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>
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2 changed files with 40 additions and 30 deletions
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@ -189,7 +189,7 @@ static void parse_probe_event(const char *str)
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/* Parse probe point */
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/* Parse probe point */
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parse_probe_point(argv[0], pp);
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parse_probe_point(argv[0], pp);
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free(argv[0]);
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free(argv[0]);
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if (pp->file)
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if (pp->file || pp->line)
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session.need_dwarf = 1;
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session.need_dwarf = 1;
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/* Copy arguments */
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/* Copy arguments */
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@ -347,36 +347,24 @@ int cmd_probe(int argc, const char **argv, const char *prefix __used)
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if (session.nr_probe == 0)
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if (session.nr_probe == 0)
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usage_with_options(probe_usage, options);
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usage_with_options(probe_usage, options);
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#ifdef NO_LIBDWARF
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if (session.need_dwarf)
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if (session.need_dwarf)
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semantic_error("Dwarf-analysis is not supported");
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#ifdef NO_LIBDWARF
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#endif
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semantic_error("Debuginfo-analysis is not supported");
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#else /* !NO_LIBDWARF */
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/* Synthesize probes without dwarf */
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pr_info("Some probes require debuginfo.\n");
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for (j = 0; j < session.nr_probe; j++) {
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#ifndef NO_LIBDWARF
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if (!session.probes[j].retprobe) {
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session.need_dwarf = 1;
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continue;
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}
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#endif
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ret = synthesize_probe_event(&session.probes[j]);
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if (ret == -E2BIG)
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semantic_error("probe point is too long.");
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else if (ret < 0)
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die("Failed to synthesize a probe point.");
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}
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#ifndef NO_LIBDWARF
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if (!session.need_dwarf)
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goto setup_probes;
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if (session.vmlinux)
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if (session.vmlinux)
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fd = open(session.vmlinux, O_RDONLY);
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fd = open(session.vmlinux, O_RDONLY);
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else
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else
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fd = open_default_vmlinux();
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fd = open_default_vmlinux();
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if (fd < 0)
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if (fd < 0) {
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die("Could not open vmlinux/module file.");
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if (session.need_dwarf)
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die("Could not open vmlinux/module file.");
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pr_warning("Could not open vmlinux/module file."
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" Try to use symbols.\n");
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goto end_dwarf;
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}
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/* Searching probe points */
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/* Searching probe points */
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for (j = 0; j < session.nr_probe; j++) {
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for (j = 0; j < session.nr_probe; j++) {
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@ -386,14 +374,34 @@ int cmd_probe(int argc, const char **argv, const char *prefix __used)
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lseek(fd, SEEK_SET, 0);
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lseek(fd, SEEK_SET, 0);
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ret = find_probepoint(fd, pp);
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ret = find_probepoint(fd, pp);
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if (ret <= 0)
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if (ret < 0) {
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die("No probe point found.\n");
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if (session.need_dwarf)
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die("Could not analyze debuginfo.");
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pr_warning("An error occurred in debuginfo analysis. Try to use symbols.\n");
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break;
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}
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if (ret == 0) /* No error but failed to find probe point. */
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die("No probe point found.");
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}
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}
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close(fd);
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close(fd);
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setup_probes:
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end_dwarf:
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#endif /* !NO_LIBDWARF */
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#endif /* !NO_LIBDWARF */
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/* Synthesize probes without dwarf */
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for (j = 0; j < session.nr_probe; j++) {
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pp = &session.probes[j];
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if (pp->found) /* This probe is already found. */
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continue;
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ret = synthesize_probe_event(pp);
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if (ret == -E2BIG)
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semantic_error("probe point is too long.");
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else if (ret < 0)
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die("Failed to synthesize a probe point.");
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}
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/* Settng up probe points */
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/* Settng up probe points */
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snprintf(buf, MAX_CMDLEN, "%s/../kprobe_events", debugfs_path);
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snprintf(buf, MAX_CMDLEN, "%s/../kprobe_events", debugfs_path);
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fd = open(buf, O_WRONLY, O_APPEND);
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fd = open(buf, O_WRONLY, O_APPEND);
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@ -687,8 +687,10 @@ int find_probepoint(int fd, struct probe_point *pp)
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struct probe_finder pf = {.pp = pp};
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struct probe_finder pf = {.pp = pp};
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ret = dwarf_init(fd, DW_DLC_READ, 0, 0, &__dw_debug, &__dw_error);
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ret = dwarf_init(fd, DW_DLC_READ, 0, 0, &__dw_debug, &__dw_error);
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if (ret != DW_DLV_OK)
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if (ret != DW_DLV_OK) {
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die("No dwarf info found in the vmlinux - please rebuild with CONFIG_DEBUG_INFO.\n");
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pr_warning("No dwarf info found in the vmlinux - please rebuild with CONFIG_DEBUG_INFO.\n");
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return -ENOENT;
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}
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pp->found = 0;
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pp->found = 0;
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while (++cu_number) {
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while (++cu_number) {
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