Commit Graph

3 Commits

Author SHA1 Message Date
Masami Hiramatsu b0e9cb2802 perf probe: Fix to search nested inlined functions in CU
Fix perf probe to walk through the lines of all nested inlined function
call sites and declared lines when a whole CU is passed to the line
walker.

The die_walk_lines() can have two different type of DIEs, subprogram (or
inlined-subroutine) DIE and CU DIE.

If a caller passes a subprogram DIE, this means that the walker walk on
lines of given subprogram. In this case, it just needs to search on
direct children of DIE tree for finding call-site information of inlined
function which directly called from given subprogram.

On the other hand, if a caller passes a CU DIE to the walker, this means
that the walker have to walk on all lines in the source files included
in given CU DIE. In this case, it has to search whole DIE trees of all
subprograms to find the call-site information of all nested inlined
functions.

Without this patch:

$ perf probe --line kernel/cpu.c:151-157
</home/mhiramat/ksrc/linux-2.6/kernel/cpu.c:151>

         static int cpu_notify(unsigned long val, void *v)
         {
    154         return __cpu_notify(val, v, -1, NULL);
         }

With this:
$ perf probe --line kernel/cpu.c:151-157
</home/mhiramat/ksrc/linux-2.6/kernel/cpu.c:151>

    152  static int cpu_notify(unsigned long val, void *v)
         {
    154         return __cpu_notify(val, v, -1, NULL);
         }

As you can see, --line option with source line range shows the declared
lines as probe-able.

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/20110811110241.19900.34994.stgit@fedora15
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2011-08-12 09:23:39 -03:00
Masami Hiramatsu a128405c6b perf probe: Fix line walker to check CU correctly
Fix line walker to check whether a given DIE is CU or not.

Actually this function accepts CU, subprogram and inlined_subroutine
DIEs.

Without this fix, perf probe always fails to analyze lines on inlined
functions;

$ perf probe -L pre_schedule
Debuginfo analysis failed. (-2)
  Error: Failed to show lines. (-2)

This fixes that bug, 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);
         }

         /* rq->lock is NOT held, but preemption is disabled */

Changes from v1:
 - Update against current tip tree.(Fix dwarf-aux.c)

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <masami.hiramatsu@gmail.com>
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/20110811110235.19900.20614.stgit@fedora15
Signed-off-by: Masami Hiramatsu <masami.hiramatsu@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2011-08-12 09:22:46 -03:00
Masami Hiramatsu e0d153c690 perf-probe: Move dwarf library routines to dwarf-aux.{c, h}
Move dwarf library related routines to dwarf-aux.{c,h}.
This includes several minor changes.
- Add simple documents for each API.
- Rename die_find_real_subprogram() to die_find_realfunc()
- Rename line_walk_handler_t to line_walk_callback_t.
- Minor cleanups.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Link: http://lkml.kernel.org/r/20110627072727.6528.57647.stgit@fedora15
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-07-15 16:10:17 -04:00