We were dropping the reference we possibly held but not obtaining one
for the new maps, which we will drop at perf_evlist__delete(), fix it.
This was caught by Steven Noonan in some of the machines which would
produce this output when caught by glibc debug mechanisms:
$ sudo perf test 21
21: Test object code reading :***
Error in `perf': corrupted double-linked list: 0x00000000023ffcd0 ***
======= Backtrace: =========
/usr/lib/libc.so.6(+0x72055)[0x7f25be0f3055]
/usr/lib/libc.so.6(+0x779b6)[0x7f25be0f89b6]
/usr/lib/libc.so.6(+0x7a0ed)[0x7f25be0fb0ed]
/usr/lib/libc.so.6(__libc_calloc+0xba)[0x7f25be0fceda]
perf(parse_events_lex_init_extra+0x38)[0x4cfff8]
perf(parse_events+0x55)[0x4a0615]
perf(perf_evlist__config+0xcf)[0x4eeb2f]
perf[0x479f82]
perf(test__code_reading+0x1e)[0x47ad4e]
perf(cmd_test+0x5dd)[0x46452d]
perf[0x47f4e3]
perf(main+0x603)[0x42c723]
/usr/lib/libc.so.6(__libc_start_main+0xf0)[0x7f25be0a1610]
perf(_start+0x29)[0x42c859]
Further investigation using valgrind led to the reference count imbalance fixed
in this patch.
Reported-and-Tested-by: Steven Noonan <steven@uplinklabs.net>
Report-Link: http://lkml.kernel.org/r/CAKbGBLjC2Dx5vshxyGmQkcD+VwiAQLbHoXA9i7kvRB2-2opHZQ@mail.gmail.com
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Fixes: f30a79b012 ("perf tools: Add reference counting for cpu_map object")
Link: http://lkml.kernel.org/n/tip-j0u1bdhr47sa511sgg76kb8h@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
a55e566376