From 0706f1c48ca8a7ab478090b4e38f2e578ae2bfe0 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 23 Mar 2009 23:12:58 -0400 Subject: [PATCH] tracing: adding function timings to function profiler If the function graph trace is enabled, the function profiler will use it to take the timing of the functions. cat /debug/tracing/trace_stat/functions Function Hit Time -------- --- ---- mwait_idle 127 183028.4 us schedule 26 151997.7 us __schedule 31 151975.1 us sys_wait4 2 74080.53 us do_wait 2 74077.80 us sys_newlstat 138 39929.16 us do_path_lookup 179 39845.79 us vfs_lstat_fd 138 39761.97 us user_path_at 153 39469.58 us path_walk 179 39435.76 us __link_path_walk 189 39143.73 us [...] Note the times are skewed due to the function graph tracer not taking into account schedules. Signed-off-by: Steven Rostedt --- kernel/trace/ftrace.c | 93 ++++++++++++++++++++++++++-- kernel/trace/trace.c | 11 ---- kernel/trace/trace.h | 3 +- kernel/trace/trace_functions_graph.c | 17 ++++- kernel/trace/trace_output.c | 10 +++ kernel/trace/trace_output.h | 2 + 6 files changed, 117 insertions(+), 19 deletions(-) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 24dac448cdc9..a9ccd71fc922 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -33,7 +33,7 @@ #include -#include "trace.h" +#include "trace_output.h" #include "trace_stat.h" #define FTRACE_WARN_ON(cond) \ @@ -246,6 +246,9 @@ struct ftrace_profile { struct hlist_node node; unsigned long ip; unsigned long counter; +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + unsigned long long time; +#endif }; struct ftrace_profile_page { @@ -303,6 +306,22 @@ static void *function_stat_start(struct tracer_stat *trace) return function_stat_next(&profile_pages_start->records[0], 0); } +#ifdef CONFIG_FUNCTION_GRAPH_TRACER +/* function graph compares on total time */ +static int function_stat_cmp(void *p1, void *p2) +{ + struct ftrace_profile *a = p1; + struct ftrace_profile *b = p2; + + if (a->time < b->time) + return -1; + if (a->time > b->time) + return 1; + else + return 0; +} +#else +/* not function graph compares against hits */ static int function_stat_cmp(void *p1, void *p2) { struct ftrace_profile *a = p1; @@ -315,11 +334,17 @@ static int function_stat_cmp(void *p1, void *p2) else return 0; } +#endif static int function_stat_headers(struct seq_file *m) { +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + seq_printf(m, " Function Hit Time\n" + " -------- --- ----\n"); +#else seq_printf(m, " Function Hit\n" " -------- ---\n"); +#endif return 0; } @@ -327,10 +352,25 @@ static int function_stat_show(struct seq_file *m, void *v) { struct ftrace_profile *rec = v; char str[KSYM_SYMBOL_LEN]; +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + static struct trace_seq s; + static DEFINE_MUTEX(mutex); + + mutex_lock(&mutex); + trace_seq_init(&s); + trace_print_graph_duration(rec->time, &s); +#endif kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); + seq_printf(m, " %-30.30s %10lu", str, rec->counter); + +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + seq_printf(m, " "); + trace_print_seq(m, &s); + mutex_unlock(&mutex); +#endif + seq_putc(m, '\n'); - seq_printf(m, " %-30.30s %10lu\n", str, rec->counter); return 0; } @@ -534,11 +574,52 @@ function_profile_call(unsigned long ip, unsigned long parent_ip) local_irq_restore(flags); } +#ifdef CONFIG_FUNCTION_GRAPH_TRACER +static int profile_graph_entry(struct ftrace_graph_ent *trace) +{ + function_profile_call(trace->func, 0); + return 1; +} + +static void profile_graph_return(struct ftrace_graph_ret *trace) +{ + unsigned long flags; + struct ftrace_profile *rec; + + local_irq_save(flags); + rec = ftrace_find_profiled_func(trace->func); + if (rec) + rec->time += trace->rettime - trace->calltime; + local_irq_restore(flags); +} + +static int register_ftrace_profiler(void) +{ + return register_ftrace_graph(&profile_graph_return, + &profile_graph_entry); +} + +static void unregister_ftrace_profiler(void) +{ + unregister_ftrace_graph(); +} +#else static struct ftrace_ops ftrace_profile_ops __read_mostly = { .func = function_profile_call, }; +static int register_ftrace_profiler(void) +{ + return register_ftrace_function(&ftrace_profile_ops); +} + +static void unregister_ftrace_profiler(void) +{ + unregister_ftrace_function(&ftrace_profile_ops); +} +#endif /* CONFIG_FUNCTION_GRAPH_TRACER */ + static ssize_t ftrace_profile_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *ppos) @@ -570,11 +651,15 @@ ftrace_profile_write(struct file *filp, const char __user *ubuf, goto out; } - register_ftrace_function(&ftrace_profile_ops); + ret = register_ftrace_profiler(); + if (ret < 0) { + cnt = ret; + goto out; + } ftrace_profile_enabled = 1; } else { ftrace_profile_enabled = 0; - unregister_ftrace_function(&ftrace_profile_ops); + unregister_ftrace_profiler(); } } out: diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 67c6a21dd427..821bf49771d4 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -402,17 +402,6 @@ static ssize_t trace_seq_to_buffer(struct trace_seq *s, void *buf, size_t cnt) return cnt; } -static void -trace_print_seq(struct seq_file *m, struct trace_seq *s) -{ - int len = s->len >= PAGE_SIZE ? PAGE_SIZE - 1 : s->len; - - s->buffer[len] = 0; - seq_puts(m, s->buffer); - - trace_seq_init(s); -} - /** * update_max_tr - snapshot all trace buffers from global_trace to max_tr * @tr: tracer diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index d7410bbb9a80..c66ca3b66050 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -605,6 +605,8 @@ extern unsigned long trace_flags; /* Standard output formatting function used for function return traces */ #ifdef CONFIG_FUNCTION_GRAPH_TRACER extern enum print_line_t print_graph_function(struct trace_iterator *iter); +extern enum print_line_t +trace_print_graph_duration(unsigned long long duration, struct trace_seq *s); #ifdef CONFIG_DYNAMIC_FTRACE /* TODO: make this variable */ @@ -636,7 +638,6 @@ static inline int ftrace_graph_addr(unsigned long addr) return 1; } #endif /* CONFIG_DYNAMIC_FTRACE */ - #else /* CONFIG_FUNCTION_GRAPH_TRACER */ static inline enum print_line_t print_graph_function(struct trace_iterator *iter) diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index d28687e7b3a7..85bba0f018b0 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -426,8 +426,8 @@ print_graph_irq(struct trace_iterator *iter, unsigned long addr, return TRACE_TYPE_HANDLED; } -static enum print_line_t -print_graph_duration(unsigned long long duration, struct trace_seq *s) +enum print_line_t +trace_print_graph_duration(unsigned long long duration, struct trace_seq *s) { unsigned long nsecs_rem = do_div(duration, 1000); /* log10(ULONG_MAX) + '\0' */ @@ -464,12 +464,23 @@ print_graph_duration(unsigned long long duration, struct trace_seq *s) if (!ret) return TRACE_TYPE_PARTIAL_LINE; } + return TRACE_TYPE_HANDLED; +} + +static enum print_line_t +print_graph_duration(unsigned long long duration, struct trace_seq *s) +{ + int ret; + + ret = trace_print_graph_duration(duration, s); + if (ret != TRACE_TYPE_HANDLED) + return ret; ret = trace_seq_printf(s, "| "); if (!ret) return TRACE_TYPE_PARTIAL_LINE; - return TRACE_TYPE_HANDLED; + return TRACE_TYPE_HANDLED; } /* Case of a leaf function on its call entry */ diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index 19261fdd2455..a3b6e3fd7044 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -19,6 +19,16 @@ static struct hlist_head event_hash[EVENT_HASHSIZE] __read_mostly; static int next_event_type = __TRACE_LAST_TYPE + 1; +void trace_print_seq(struct seq_file *m, struct trace_seq *s) +{ + int len = s->len >= PAGE_SIZE ? PAGE_SIZE - 1 : s->len; + + s->buffer[len] = 0; + seq_puts(m, s->buffer); + + trace_seq_init(s); +} + enum print_line_t trace_print_bprintk_msg_only(struct trace_iterator *iter) { struct trace_seq *s = &iter->seq; diff --git a/kernel/trace/trace_output.h b/kernel/trace/trace_output.h index 35c422fb51a9..1eac2973374e 100644 --- a/kernel/trace/trace_output.h +++ b/kernel/trace/trace_output.h @@ -20,6 +20,8 @@ trace_print_bprintk_msg_only(struct trace_iterator *iter); extern enum print_line_t trace_print_printk_msg_only(struct trace_iterator *iter); +extern void trace_print_seq(struct seq_file *m, struct trace_seq *s); + extern int trace_seq_printf(struct trace_seq *s, const char *fmt, ...) __attribute__ ((format (printf, 2, 3))); extern int -- GitLab