[tip:perf/core] perf probe: Enable to put probe inline function call site

tip-bot for Masami Hiramatsu
2011-01-26T07:23:16Z

Commit-ID: 5069ed86be3c2f28bcdf7fae1374ec0c325aafba
Gitweb: http://git.kernel.org/tip/5069ed86be3c2f28bcdf7fae1374ec0c325aafba
Author: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
AuthorDate: Thu, 13 Jan 2011 21:46:05 +0900
Committer: Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Mon, 24 Jan 2011 10:57:03 -0200

perf probe: Enable to put probe inline function call site

Enable to put probe inline function call site. This will increase line-based
probe-ability.

<Without this patch>
$ ./perf probe -L schedule:48
<schedule:48>
pre_schedule(rq, prev);

50 if (unlikely(!rq->nr_running))
idle_balance(cpu, rq);

put_prev_task(rq, prev);
next = pick_next_task(rq);

56 if (likely(prev != next)) {
sched_info_switch(prev, next);
trace_sched_switch_out(prev, next);
perf_event_task_sched_out(prev, next);

<With this patch>
$ ./perf probe -L schedule:48
<schedule:48>
48 pre_schedule(rq, prev);

50 if (unlikely(!rq->nr_running))
51 idle_balance(cpu, rq);

53 put_prev_task(rq, prev);
54 next = pick_next_task(rq);

56 if (likely(prev != next)) {
57 sched_info_switch(prev, next);
58 trace_sched_switch_out(prev, next);
59 perf_event_task_sched_out(prev, next);

Cc: 2nddept-manager@sdl.hitachi.co.jp
Cc: Franck Bui-Huu <fbuihuu@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20110113124604.22426.48873.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/util/probe-finder.c | 56 ++++++++++++++++++++++++++++++++++-----
1 files changed, 48 insertions(+), 8 deletions(-)

diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
index 508c017..69215bf 100644
--- a/tools/perf/util/probe-finder.c
+++ b/tools/perf/util/probe-finder.c
@@ -280,6 +280,19 @@ static bool die_compare_name(Dwarf_Die *dw_die, const char *tname)
return name ? (strcmp(tname, name) == 0) : false;
}

+/* Get callsite line number of inline-function instance */
+static int die_get_call_lineno(Dwarf_Die *in_die)
+{
+ Dwarf_Attribute attr;
+ Dwarf_Word ret;
+
+ if (!dwarf_attr(in_die, DW_AT_call_line, &attr))
+ return -ENOENT;
+
+ dwarf_formudata(&attr, &ret);
+ return (int)ret;
+}
+
/* Get type die */
static Dwarf_Die *die_get_type(Dwarf_Die *vr_die, Dwarf_Die *die_mem)
{
@@ -463,27 +476,54 @@ typedef int (* line_walk_handler_t) (const char *fname, int lineno,
Dwarf_Addr addr, void *data);

struct __line_walk_param {
+ const char *fname;
line_walk_handler_t handler;
void *data;
int retval;
};

-/* Walk on decl lines in given DIE */
+static int __die_walk_funclines_cb(Dwarf_Die *in_die, void *data)
+{
+ struct __line_walk_param *lw = data;
+ Dwarf_Addr addr;
+ int lineno;
+
+ if (dwarf_tag(in_die) == DW_TAG_inlined_subroutine) {
+ lineno = die_get_call_lineno(in_die);
+ if (lineno > 0 && dwarf_entrypc(in_die, &addr) == 0) {
+ lw->retval = lw->handler(lw->fname, lineno, addr,
+ lw->data);
+ if (lw->retval != 0)
+ return DIE_FIND_CB_FOUND;
+ }
+ }
+ return DIE_FIND_CB_SIBLING;
+}
+
+/* Walk on lines of blocks included in given DIE */
static int __die_walk_funclines(Dwarf_Die *sp_die,
line_walk_handler_t handler, void *data)
{
- const char *fname;
+ struct __line_walk_param lw = {
+ .handler = handler,
+ .data = data,
+ .retval = 0,
+ };
+ Dwarf_Die die_mem;
Dwarf_Addr addr;
- int lineno, ret = 0;
+ int lineno;

/* Handle function declaration line */
- fname = dwarf_decl_file(sp_die);
- if (fname && dwarf_decl_line(sp_die, &lineno) == 0 &&
+ lw.fname = dwarf_decl_file(sp_die);
+ if (lw.fname && dwarf_decl_line(sp_die, &lineno) == 0 &&
dwarf_entrypc(sp_die, &addr) == 0) {
- ret = handler(fname, lineno, addr, data);
+ lw.retval = handler(lw.fname, lineno, addr, data);
+ if (lw.retval != 0)
+ goto done;
}
-
- return ret;
+ die_find_child(sp_die, __die_walk_funclines_cb, &lw, &die_mem);
+done:
+ return lw.retval;
}

static int __die_walk_culines_cb(Dwarf_Die *sp_die, void *data)