&annotated_branch_stats); + if (!ret) { + printk(KERN_WARNING "Warning: could not register " + "annotated branches stats\n"); + return 1; + } + return 0; +} +fs_initcall(init_annotated_branch_stats); + #ifdef CONFIG_PROFILE_ALL_BRANCHES extern unsigned long __start_branch_profile[]; @@ -339,60 +386,25 @@ all_branch_stat_next(void *v, int idx) return p; } -static struct tracer_stat branch_stats[] = { - {.name = "annotated", - .stat_start = annotated_branch_stat_start, - .stat_next = annotated_branch_stat_next, - .stat_cmp = annotated_branch_stat_cmp, - .stat_headers = annotated_branch_stat_headers, - .stat_show = branch_stat_show}, - - {.name = "all", +static struct tracer_stat all_branch_stats = { + .name = "branch_all", .stat_start = all_branch_stat_start, .stat_next = all_branch_stat_next, .stat_headers = all_branch_stat_headers, - .stat_show = branch_stat_show}, - - { } -}; -#else -static struct tracer_stat branch_stats[] = { - {.name = "annotated", - .stat_start = annotated_branch_stat_start, - .stat_next = annotated_branch_stat_next, - .stat_cmp = annotated_branch_stat_cmp, - .stat_headers = annotated_branch_stat_headers, - .stat_show = branch_stat_show}, - - { } + .stat_show = branch_stat_show }; -#endif /* CONFIG_PROFILE_ALL_BRANCHES */ - -static struct tracer branch_trace __read_mostly = +__init static int all_annotated_branch_stats(void) { - .name = "branch", -#ifdef CONFIG_BRANCH_TRACER - .init = branch_trace_init, - .reset = branch_trace_reset, -#ifdef CONFIG_FTRACE_SELFTEST - .selftest = trace_selftest_startup_branch, -#endif /* CONFIG_FTRACE_SELFTEST */ -#endif - .stats = branch_stats -}; - -__init static int init_branch_trace(void) -{ -#ifdef CONFIG_BRANCH_TRACER int ret; - ret = register_ftrace_event(&trace_branch_event); + + ret = register_stat_tracer(&all_branch_stats); if (!ret) { - printk(KERN_WARNING "Warning: could not register branch events\n"); + printk(KERN_WARNING "Warning: could not register " + "all branches stats\n"); return 1; } -#endif - - return register_tracer(&branch_trace); + return 0; } -device_initcall(init_branch_trace); +fs_initcall(all_annotated_branch_stats); +#endif /* CONFIG_PROFILE_ALL_BRANCHES */ diff --git a/kernel/trace/trace_stat.c b/kernel/trace/trace_stat.c index 1515f9e7adf..cb29282b948 100644 --- a/kernel/trace/trace_stat.c +++ b/kernel/trace/trace_stat.c @@ -10,28 +10,32 @@ #include -#include #include +#include "trace_stat.h" #include "trace.h" /* List of stat entries from a tracer */ struct trace_stat_list { - struct list_head list; - void *stat; + struct list_head list; + void *stat; }; /* A stat session is the stats output in one file */ struct tracer_stat_session { - struct tracer_stat *ts; - struct list_head stat_list; - struct mutex stat_mutex; + struct list_head session_list; + struct tracer_stat *ts; + struct list_head stat_list; + struct mutex stat_mutex; + struct dentry *file; }; /* All of the sessions currently in use. Each stat file embeed one session */ -static struct tracer_stat_session **all_stat_sessions; -static int nb_sessions; -static struct dentry *stat_dir, **stat_files; +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; static void reset_stat_session(struct tracer_stat_session *session) @@ -44,66 +48,77 @@ static void reset_stat_session(struct tracer_stat_session *session) INIT_LIST_HEAD(&session->stat_list); } -/* Called when a tracer is initialized */ -static int init_all_sessions(int nb, struct tracer_stat *ts) +static void destroy_session(struct tracer_stat_session *session) { - int i, j; - struct tracer_stat_session *session; + debugfs_remove(session->file); + reset_stat_session(session); + mutex_destroy(&session->stat_mutex); + kfree(session); +} - nb_sessions = 0; - if (all_stat_sessions) { - for (i = 0; i < nb_sessions; i++) { - session = all_stat_sessions[i]; - reset_stat_session(session); - mutex_destroy(&session->stat_mutex); - kfree(session); - } - } - all_stat_sessions = kmalloc(sizeof(struct tracer_stat_session *) * nb, - GFP_KERNEL); - if (!all_stat_sessions) - return -ENOMEM; +static int init_stat_file(struct tracer_stat_session *session); - for (i = 0; i < nb; i++) { - session = kmalloc(sizeof(struct tracer_stat_session) * nb, - GFP_KERNEL); - if (!session) - goto free_sessions; +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; - INIT_LIST_HEAD(&session->stat_list); - mutex_init(&session->stat_mutex); - session->ts = &ts[i]; - all_stat_sessions[i] = session; + /* Already registered? */ + mutex_lock(&all_stat_sessions_mutex); + list_for_each_entry_safe(node, tmp, &all_stat_sessions, session_list) { + if (node->ts == trace) + return -EINVAL; } - nb_sessions = nb; - return 0; + mutex_unlock(&all_stat_sessions_mutex); + + /* Init the session */ + session = kmalloc(sizeof(struct tracer_stat_session), GFP_KERNEL); + if (!session) + return -ENOMEM; -free_sessions: + session->ts = trace; + INIT_LIST_HEAD(&session->session_list); + INIT_LIST_HEAD(&session->stat_list); + mutex_init(&session->stat_mutex); + session->file = NULL; - for (j = 0; j < i; j++) - kfree(all_stat_sessions[i]); + ret = init_stat_file(session); + if (ret) { + destroy_session(session); + return ret; + } - kfree(all_stat_sessions); - all_stat_sessions = NULL; + /* Register */ + mutex_lock(&all_stat_sessions_mutex); + list_add_tail(&session->session_list, &all_stat_sessions); + mutex_unlock(&all_stat_sessions_mutex); - return -ENOMEM; + return 0; } -static int basic_tracer_stat_checks(struct tracer_stat *ts) +void unregister_stat_tracer(struct tracer_stat *trace) { - int i; + struct tracer_stat_session *node, *tmp; - if (!ts) - return 0; - - for (i = 0; ts[i].name; i++) { - if (!ts[i].stat_start || !ts[i].stat_next || !ts[i].stat_show) - return -EBUSY; + 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; + } } - return i; + mutex_unlock(&all_stat_sessions_mutex); } + /* * For tracers that don't provide a stat_cmp callback. * This one will force an immediate insertion on tail of @@ -280,63 +295,7 @@ static const struct file_operations tracing_stat_fops = { .release = tracing_stat_release }; - -static void destroy_trace_stat_files(void) -{ - int i; - - if (stat_files) { - for (i = 0; i < nb_sessions; i++) - debugfs_remove(stat_files[i]); - kfree(stat_files); - stat_files = NULL; - } -} - -static void init_trace_stat_files(void) -{ - int i; - - if (!stat_dir || !nb_sessions) - return; - - stat_files = kmalloc(sizeof(struct dentry *) * nb_sessions, GFP_KERNEL); - - if (!stat_files) { - pr_warning("trace stat: not enough memory\n"); - return; - } - - for (i = 0; i < nb_sessions; i++) { - struct tracer_stat_session *session = all_stat_sessions[i]; - stat_files[i] = debugfs_create_file(session->ts->name, 0644, - stat_dir, - session, &tracing_stat_fops); - if (!stat_files[i]) - pr_warning("cannot create %s entry\n", - session->ts->name); - } -} - -void init_tracer_stat(struct tracer *trace) -{ - int nb = basic_tracer_stat_checks(trace->stats); - - destroy_trace_stat_files(); - - if (nb < 0) { - pr_warning("stat tracing: missing stat callback on %s\n", - trace->name); - return; - } - if (!nb) - return; - - init_all_sessions(nb, trace->stats); - init_trace_stat_files(); -} - -static int __init tracing_stat_init(void) +static int tracing_stat_init(void) { struct dentry *d_tracing; @@ -348,4 +307,16 @@ static int __init tracing_stat_init(void) "'trace_stat' entry\n"); return 0; } -fs_initcall(tracing_stat_init); + +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; +} diff --git a/kernel/trace/trace_stat.h b/kernel/trace/trace_stat.h new file mode 100644 index 00000000000..202274cf7f3 --- /dev/null +++ b/kernel/trace/trace_stat.h @@ -0,0 +1,31 @@ +#ifndef __TRACE_STAT_H +#define __TRACE_STAT_H + +#include + +/* + * If you want to provide a stat file (one-shot statistics), fill + * an iterator with stat_start/stat_next and a stat_show callbacks. + * The others callbacks are optional. + */ +struct tracer_stat { + /* The name of your stat file */ + const char *name; + /* Iteration over statistic entries */ + void *(*stat_start)(void); + void *(*stat_next)(void *prev, int idx); + /* Compare two entries for stats sorting */ + int (*stat_cmp)(void *p1, void *p2); + /* Print a stat entry */ + int (*stat_show)(struct seq_file *s, void *p); + /* Print the headers of your stat entries */ + int (*stat_headers)(struct seq_file *s); +}; + +/* + * Destroy or create a stat file + */ +extern int register_stat_tracer(struct tracer_stat *trace); +extern void unregister_stat_tracer(struct tracer_stat *trace); + +#endif /* __TRACE_STAT_H */ -- cgit v1.2.3-70-g09d2 From 42fab4b2cdc02cf28e2474ccfd75bc9225076590 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Thu, 15 Jan 2009 09:30:52 +0800 Subject: tracing/ftrace: add missing unlock in register_stat_tracer() We should unlock all_stat_sessions_mutex before returning failure. Signed-off-by: Li Zefan Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace_stat.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'kernel/trace/trace_stat.c') diff --git a/kernel/trace/trace_stat.c b/kernel/trace/trace_stat.c index cb29282b948..2110cea2ece 100644 --- a/kernel/trace/trace_stat.c +++ b/kernel/trace/trace_stat.c @@ -73,8 +73,10 @@ int register_stat_tracer(struct tracer_stat *trace) /* Already registered? */ mutex_lock(&all_stat_sessions_mutex); list_for_each_entry_safe(node, tmp, &all_stat_sessions, session_list) { - if (node->ts == trace) + if (node->ts == trace) { + mutex_unlock(&all_stat_sessions_mutex); return -EINVAL; + } } mutex_unlock(&all_stat_sessions_mutex); -- cgit v1.2.3-70-g09d2 From 55922173f1f63903b6de03711ab8ff980cbe58d2 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Thu, 15 Jan 2009 11:31:21 +0100 Subject: tracing: trace_stat.c cleanup Impact: cleanup - whitespace / code alignment cleanups - avoid unnecessary forward prototype by reordering functions Signed-off-by: Ingo Molnar --- kernel/trace/trace_stat.c | 147 ++++++++++++++++++++++------------------------ 1 file changed, 71 insertions(+), 76 deletions(-) (limited to 'kernel/trace/trace_stat.c') diff --git a/kernel/trace/trace_stat.c b/kernel/trace/trace_stat.c index 2110cea2ece..eae9cef3929 100644 --- a/kernel/trace/trace_stat.c +++ b/kernel/trace/trace_stat.c @@ -17,16 +17,16 @@ /* List of stat entries from a tracer */ struct trace_stat_list { - struct list_head list; - void *stat; + struct list_head list; + void *stat; }; /* 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 tracer_stat *ts; + struct list_head stat_list; + struct mutex stat_mutex; struct dentry *file; }; @@ -35,7 +35,7 @@ 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; +static struct dentry *stat_dir; static void reset_stat_session(struct tracer_stat_session *session) @@ -56,71 +56,6 @@ static void destroy_session(struct tracer_stat_session *session) kfree(session); } - -static int init_stat_file(struct tracer_stat_session *session); - -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); -} - - /* * For tracers that don't provide a stat_cmp callback. * This one will force an immediate insertion on tail of @@ -252,10 +187,10 @@ static int stat_seq_show(struct seq_file *s, void *v) } 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 + .start = stat_seq_start, + .next = stat_seq_next, + .stop = stat_seq_stop, + .show = stat_seq_show }; /* The session stat is refilled and resorted at each stat file opening */ @@ -275,7 +210,6 @@ static int tracing_stat_open(struct inode *inode, struct file *file) return ret; } - /* * Avoid consuming memory with our now useless list. */ @@ -322,3 +256,64 @@ static int init_stat_file(struct tracer_stat_session *session) 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); +} -- cgit v1.2.3-70-g09d2 From 73d8b8bc4f24a97a406d09c8268ac019f4ac661e Mon Sep 17 00:00:00 2001 From: Wenji Huang Date: Tue, 17 Feb 2009 01:10:02 -0500 Subject: tracing: fix typing mistake in hint message and comments Impact: cleanup Fix incorrect hint message in code and typos in comments. Signed-off-by: Wenji Huang Signed-off-by: Steven Rostedt --- kernel/trace/trace_irqsoff.c | 2 +- kernel/trace/trace_sched_switch.c | 2 +- kernel/trace/trace_sched_wakeup.c | 2 +- kernel/trace/trace_selftest.c | 4 ++-- kernel/trace/trace_stat.c | 2 +- kernel/trace/trace_sysprof.c | 2 +- 6 files changed, 7 insertions(+), 7 deletions(-) (limited to 'kernel/trace/trace_stat.c') diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c index c6b442d88de..9e5ebd84415 100644 --- a/kernel/trace/trace_irqsoff.c +++ b/kernel/trace/trace_irqsoff.c @@ -1,5 +1,5 @@ /* - * trace irqs off criticall timings + * trace irqs off critical timings * * Copyright (C) 2007-2008 Steven Rostedt * Copyright (C) 2008 Ingo Molnar diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c index 30e14fe8589..82fbb5a2df8 100644 --- a/kernel/trace/trace_sched_switch.c +++ b/kernel/trace/trace_sched_switch.c @@ -93,7 +93,7 @@ static int tracing_sched_register(void) ret = register_trace_sched_switch(probe_sched_switch); if (ret) { pr_info("sched trace: Couldn't activate tracepoint" - " probe to kernel_sched_schedule\n"); + " probe to kernel_sched_switch\n"); goto fail_deprobe_wake_new; } diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c index 96d71648589..276c51aaf31 100644 --- a/kernel/trace/trace_sched_wakeup.c +++ b/kernel/trace/trace_sched_wakeup.c @@ -284,7 +284,7 @@ static void start_wakeup_tracer(struct trace_array *tr) ret = register_trace_sched_switch(probe_wakeup_sched_switch); if (ret) { pr_info("sched trace: Couldn't activate tracepoint" - " probe to kernel_sched_schedule\n"); + " probe to kernel_sched_switch\n"); goto fail_deprobe_wake_new; } diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index c72e749bcbe..01415f4edaa 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -107,9 +107,9 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace, func(); /* - * Some archs *cough*PowerPC*cough* add charachters to the + * Some archs *cough*PowerPC*cough* add characters to the * start of the function names. We simply put a '*' to - * accomodate them. + * accommodate them. */ func_name = "*" STR(DYN_FTRACE_TEST_NAME); diff --git a/kernel/trace/trace_stat.c b/kernel/trace/trace_stat.c index eae9cef3929..39310e3434e 100644 --- a/kernel/trace/trace_stat.c +++ b/kernel/trace/trace_stat.c @@ -30,7 +30,7 @@ struct tracer_stat_session { struct dentry *file; }; -/* All of the sessions currently in use. Each stat file embeed one session */ +/* 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); diff --git a/kernel/trace/trace_sysprof.c b/kernel/trace/trace_sysprof.c index 7c9a2d82a7d..c771af4e8f1 100644 --- a/kernel/trace/trace_sysprof.c +++ b/kernel/trace/trace_sysprof.c @@ -327,5 +327,5 @@ void init_tracer_sysprof_debugfs(struct dentry *d_tracer) d_tracer, NULL, &sysprof_sample_fops); if (entry) return; - pr_warning("Could not create debugfs 'dyn_ftrace_total_info' entry\n"); + pr_warning("Could not create debugfs 'sysprof_sample_period' entry\n"); } -- cgit v1.2.3-70-g09d2 From 098335215a4921a8a54193829eaed602dca24df5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Sat, 21 Mar 2009 02:44:50 -0400 Subject: tracing: fix memory leak in trace_stat If the function profiler does not have any items recorded and one were to cat the function stat file, the kernel would take a BUG with a NULL pointer dereference. Looking further into this, I found that returning NULL from stat_start did not stop the stat logic, and would later call stat_next. This breaks from the way seq_file works, so I looked into fixing the stat code. This is where I noticed that the last next_entry is never freed. It is allocated, and if the stat_next returns NULL, the code breaks out of the loop, unlocks the mutex and exits. We never link the next_entry nor do we free it. Thus it is a real memory leak. This patch rearranges the code a bit to not only fix the memory leak, but also to act more like seq_file where nothing is printed if there is nothing to print. That is, stat_start returns NULL. Signed-off-by: Steven Rostedt --- kernel/trace/trace_stat.c | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-) (limited to 'kernel/trace/trace_stat.c') diff --git a/kernel/trace/trace_stat.c b/kernel/trace/trace_stat.c index 39310e3434e..f71b85b22cf 100644 --- a/kernel/trace/trace_stat.c +++ b/kernel/trace/trace_stat.c @@ -75,7 +75,7 @@ static int stat_seq_init(struct tracer_stat_session *session) { struct trace_stat_list *iter_entry, *new_entry; struct tracer_stat *ts = session->ts; - void *prev_stat; + void *stat; int ret = 0; int i; @@ -85,6 +85,10 @@ static int stat_seq_init(struct tracer_stat_session *session) if (!ts->stat_cmp) ts->stat_cmp = dummy_cmp; + stat = ts->stat_start(); + if (!stat) + goto exit; + /* * The first entry. Actually this is the second, but the first * one (the stat_list head) is pointless. @@ -99,14 +103,19 @@ static int stat_seq_init(struct tracer_stat_session *session) list_add(&new_entry->list, &session->stat_list); - new_entry->stat = ts->stat_start(); - prev_stat = new_entry->stat; + new_entry->stat = stat; /* * 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; + new_entry = kmalloc(sizeof(struct trace_stat_list), GFP_KERNEL); if (!new_entry) { ret = -ENOMEM; @@ -114,11 +123,7 @@ static int stat_seq_init(struct tracer_stat_session *session) } INIT_LIST_HEAD(&new_entry->list); - new_entry->stat = ts->stat_next(prev_stat, i); - - /* End of insertion */ - if (!new_entry->stat) - break; + new_entry->stat = stat; list_for_each_entry(iter_entry, &session->stat_list, list) { @@ -137,8 +142,6 @@ static int stat_seq_init(struct tracer_stat_session *session) break; } } - - prev_stat = new_entry->stat; } exit: mutex_unlock(&session->stat_mutex); -- cgit v1.2.3-70-g09d2 From e6f489013b985b58d096a3091ece0ed579367232 Mon Sep 17 00:00:00 2001 From: Lai Jiangshan Date: Wed, 25 Mar 2009 16:27:17 +0800 Subject: trace_stat: don't call seq_printf() in seq_operation->start() Impact: Fix incorrect way using seq_file's API Use SEQ_START_TOKEN instead of calling ->stat_headers() int seq_operation->start(). Signed-off-by: Lai Jiangshan Acked-by: Steven Rostedt Cc: Alexey Dobriyan LKML-Reference: <49C9EAE5.5070202@cn.fujitsu.com> Signed-off-by: Ingo Molnar --- kernel/trace/trace_stat.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'kernel/trace/trace_stat.c') diff --git a/kernel/trace/trace_stat.c b/kernel/trace/trace_stat.c index f71b85b22cf..8c129dd480a 100644 --- a/kernel/trace/trace_stat.c +++ b/kernel/trace/trace_stat.c @@ -163,7 +163,7 @@ static void *stat_seq_start(struct seq_file *s, loff_t *pos) /* If we are in the beginning of the file, print the headers */ if (!*pos && session->ts->stat_headers) - session->ts->stat_headers(s); + return SEQ_START_TOKEN; return seq_list_start(&session->stat_list, *pos); } @@ -172,6 +172,9 @@ static void *stat_seq_next(struct seq_file *s, void *p, loff_t *pos) { struct tracer_stat_session *session = s->private; + if (p == SEQ_START_TOKEN) + return seq_list_start(&session->stat_list, *pos); + return seq_list_next(p, &session->stat_list, pos); } @@ -186,6 +189,9 @@ 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); } -- cgit v1.2.3-70-g09d2 From 220ba351dfa57eca4bec5ce0098a276446a47958 Mon Sep 17 00:00:00 2001 From: Lai Jiangshan Date: Wed, 25 Mar 2009 16:58:39 +0800 Subject: trace_stat: keep original order Impact: make trace_stat files show items with the original order trace_stat tracer reverse the items, it makes the output looks a little ugly. Example, when we read trace_stat/workqueues, we get cpu#7's stat. at first, and then cpu#6... cpu#0. Signed-off-by: Lai Jiangshan Acked-by: Steven Rostedt Acked-by: Frederic Weisbecker LKML-Reference: <49C9F23F.5040307@cn.fujitsu.com> Signed-off-by: Ingo Molnar --- kernel/trace/trace_stat.c | 18 ++++++++---------- 1 file changed, 8 insertions(+), 10 deletions(-) (limited to 'kernel/trace/trace_stat.c') diff --git a/kernel/trace/trace_stat.c b/kernel/trace/trace_stat.c index 8c129dd480a..acdebd771a9 100644 --- a/kernel/trace/trace_stat.c +++ b/kernel/trace/trace_stat.c @@ -125,23 +125,21 @@ static int stat_seq_init(struct tracer_stat_session *session) INIT_LIST_HEAD(&new_entry->list); new_entry->stat = stat; - list_for_each_entry(iter_entry, &session->stat_list, list) { + list_for_each_entry_reverse(iter_entry, &session->stat_list, + list) { /* Insertion with a descendent sorting */ - if (ts->stat_cmp(new_entry->stat, - iter_entry->stat) > 0) { + if (ts->stat_cmp(iter_entry->stat, + new_entry->stat) >= 0) { - list_add_tail(&new_entry->list, - &iter_entry->list); - break; - - /* The current smaller value */ - } else if (list_is_last(&iter_entry->list, - &session->stat_list)) { 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); } exit: mutex_unlock(&session->stat_mutex); -- cgit v1.2.3-70-g09d2