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Commit ef4a3565 authored by Masami Hiramatsu's avatar Masami Hiramatsu Committed by Arnaldo Carvalho de Melo
Browse files

perf probe: Add --max-probes option 



Add --max-probes option to change the maximum limit of
findable probe points per event, since inlined function can be
expanded into thousands of probe points. Default value is 128.

Signed-off-by: default avatarMasami Hiramatsu <mhiramat@redhat.com>
Suggested-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <20100421195640.24664.62984.stgit@localhost6.localdomain6>
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 5d1ee041

tools/perf/Documentation/perf-probe.txt

+3 −0
Original line number Diff line number Diff line
@@ -62,6 +62,9 @@ OPTIONS 
	Dry run. With this option, --add and --del doesn't execute actual

	adding and removal operations.



--max-probes::

	Set the maximum number of probe points for an event. Default is 128.



PROBE SYNTAX

------------

Probe points are defined by following syntax.

tools/perf/builtin-probe.c

+8 −1
Original line number Diff line number Diff line
@@ -54,6 +54,7 @@ static struct { 
	struct perf_probe_event events[MAX_PROBES];

	struct strlist *dellist;

	struct line_range line_range;

	int max_probe_points;

} params;
@@ -179,6 +180,8 @@ static const struct option options[] = { 
		   "file", "vmlinux pathname"),

#endif

	OPT__DRY_RUN(&probe_event_dry_run),

	OPT_INTEGER('\0', "max-probes", &params.max_probe_points,

		 "Set how many probe points can be found for a probe."),

	OPT_END()

};
@@ -200,6 +203,9 @@ int cmd_probe(int argc, const char **argv, const char *prefix __used) 
		}

	}



	if (params.max_probe_points == 0)

		params.max_probe_points = MAX_PROBES;



	if ((!params.nevents && !params.dellist && !params.list_events &&

	     !params.show_lines))

		usage_with_options(probe_usage, options);
@@ -246,7 +252,8 @@ int cmd_probe(int argc, const char **argv, const char *prefix __used) 


	if (params.nevents) {

		ret = add_perf_probe_events(params.events, params.nevents,

					    params.force_add);

					    params.force_add,

					    params.max_probe_points);

		if (ret < 0) {

			pr_err("  Error: Failed to add events. (%d)\n", ret);

			return ret;

tools/perf/util/probe-event.c

+10 −7
Original line number Diff line number Diff line
@@ -150,7 +150,8 @@ static int convert_to_perf_probe_point(struct kprobe_trace_point *tp, 


/* Try to find perf_probe_event with debuginfo */

static int try_to_find_kprobe_trace_events(struct perf_probe_event *pev,

					   struct kprobe_trace_event **tevs)

					   struct kprobe_trace_event **tevs,

					   int max_tevs)

{

	bool need_dwarf = perf_probe_event_need_dwarf(pev);

	int fd, ntevs;
@@ -166,7 +167,7 @@ static int try_to_find_kprobe_trace_events(struct perf_probe_event *pev, 
	}



	/* Searching trace events corresponding to probe event */

	ntevs = find_kprobe_trace_events(fd, pev, tevs);

	ntevs = find_kprobe_trace_events(fd, pev, tevs, max_tevs);

	close(fd);



	if (ntevs > 0) {	/* Succeeded to find trace events */
@@ -318,7 +319,8 @@ static int convert_to_perf_probe_point(struct kprobe_trace_point *tp, 
}



static int try_to_find_kprobe_trace_events(struct perf_probe_event *pev,

				struct kprobe_trace_event **tevs __unused)

				struct kprobe_trace_event **tevs __unused,

				int max_tevs __unused)

{

	if (perf_probe_event_need_dwarf(pev)) {

		pr_warning("Debuginfo-analysis is not supported.\n");
@@ -1408,14 +1410,15 @@ static int __add_kprobe_trace_events(struct perf_probe_event *pev, 
}



static int convert_to_kprobe_trace_events(struct perf_probe_event *pev,

					  struct kprobe_trace_event **tevs)

					  struct kprobe_trace_event **tevs,

					  int max_tevs)

{

	struct symbol *sym;

	int ret = 0, i;

	struct kprobe_trace_event *tev;



	/* Convert perf_probe_event with debuginfo */

	ret = try_to_find_kprobe_trace_events(pev, tevs);

	ret = try_to_find_kprobe_trace_events(pev, tevs, max_tevs);

	if (ret != 0)

		return ret;
@@ -1487,7 +1490,7 @@ struct __event_package { 
};



int add_perf_probe_events(struct perf_probe_event *pevs, int npevs,

			  bool force_add)

			  bool force_add, int max_tevs)

{

	int i, j, ret;

	struct __event_package *pkgs;
@@ -1506,7 +1509,7 @@ int add_perf_probe_events(struct perf_probe_event *pevs, int npevs, 
		pkgs[i].pev = &pevs[i];

		/* Convert with or without debuginfo */

		ret  = convert_to_kprobe_trace_events(pkgs[i].pev,

						      &pkgs[i].tevs);

						      &pkgs[i].tevs, max_tevs);

		if (ret < 0)

			goto end;

		pkgs[i].ntevs = ret;

tools/perf/util/probe-event.h

+2 −2
Original line number Diff line number Diff line
@@ -115,8 +115,8 @@ extern void clear_kprobe_trace_event(struct kprobe_trace_event *tev); 
extern int parse_line_range_desc(const char *cmd, struct line_range *lr);





extern int add_perf_probe_events(struct perf_probe_event *pevs, int ntevs,

				 bool force_add);

extern int add_perf_probe_events(struct perf_probe_event *pevs, int npevs,

				 bool force_add, int max_probe_points);

extern int del_perf_probe_events(struct strlist *dellist);

extern int show_perf_probe_events(void);

extern int show_line_range(struct line_range *lr);

tools/perf/util/probe-finder.c

+6 −5
Original line number Diff line number Diff line
@@ -626,8 +626,9 @@ static int convert_probe_point(Dwarf_Die *sp_die, struct probe_finder *pf) 
	Dwarf_Attribute fb_attr;

	size_t nops;



	if (pf->ntevs == MAX_PROBES) {

		pr_warning("Too many( > %d) probe point found.\n", MAX_PROBES);

	if (pf->ntevs == pf->max_tevs) {

		pr_warning("Too many( > %d) probe point found.\n",

			   pf->max_tevs);

		return -ERANGE;

	}

	tev = &pf->tevs[pf->ntevs++];
@@ -932,9 +933,9 @@ static int find_probe_point_by_func(struct probe_finder *pf) 


/* Find kprobe_trace_events specified by perf_probe_event from debuginfo */

int find_kprobe_trace_events(int fd, struct perf_probe_event *pev,

			     struct kprobe_trace_event **tevs)

			     struct kprobe_trace_event **tevs, int max_tevs)

{

	struct probe_finder pf = {.pev = pev};

	struct probe_finder pf = {.pev = pev, .max_tevs = max_tevs};

	struct perf_probe_point *pp = &pev->point;

	Dwarf_Off off, noff;

	size_t cuhl;
@@ -942,7 +943,7 @@ int find_kprobe_trace_events(int fd, struct perf_probe_event *pev, 
	Dwarf *dbg;

	int ret = 0;



	pf.tevs = zalloc(sizeof(struct kprobe_trace_event) * MAX_PROBES);

	pf.tevs = zalloc(sizeof(struct kprobe_trace_event) * max_tevs);

	if (pf.tevs == NULL)

		return -ENOMEM;

	*tevs = pf.tevs;