[PATCH 04/38] perf tools: Do not disable source line lookup just because of 1 failure

From: Arnaldo Carvalho de Melo
Date: Wed Dec 04 2013 - 15:12:23 EST


From: Adrian Hunter <adrian.hunter@xxxxxxxxx>

Looking up an ip's source file name and line number does not succeed
always. Current logic disables the lookup for a dso entirely on any
failure. Change it so that disabling never happens if there has ever
been a successful lookup for that dso but disable if the first 123
lookups fail.

Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Mike Galbraith <efault@xxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/1386055390-13757-8-git-send-email-adrian.hunter@xxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/util/dso.c | 1 +
tools/perf/util/dso.h | 1 +
tools/perf/util/srcline.c | 20 ++++++++++++++++----
3 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index 49da9684f635..a0c7c591f4b2 100644
--- a/tools/perf/util/dso.c
+++ b/tools/perf/util/dso.c
@@ -451,6 +451,7 @@ struct dso *dso__new(const char *name)
dso->sorted_by_name = 0;
dso->has_build_id = 0;
dso->has_srcline = 1;
+ dso->a2l_fails = 1;
dso->kernel = DSO_TYPE_USER;
dso->needs_swap = DSO_SWAP__UNSET;
INIT_LIST_HEAD(&dso->node);
diff --git a/tools/perf/util/dso.h b/tools/perf/util/dso.h
index 7142e5261266..384f2d97e38e 100644
--- a/tools/perf/util/dso.h
+++ b/tools/perf/util/dso.h
@@ -79,6 +79,7 @@ struct dso {
struct rb_root cache;
void *a2l;
char *symsrc_filename;
+ unsigned int a2l_fails;
enum dso_kernel_type kernel;
enum dso_swap_type needs_swap;
enum dso_binary_type symtab_type;
diff --git a/tools/perf/util/srcline.c b/tools/perf/util/srcline.c
index 93795f9c2480..0c075560ad46 100644
--- a/tools/perf/util/srcline.c
+++ b/tools/perf/util/srcline.c
@@ -244,6 +244,12 @@ void dso__free_a2l(struct dso *dso __maybe_unused)

#endif /* HAVE_LIBBFD_SUPPORT */

+/*
+ * Number of addr2line failures (without success) before disabling it for that
+ * dso.
+ */
+#define A2L_FAIL_LIMIT 123
+
char *get_srcline(struct dso *dso, unsigned long addr)
{
char *file = NULL;
@@ -268,15 +274,21 @@ char *get_srcline(struct dso *dso, unsigned long addr)
if (!addr2line(dso_name, addr, &file, &line, dso))
goto out;

- if (asprintf(&srcline, "%s:%u", file, line) < 0)
- srcline = SRCLINE_UNKNOWN;
+ if (asprintf(&srcline, "%s:%u", file, line) < 0) {
+ free(file);
+ goto out;
+ }
+
+ dso->a2l_fails = 0;

free(file);
return srcline;

out:
- dso->has_srcline = 0;
- dso__free_a2l(dso);
+ if (dso->a2l_fails && ++dso->a2l_fails > A2L_FAIL_LIMIT) {
+ dso->has_srcline = 0;
+ dso__free_a2l(dso);
+ }
return SRCLINE_UNKNOWN;
}

--
1.8.1.4

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