From: Sukadev Bhattiprolu <suka...@linux.vnet.ibm.com>
Cache the DWARF debug info for DSO so we don't have to rebuild it for each
address in the DSO.
Note that dso__new() uses calloc() so don't need to set dso->dwfl to NULL.
$ /tmp/perf.orig --version
perf version 3.18.rc1.gc2661b8
$ /tmp/perf.new --version
perf version 3.18.rc1.g402d62
$ perf stat -e cycles,instructions /tmp/perf.orig report -g > orig
Performance counter stats for '/tmp/perf.orig report -g':
6,428,177,183 cycles # 0.000 GHz
4,176,288,391 instructions # 0.65 insns per cycle
1.840666132 seconds time elapsed
$ perf stat -e cycles,instructions /tmp/perf.new report -g > new
Performance counter stats for '/tmp/perf.new report -g':
305,773,142 cycles # 0.000 GHz
276,048,272 instructions # 0.90 insns per cycle
0.087693543 seconds time elapsed
$ diff orig new
$
Changelog[v2]:
[Arnaldo Carvalho] Cache in existing global objects rather than create
new static/globals in functions.
Reported-by: Anton Blanchard <an...@samba.org>
Signed-off-by: Sukadev Bhattiprolu <suka...@linux.vnet.ibm.com>
Cc: Anton Blanchard <an...@au1.ibm.com>
Cc: Jiri Olsa <jo...@redhat.com>
Link: http://lkml.kernel.org/r/20141022000958.gb2...@us.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com>
---
tools/perf/arch/powerpc/util/skip-callchain-idx.c | 33 +++++++++++++++--------
tools/perf/util/dso.h | 1 +
2 files changed, 23 insertions(+), 11 deletions(-)
diff --git a/tools/perf/arch/powerpc/util/skip-callchain-idx.c
b/tools/perf/arch/powerpc/util/skip-callchain-idx.c
index d73ef8bb08c7..9892b0f0bec4 100644
--- a/tools/perf/arch/powerpc/util/skip-callchain-idx.c
+++ b/tools/perf/arch/powerpc/util/skip-callchain-idx.c
@@ -145,7 +145,7 @@ static Dwarf_Frame *get_dwarf_frame(Dwfl_Module *mod,
Dwarf_Addr pc)
* yet used)
* -1 in case of errors
*/
-static int check_return_addr(const char *exec_file, Dwarf_Addr pc)
+static int check_return_addr(struct dso *dso, Dwarf_Addr pc)
{
int rc = -1;
Dwfl *dwfl;
@@ -156,15 +156,27 @@ static int check_return_addr(const char *exec_file,
Dwarf_Addr pc)
Dwarf_Addr end = pc;
bool signalp;
- dwfl = dwfl_begin(&offline_callbacks);
- if (!dwfl) {
- pr_debug("dwfl_begin() failed: %s\n", dwarf_errmsg(-1));
- return -1;
- }
+ dwfl = dso->dwfl;
- if (dwfl_report_offline(dwfl, "", exec_file, -1) == NULL) {
- pr_debug("dwfl_report_offline() failed %s\n", dwarf_errmsg(-1));
- goto out;
+ if (!dwfl) {
+ dwfl = dwfl_begin(&offline_callbacks);
+ if (!dwfl) {
+ pr_debug("dwfl_begin() failed: %s\n", dwarf_errmsg(-1));
+ return -1;
+ }
+
+ if (dwfl_report_offline(dwfl, "", dso->long_name, -1) == NULL) {
+ pr_debug("dwfl_report_offline() failed %s\n",
+ dwarf_errmsg(-1));
+ /*
+ * We normally cache the DWARF debug info and never
+ * call dwfl_end(). But to prevent fd leak, free in
+ * case of error.
+ */
+ dwfl_end(dwfl);
+ goto out;
+ }
+ dso->dwfl = dwfl;
}
mod = dwfl_addrmodule(dwfl, pc);
@@ -194,7 +206,6 @@ static int check_return_addr(const char *exec_file,
Dwarf_Addr pc)
rc = check_return_reg(ra_regno, frame);
out:
- dwfl_end(dwfl);
return rc;
}
@@ -246,7 +257,7 @@ int arch_skip_callchain_idx(struct machine *machine, struct
thread *thread,
return skip_slot;
}
- rc = check_return_addr(dso->long_name, ip);
+ rc = check_return_addr(dso, ip);
pr_debug("DSO %s, nr %" PRIx64 ", ip 0x%" PRIx64 "rc %d\n",
dso->long_name, chain->nr, ip, rc);
diff --git a/tools/perf/util/dso.h b/tools/perf/util/dso.h
index acb651acc7fd..3c9b391493f9 100644
--- a/tools/perf/util/dso.h
+++ b/tools/perf/util/dso.h
@@ -127,6 +127,7 @@ struct dso {
const char *long_name;
u16 long_name_len;
u16 short_name_len;
+ void *dwfl; /* DWARF debug info */
/* dso data file */
struct {
--
1.9.3
--
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