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author | Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> | 2011-08-11 20:03:18 +0900 |
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committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2011-08-12 09:34:35 -0300 |
commit | 3f4460a28fb2f73df6c32c3a305797abc01c0f9c (patch) | |
tree | b3c6864c3da3d864471f74a5014800ac38f62dcd /tools | |
parent | db0d2c6420eeb8fd669bac84d72f1ab828bbaa64 (diff) | |
download | linux-3f4460a28fb2f73df6c32c3a305797abc01c0f9c.tar.bz2 |
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>
Diffstat (limited to 'tools')
-rw-r--r-- | tools/perf/util/dwarf-aux.c | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/tools/perf/util/dwarf-aux.c b/tools/perf/util/dwarf-aux.c index d0f4048b634f..ee51e9b4dc09 100644 --- a/tools/perf/util/dwarf-aux.c +++ b/tools/perf/util/dwarf-aux.c @@ -307,6 +307,17 @@ static int die_get_call_fileno(Dwarf_Die *in_die) return -ENOENT; } +/* Get the declared file index number in CU DIE */ +static int die_get_decl_fileno(Dwarf_Die *pdie) +{ + Dwarf_Sword idx; + + if (die_get_attr_sdata(pdie, DW_AT_decl_file, &idx) == 0) + return (int)idx; + else + return -ENOENT; +} + /** * die_get_call_file - Get callsite file name of inlined function instance * @in_die: a DIE of an inlined function instance @@ -467,6 +478,7 @@ static int __die_walk_instances_cb(Dwarf_Die *inst, void *data) Dwarf_Die origin_mem; Dwarf_Attribute *attr; Dwarf_Die *origin; + int tmp; attr = dwarf_attr(inst, DW_AT_abstract_origin, &attr_mem); if (attr == NULL) @@ -476,6 +488,16 @@ static int __die_walk_instances_cb(Dwarf_Die *inst, void *data) if (origin == NULL || origin->addr != iwp->addr) return DIE_FIND_CB_CONTINUE; + /* Ignore redundant instances */ + if (dwarf_tag(inst) == DW_TAG_inlined_subroutine) { + dwarf_decl_line(origin, &tmp); + if (die_get_call_lineno(inst) == tmp) { + tmp = die_get_decl_fileno(origin); + if (die_get_call_fileno(inst) == tmp) + return DIE_FIND_CB_CONTINUE; + } + } + iwp->retval = iwp->callback(inst, iwp->data); return (iwp->retval) ? DIE_FIND_CB_END : DIE_FIND_CB_CONTINUE; |