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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: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Frederic 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: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Masami Hiramatsu 2009-11-03 19:12:30 -05:00 committed by Ingo Molnar
parent a7f4328b91
commit a225a1d911
2 changed files with 40 additions and 30 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

64
tools/perf/builtin-probe.c
View File

@ -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 */
@ -347,36 +347,24 @@ 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)
die("Could not open vmlinux/module file.");
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++) {
@ -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);

6
tools/perf/util/probe-finder.c
View File

@ -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) {