From 0706f1c48ca8a7ab478090b4e38f2e578ae2bfe0 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 23 Mar 2009 23:12:58 -0400 Subject: 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 ++++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 89 insertions(+), 4 deletions(-) (limited to 'kernel/trace/ftrace.c') diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 24dac44..a9ccd71 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: -- cgit v1.1