Add profiling interaces for each kprobes event. This interface provides how many times each probe hit or missed.
Changes from v12: - Reformat profile data. Signed-off-by: Masami Hiramatsu <[email protected]> Cc: Ananth N Mavinakayanahalli <[email protected]> Cc: Christoph Hellwig <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Frederic Weisbecker <[email protected]> Cc: Tom Zanussi <[email protected]> Cc: Li Zefan <[email protected]> --- Documentation/trace/kprobetrace.txt | 8 +++++++ kernel/trace/trace_kprobe.c | 43 +++++++++++++++++++++++++++++++++++ 2 files changed, 51 insertions(+), 0 deletions(-) diff --git a/Documentation/trace/kprobetrace.txt b/Documentation/trace/kprobetrace.txt index 437ad49..9c6be05 100644 --- a/Documentation/trace/kprobetrace.txt +++ b/Documentation/trace/kprobetrace.txt @@ -69,6 +69,14 @@ filter: names and field names for describing filters. +Event Profiling +--------------- + You can check the total number of probe hits and probe miss-hits via +/sys/kernel/debug/tracing/kprobe_profile. + The first column is event name, the second is the number of probe hits, +the third is the number of probe miss-hits. + + Usage examples -------------- To add a probe as a new event, write a new definition to kprobe_events diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 9f9f161..aedf25a 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -178,6 +178,7 @@ struct trace_probe { struct kprobe kp; struct kretprobe rp; }; + unsigned long nhit; const char *symbol; /* symbol name */ struct ftrace_event_call call; unsigned int nr_args; @@ -766,6 +767,37 @@ static const struct file_operations kprobe_events_ops = { .write = probes_write, }; +/* Probes profiling interfaces */ +static int probes_profile_seq_show(struct seq_file *m, void *v) +{ + struct trace_probe *tp = v; + + seq_printf(m, " %-44s %15lu %15lu\n", tp->call.name, tp->nhit, + probe_is_return(tp) ? tp->rp.kp.nmissed : tp->kp.nmissed); + + return 0; +} + +static const struct seq_operations profile_seq_op = { + .start = probes_seq_start, + .next = probes_seq_next, + .stop = probes_seq_stop, + .show = probes_profile_seq_show +}; + +static int profile_open(struct inode *inode, struct file *file) +{ + return seq_open(file, &profile_seq_op); +} + +static const struct file_operations kprobe_profile_ops = { + .owner = THIS_MODULE, + .open = profile_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; + /* Kprobe handler */ static __kprobes int kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs) { @@ -776,6 +808,8 @@ static __kprobes int kprobe_trace_func(struct kprobe *kp, struct pt_regs *regs) unsigned long irq_flags; struct ftrace_event_call *call = &tp->call; + tp->nhit++; + local_save_flags(irq_flags); pc = preempt_count(); @@ -1152,9 +1186,18 @@ static __init int init_kprobe_trace(void) entry = debugfs_create_file("kprobe_events", 0644, d_tracer, NULL, &kprobe_events_ops); + /* Event list interface */ if (!entry) pr_warning("Could not create debugfs " "'kprobe_events' entry\n"); + + /* Profile interface */ + entry = debugfs_create_file("kprobe_profile", 0444, d_tracer, + NULL, &kprobe_profile_ops); + + if (!entry) + pr_warning("Could not create debugfs " + "'kprobe_profile' entry\n"); return 0; } fs_initcall(init_kprobe_trace); -- Masami Hiramatsu Software Engineer Hitachi Computer Products (America), Inc. Software Solutions Division e-mail: [email protected] -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
