forked from Minki/linux
9afcb420d6
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>
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| .. | ||
| arch | ||
| bench | ||
| config | ||
| Documentation | ||
| python | ||
| scripts | ||
| tests | ||
| trace/strace/groups | ||
| ui | ||
| util | ||
| .gitignore | ||
| Build | ||
| builtin-annotate.c | ||
| builtin-bench.c | ||
| builtin-buildid-cache.c | ||
| builtin-buildid-list.c | ||
| builtin-data.c | ||
| builtin-diff.c | ||
| builtin-evlist.c | ||
| builtin-help.c | ||
| builtin-inject.c | ||
| builtin-kmem.c | ||
| builtin-kvm.c | ||
| builtin-list.c | ||
| builtin-lock.c | ||
| builtin-mem.c | ||
| builtin-probe.c | ||
| builtin-record.c | ||
| builtin-report.c | ||
| builtin-sched.c | ||
| builtin-script.c | ||
| builtin-stat.c | ||
| builtin-timechart.c | ||
| builtin-top.c | ||
| builtin-trace.c | ||
| builtin.h | ||
| command-list.txt | ||
| CREDITS | ||
| design.txt | ||
| Makefile | ||
| Makefile.perf | ||
| MANIFEST | ||
| perf-archive.sh | ||
| perf-completion.sh | ||
| perf-read-vdso.c | ||
| perf-sys.h | ||
| perf-with-kcore.sh | ||
| perf.c | ||
| perf.h | ||