perf probe: Filter out redundant inline-instances
authorMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Thu, 11 Aug 2011 11:03:18 +0000 (20:03 +0900)
committerArnaldo Carvalho de Melo <acme@redhat.com>
Fri, 12 Aug 2011 12:34:35 +0000 (09:34 -0300)
commit3f4460a28fb2f73df6c32c3a305797abc01c0f9c
treeb3c6864c3da3d864471f74a5014800ac38f62dcd
parentdb0d2c6420eeb8fd669bac84d72f1ab828bbaa64
perf probe: Filter out redundant inline-instances

With gcc4.6, some instances of concrete inlined function looks redundant
and broken, because it appears inside of a concrete instance and its
call_file and call_line are same as the original abstruct's decl_file
and decl_line respectively.

e.g.
 [  d1aa]    subprogram
             external             (flag) Yes
             name                 (strp) "add_timer"
             decl_file            (data1) 2 ;here is original
             decl_line            (data2) 847 ;line and file
             prototyped           (flag) Yes
             inline               (data1) inlined (1)
             sibling              (ref4) [  d1c6]
...
 [ 11d84]    subprogram
             abstract_origin      (ref4) [  d1aa] ; concrete instance
             low_pc               (addr) .text+0x000000000000246f <add_timer>
             high_pc              (addr) .text+0x000000000000248b <mod_timer_pending>
             frame_base           (block1)               [   0] call_frame_cfa
             sibling              (ref4) [ 11dd9]
 [ 11d9f]      formal_parameter
               abstract_origin      (ref4) [  d1b9]
               location             (data4) location list [  701b]
 [ 11da8]      inlined_subroutine
               abstract_origin      (ref4) [  d1aa] ; redundant instance
               low_pc               (addr) .text+0x000000000000247e <add_timer+0xf>
               high_pc              (addr) .text+0x0000000000002480 <add_timer+0x11>
               call_file            (data1) 2 ; call line and file
               call_line            (data2) 847 ; are same as above

Those redundant instances leads unwilling results;

e.g. find probe points inside of functions even if we specify
a function entry as below;

$ perf probe -V add_timer
Available variables at add_timer
        @<add_timer+0>
                struct timer_list*      timer
        @<add_timer+15>
                (No matched variables)

So, this filters out those redundant instances based on call-site and
decl-site information.

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/20110811110317.19900.59525.stgit@fedora15
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
tools/perf/util/dwarf-aux.c