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perf probe: Fix to search local variables in appropriate scope

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Fix perf probe to search local variables in appropriate local inlined
function scope. For example, pre_schedule() has only 2 local variables,
as below;

$ perf probe -L pre_schedule
<pre_schedule@/home/mhiramat/ksrc/linux-2.6/kernel/sched.c:0>
      0  static inline void pre_schedule(struct rq *rq, struct task_struct *prev)
         {
      2         if (prev->sched_class->pre_schedule)
      3                 prev->sched_class->pre_schedule(rq, prev);
         }

However, current perf probe shows 4 local variables on pre_schedule(),
because it searches variables in the caller(schedule()) scope.

$ perf probe -V pre_schedule
Available variables at pre_schedule
        @<schedule+445>
                int     cpu
                long unsigned int*      switch_count
                struct rq*      rq
                struct task_struct*     prev

This patch fixes this issue by searching variables in the local scope of
the instance of inlined function. Here is the result.

$ perf probe -V pre_schedule
Available variables at pre_schedule
        @<schedule+445>
                struct rq*      rq
                struct task_struct*     prev

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://lkml.kernel.org/r/20110811110259.19900.85664.stgit@fedora15
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Masami Hiramatsu
2011-08-11 20:02:59 +09:00
committed by Arnaldo Carvalho de Melo
parent 13e27d7686
commit 221d061182
4 changed files with 144 additions and 27 deletions
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33
tools/perf/util/dwarf-aux.c
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@@ -96,6 +96,39 @@ int cu_find_lineinfo(Dwarf_Die *cu_die, unsigned long addr,
return *lineno ?: -ENOENT;
}
static int __die_find_inline_cb(Dwarf_Die *die_mem, void *data);
/**
* cu_walk_functions_at - Walk on function DIEs at given address
* @cu_die: A CU DIE
* @addr: An address
* @callback: A callback which called with found DIEs
* @data: A user data
*
* Walk on function DIEs at given @addr in @cu_die. Passed DIEs
* should be subprogram or inlined-subroutines.
*/
int cu_walk_functions_at(Dwarf_Die *cu_die, Dwarf_Addr addr,
int (*callback)(Dwarf_Die *, void *), void *data)
{
Dwarf_Die die_mem;
Dwarf_Die *sc_die;
int ret = -ENOENT;
/* Inlined function could be recursive. Trace it until fail */
for (sc_die = die_find_realfunc(cu_die, addr, &die_mem);
sc_die != NULL;
sc_die = die_find_child(sc_die, __die_find_inline_cb, &addr,
&die_mem)) {
ret = callback(sc_die, data);
if (ret)
break;
}
return ret;
}
/**
* die_compare_name - Compare diename and tname
* @dw_die: a DIE