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Commit a225a1d9 authored by Masami Hiramatsu's avatar Masami Hiramatsu Committed by Ingo Molnar
Browse files

perf/probes: Fall back to non-dwarf if possible 



Fall back to non-dwarf probe point if the probe definition may
not need dwarf analysis, when perf can't find vmlinux/debuginfo.
This might skip some inlined code of target function.

Signed-off-by: default avatarMasami Hiramatsu <mhiramat@redhat.com>
Acked-by: default avatarFrederic Weisbecker <fweisbec@gmail.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>
LKML-Reference: <20091104001229.3454.63987.stgit@harusame>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent a7f4328b

tools/perf/builtin-probe.c

+36 −28
Original line number Diff line number Diff line
@@ -189,7 +189,7 @@ static void parse_probe_event(const char *str) 
	/* Parse probe point */

	parse_probe_point(argv[0], pp);

	free(argv[0]);

	if (pp->file)

	if (pp->file || pp->line)

		session.need_dwarf = 1;



	/* Copy arguments */
@@ -347,37 +347,25 @@ int cmd_probe(int argc, const char **argv, const char *prefix __used) 
	if (session.nr_probe == 0)

		usage_with_options(probe_usage, options);



#ifdef NO_LIBDWARF

	if (session.need_dwarf)

		semantic_error("Dwarf-analysis is not supported");

#endif



	/* Synthesize probes without dwarf */

	for (j = 0; j < session.nr_probe; j++) {

#ifndef NO_LIBDWARF

		if (!session.probes[j].retprobe) {

			session.need_dwarf = 1;

			continue;

		}

#endif

		ret = synthesize_probe_event(&session.probes[j]);

		if (ret == -E2BIG)

			semantic_error("probe point is too long.");

		else if (ret < 0)

			die("Failed to synthesize a probe point.");

	}



#ifndef NO_LIBDWARF

	if (!session.need_dwarf)

		goto setup_probes;

#ifdef NO_LIBDWARF

		semantic_error("Debuginfo-analysis is not supported");

#else	/* !NO_LIBDWARF */

		pr_info("Some probes require debuginfo.\n");



	if (session.vmlinux)

		fd = open(session.vmlinux, O_RDONLY);

	else

		fd = open_default_vmlinux();

	if (fd < 0)

	if (fd < 0) {

		if (session.need_dwarf)

			die("Could not open vmlinux/module file.");



		pr_warning("Could not open vmlinux/module file."

			   " Try to use symbols.\n");

		goto end_dwarf;

	}



	/* Searching probe points */

	for (j = 0; j < session.nr_probe; j++) {

		pp = &session.probes[j];
@@ -386,14 +374,34 @@ int cmd_probe(int argc, const char **argv, const char *prefix __used) 


		lseek(fd, SEEK_SET, 0);

		ret = find_probepoint(fd, pp);

		if (ret <= 0)

			die("No probe point found.\n");

		if (ret < 0) {

			if (session.need_dwarf)

				die("Could not analyze debuginfo.");



			pr_warning("An error occurred in debuginfo analysis. Try to use symbols.\n");

			break;

		}

		if (ret == 0)	/* No error but failed to find probe point. */

			die("No probe point found.");

	}

	close(fd);



setup_probes:

end_dwarf:

#endif /* !NO_LIBDWARF */



	/* Synthesize probes without dwarf */

	for (j = 0; j < session.nr_probe; j++) {

		pp = &session.probes[j];

		if (pp->found)	/* This probe is already found. */

			continue;



		ret = synthesize_probe_event(pp);

		if (ret == -E2BIG)

			semantic_error("probe point is too long.");

		else if (ret < 0)

			die("Failed to synthesize a probe point.");

	}



	/* Settng up probe points */

	snprintf(buf, MAX_CMDLEN, "%s/../kprobe_events", debugfs_path);

	fd = open(buf, O_WRONLY, O_APPEND);

tools/perf/util/probe-finder.c

+4 −2
Original line number Diff line number Diff line
@@ -687,8 +687,10 @@ int find_probepoint(int fd, struct probe_point *pp) 
	struct probe_finder pf = {.pp = pp};



	ret = dwarf_init(fd, DW_DLC_READ, 0, 0, &__dw_debug, &__dw_error);

	if (ret != DW_DLV_OK)

		die("No dwarf info found in the vmlinux - please rebuild with CONFIG_DEBUG_INFO.\n");

	if (ret != DW_DLV_OK) {

		pr_warning("No dwarf info found in the vmlinux - please rebuild with CONFIG_DEBUG_INFO.\n");

		return -ENOENT;

	}



	pp->found = 0;

	while (++cu_number) {