Commit-ID: 8bd508b001629a5d836987d9a0702a6bfc4fc705
Gitweb: http://git.kernel.org/tip/8bd508b001629a5d836987d9a0702a6bfc4fc705
Author: Jiri Olsa <jolsa@xxxxxxxxxx>
AuthorDate: Thu, 19 Nov 2015 14:01:19 +0100
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Mon, 23 Nov 2015 18:31:13 -0300
perf callchain: Add order support for libdw DWARF unwinder
As reported by Milian, currently for DWARF unwind (both libdw and
libunwind) we display callchain in callee order only.
Adding the support to follow callchain order setup to libdw DWARF
unwinder, so we could get following output for report:
$ perf record --call-graph dwarf ls
...
$ perf report --no-children --stdio
21.12% ls libc-2.21.so [.] __strcoll_l
|
---__strcoll_l
mpsort_with_tmp
mpsort_with_tmp
mpsort_with_tmp
sort_files
main
__libc_start_main
_start
$ perf report --stdio --no-children -g caller
21.12% ls libc-2.21.so [.] __strcoll_l
|
---_start
__libc_start_main
main
sort_files
mpsort_with_tmp
mpsort_with_tmp
mpsort_with_tmp
__strcoll_l
Reported-and-Tested-by: Milian Wolff <milian.wolff@xxxxxxxx>
Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Tested-by: Wang Nan <wangnan0@xxxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Jan Kratochvil <jkratoch@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/20151119130119.GA26617@xxxxxxxxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/util/unwind-libdw.c | 53 ++++++++++++++++++++++++++++++------------
tools/perf/util/unwind-libdw.h | 2 ++
2 files changed, 40 insertions(+), 15 deletions(-)
diff --git a/tools/perf/util/unwind-libdw.c b/tools/perf/util/unwind-libdw.c
index 2dcfe9a..db8142b 100644
--- a/tools/perf/util/unwind-libdw.c
+++ b/tools/perf/util/unwind-libdw.c
@@ -11,6 +11,7 @@
#include <linux/types.h>
#include "event.h"
#include "perf_regs.h"
+#include "callchain.h"
static char *debuginfo_path;
@@ -52,25 +53,28 @@ static int report_module(u64 ip, struct unwind_info *ui)
return __report_module(&al, ip, ui);
}
+/*
+ * Store all entries within entries array,
+ * we will process it after we finish unwind.
+ */
static int entry(u64 ip, struct unwind_info *ui)
{
- struct unwind_entry e;
+ struct unwind_entry *e = &ui->entries[ui->idx++];
struct addr_location al;
if (__report_module(&al, ip, ui))
return -1;
- e.ip = ip;
- e.map = al.map;
- e.sym = al.sym;
+ e->ip = ip;
+ e->map = al.map;
+ e->sym = al.sym;
pr_debug("unwind: %s:ip = 0x%" PRIx64 " (0x%" PRIx64 ")\n",
al.sym ? al.sym->name : "''",
ip,
al.map ? al.map->map_ip(al.map, ip) : (u64) 0);
-
- return ui->cb(&e, ui->arg);
+ return 0;
}
static pid_t next_thread(Dwfl *dwfl, void *arg, void **thread_argp)
@@ -168,7 +172,7 @@ int unwind__get_entries(unwind_entry_cb_t cb, void *arg,
struct perf_sample *data,
int max_stack)
{
- struct unwind_info ui = {
+ struct unwind_info *ui, ui_buf = {
.sample = data,
.thread = thread,
.machine = thread->mg->machine,
@@ -177,35 +181,54 @@ int unwind__get_entries(unwind_entry_cb_t cb, void *arg,
.max_stack = max_stack,
};
Dwarf_Word ip;
- int err = -EINVAL;
+ int err = -EINVAL, i;
if (!data->user_regs.regs)
return -EINVAL;
- ui.dwfl = dwfl_begin(&offline_callbacks);
- if (!ui.dwfl)
+ ui = zalloc(sizeof(ui_buf) + sizeof(ui_buf.entries[0]) * max_stack);
+ if (!ui)
+ return -ENOMEM;
+
+ *ui = ui_buf;
+
+ ui->dwfl = dwfl_begin(&offline_callbacks);
+ if (!ui->dwfl)
goto out;
err = perf_reg_value(&ip, &data->user_regs, PERF_REG_IP);
if (err)
goto out;
- err = report_module(ip, &ui);
+ err = report_module(ip, ui);
if (err)
goto out;
- if (!dwfl_attach_state(ui.dwfl, EM_NONE, thread->tid, &callbacks, &ui))
+ if (!dwfl_attach_state(ui->dwfl, EM_NONE, thread->tid, &callbacks, ui))
goto out;
- err = dwfl_getthread_frames(ui.dwfl, thread->tid, frame_callback, &ui);
+ err = dwfl_getthread_frames(ui->dwfl, thread->tid, frame_callback, ui);
- if (err && !ui.max_stack)
+ if (err && !ui->max_stack)
err = 0;
+ /*
+ * Display what we got based on the order setup.
+ */
+ for (i = 0; i < ui->idx && !err; i++) {
+ int j = i;
+
+ if (callchain_param.order == ORDER_CALLER)
+ j = ui->idx - i - 1;
+
+ err = ui->entries[j].ip ? ui->cb(&ui->entries[j], ui->arg) : 0;
+ }
+
out:
if (err)
pr_debug("unwind: failed with '%s'\n", dwfl_errmsg(-1));
- dwfl_end(ui.dwfl);
+ dwfl_end(ui->dwfl);
+ free(ui);
return 0;
}
diff --git a/tools/perf/util/unwind-libdw.h b/tools/perf/util/unwind-libdw.h
index 417a142..5832866 100644
--- a/tools/perf/util/unwind-libdw.h
+++ b/tools/perf/util/unwind-libdw.h
@@ -16,6 +16,8 @@ struct unwind_info {
unwind_entry_cb_t cb;
void *arg;
int max_stack;
+ int idx;
+ struct unwind_entry entries[];
};
#endif /* __PERF_UNWIND_LIBDW_H */
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