lkml.org 
[lkml]   [2015]   [Nov]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[tip:perf/core] perf machine: Fix machine__findnew_module_map to put registered map
Commit-ID:  9afcb420d6cfeadf5d872f395061c611536615fb
Gitweb: http://git.kernel.org/tip/9afcb420d6cfeadf5d872f395061c611536615fb
Author: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
AuthorDate: Wed, 18 Nov 2015 15:40:20 +0900
Committer: Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Thu, 19 Nov 2015 13:19:18 -0300

perf machine: Fix machine__findnew_module_map to put registered map

Fix machine object to drop the reference to the map object after it
inserted it into machine->kmaps.

refcnt debugger shows what happened:
----
==== [2] ====
Unreclaimed map: 0x346f750
Refcount +1 => 1 at
./perf(map__new2+0xb5) [0x4bdea5]
./perf() [0x4b8aaf]
./perf(modules__parse+0xfc) [0x4a9cbc]
./perf() [0x4b83c0]
./perf(machine__create_kernel_maps+0x148) [0x4bb208]
./perf(machine__new_host+0xfa) [0x4bb3fa]
./perf(init_probe_symbol_maps+0x93) [0x5062b3]
./perf() [0x455ffa]
./perf(cmd_probe+0x6c) [0x4566bc]
./perf() [0x47abc5]
./perf(main+0x610) [0x421f90]
/lib64/libc.so.6(__libc_start_main+0xf5) [0x7f5373899af5]
./perf() [0x4220a9]
Refcount +1 => 2 at
./perf(maps__insert+0x9a) [0x4bfd4a]
./perf() [0x4b8acb]
./perf(modules__parse+0xfc) [0x4a9cbc]
./perf() [0x4b83c0]
./perf(machine__create_kernel_maps+0x148) [0x4bb208]
./perf(machine__new_host+0xfa) [0x4bb3fa]
./perf(init_probe_symbol_maps+0x93) [0x5062b3]
./perf() [0x455ffa]
./perf(cmd_probe+0x6c) [0x4566bc]
./perf() [0x47abc5]
./perf(main+0x610) [0x421f90]
/lib64/libc.so.6(__libc_start_main+0xf5) [0x7f5373899af5]
./perf() [0x4220a9]
Refcount -1 => 1 at
./perf(map_groups__exit+0x94) [0x4bea54]
./perf(machine__delete+0x3d) [0x4b91ed]
./perf(exit_probe_symbol_maps+0x28) [0x506358]
./perf() [0x45628a]
./perf(cmd_probe+0x6c) [0x4566bc]
./perf() [0x47abc5]
./perf(main+0x610) [0x421f90]
/lib64/libc.so.6(__libc_start_main+0xf5) [0x7f5373899af5]
./perf() [0x4220a9]
----

This pattern clearly shows that the refcnt of the map is acquired twice
by map__new2 and maps__insert but released onlu once at
map_groups__exit, when we purge its maps rbtree.

Since maps__insert already reference counted the map, we have to drop
the constructor (map__new2) reference count right after inserting it.

These happened in machine__findnew_module_map, as below.

----
# eu-addr2line -e ./perf -f 0x4b8aaf
machine__findnew_module_map inlined at util/machine.c:1046
in machine__create_module
util/machine.c:582
# eu-addr2line -e ./perf -f 0x4b8acb
map_groups__insert inlined at util/machine.c:585
in machine__create_module
util/map.h:208
----

(note that both are at util/machine.c:58X which is
machine__findnew_module_map)

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20151118064020.30709.40499.stgit@localhost.localdomain
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/util/machine.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 8b303ff..0487d77 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -585,6 +585,8 @@ struct map *machine__findnew_module_map(struct machine *machine, u64 start,

map_groups__insert(&machine->kmaps, map);

+ /* Put the map here because map_groups__insert alread got it */
+ map__put(map);
out:
free(m.name);
return map;

\
 
 \ /
  Last update: 2015-11-23 17:41    [W:0.188 / U:0.128 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site