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Commit d761b08b authored by Masami Hiramatsu's avatar Masami Hiramatsu Committed by Ingo Molnar
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perf probe: Reject second attempt of adding same-name event 



Reject second attempt of adding same-name event. This patch
also provides --force option which allows user to add additional
probe events on the same-name event.

e.g.
(the first attempt : success)
 ./perf probe schedule
 Added new event:
   probe:schedule                           (on schedule+0)

(the second attempt : failure)
 ./perf probe schedule:11
 Error: event "schedule" already exists. (Use -f to force duplicates.)
   Fatal: Can't add new event.

(the second attempt with -f : successfully added)
 ./perf probe -f schedule:11
 Added new event:
   probe:schedule_1                         (on schedule+45)

Signed-off-by: default avatarMasami Hiramatsu <mhiramat@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: systemtap <systemtap@sources.redhat.com>
Cc: DLE <dle-develop@lists.sourceforge.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20091215153225.17436.15166.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent af663d75

tools/perf/builtin-probe.c

+5 −1
Original line number Diff line number Diff line
@@ -61,6 +61,7 @@ static struct { 
	char *release;

	bool need_dwarf;

	bool list_events;

	bool force_add;

	int nr_probe;

	struct probe_point probes[MAX_PROBES];

	struct strlist *dellist;
@@ -192,6 +193,8 @@ static const struct option options[] = { 
#endif

		"\t\t\tkprobe-tracer argument format.)\n",

		opt_add_probe_event),

	OPT_BOOLEAN('f', "force", &session.force_add, "forcibly add events"

		    " with existing name"),

	OPT_END()

};
@@ -294,7 +297,8 @@ int cmd_probe(int argc, const char **argv, const char *prefix __used) 
	}



	/* Settng up probe points */

	add_trace_kprobe_events(session.probes, session.nr_probe);

	add_trace_kprobe_events(session.probes, session.nr_probe,

				session.force_add);

	return 0;

}

tools/perf/util/probe-event.c

+21 −3
Original line number Diff line number Diff line
@@ -482,7 +482,7 @@ static void write_trace_kprobe_event(int fd, const char *buf) 
}



static void get_new_event_name(char *buf, size_t len, const char *base,

			       struct strlist *namelist)

			       struct strlist *namelist, bool allow_suffix)

{

	int i, ret;
@@ -493,6 +493,12 @@ static void get_new_event_name(char *buf, size_t len, const char *base, 
	if (!strlist__has_entry(namelist, buf))

		return;



	if (!allow_suffix) {

		pr_warning("Error: event \"%s\" already exists. "

			   "(Use -f to force duplicates.)\n", base);

		die("Can't add new event.");

	}



	/* Try to add suffix */

	for (i = 1; i < MAX_EVENT_INDEX; i++) {

		ret = e_snprintf(buf, len, "%s_%d", base, i);
@@ -505,13 +511,15 @@ static void get_new_event_name(char *buf, size_t len, const char *base, 
		die("Too many events are on the same function.");

}



void add_trace_kprobe_events(struct probe_point *probes, int nr_probes)

void add_trace_kprobe_events(struct probe_point *probes, int nr_probes,

			     bool force_add)

{

	int i, j, fd;

	struct probe_point *pp;

	char buf[MAX_CMDLEN];

	char event[64];

	struct strlist *namelist;

	bool allow_suffix;



	fd = open_kprobe_events(O_RDWR, O_APPEND);

	/* Get current event names */
@@ -524,9 +532,12 @@ void add_trace_kprobe_events(struct probe_point *probes, int nr_probes) 
		if (!pp->group)

			pp->group = strdup(PERFPROBE_GROUP);

		DIE_IF(!pp->event || !pp->group);

		/* If force_add is true, suffix search is allowed */

		allow_suffix = force_add;

		for (i = 0; i < pp->found; i++) {

			/* Get an unused new event name */

			get_new_event_name(event, 64, pp->event, namelist);

			get_new_event_name(event, 64, pp->event, namelist,

					   allow_suffix);

			snprintf(buf, MAX_CMDLEN, "%c:%s/%s %s\n",

				 pp->retprobe ? 'r' : 'p',

				 pp->group, event,
@@ -538,6 +549,13 @@ void add_trace_kprobe_events(struct probe_point *probes, int nr_probes) 
			show_perf_probe_event(event, buf, pp);

			/* Add added event name to namelist */

			strlist__add(namelist, event);

			/*

			 * Probes after the first probe which comes from same

			 * user input are always allowed to add suffix, because

			 * there might be several addresses corresponding to

			 * one code line.

			 */

			allow_suffix = true;

		}

	}

	/* Show how to use the event. */

tools/perf/util/probe-event.h

+2 −1
Original line number Diff line number Diff line
@@ -10,7 +10,8 @@ extern void parse_perf_probe_event(const char *str, struct probe_point *pp, 
extern int synthesize_perf_probe_event(struct probe_point *pp);

extern void parse_trace_kprobe_event(const char *str, struct probe_point *pp);

extern int synthesize_trace_kprobe_event(struct probe_point *pp);

extern void add_trace_kprobe_events(struct probe_point *probes, int nr_probes);

extern void add_trace_kprobe_events(struct probe_point *probes, int nr_probes,

				    bool force_add);

extern void del_trace_kprobe_events(struct strlist *dellist);

extern void show_perf_probe_events(void);