Re: [PATCH 25/28] perf top: Convert to hist_entry_iter

Namhyung Kim
2014-01-13T10:45:21Z

On Mon, 13 Jan 2014 17:55:46 +0900, Namhyung Kim wrote:
> On Sat, 11 Jan 2014 17:35:29 +0100, Jiri Olsa wrote:
>> On Wed, Jan 08, 2014 at 05:46:30PM +0900, Namhyung Kim wrote:
>>> Reuse hist_entry_iter__add() function to share the similar code with
>>> perf report. Note that it needs to be called with hists.lock so tweak
>>> some internal functions not to deadlock or hold the lock too long.
>>>
>>> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
>>> ---
>>> tools/perf/builtin-top.c | 75 ++++++++++++++++++++++++------------------------
>>> 1 file changed, 37 insertions(+), 38 deletions(-)
>>>
>>> diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
>>> index f0f55e6030cd..cf330c66bed7 100644
>>> --- a/tools/perf/builtin-top.c
>>> +++ b/tools/perf/builtin-top.c
>>> @@ -186,9 +186,6 @@ static void perf_top__record_precise_ip(struct perf_top *top,
>>> sym = he->ms.sym;
>>> notes = symbol__annotation(sym);
>>>
>>> - if (pthread_mutex_trylock(&notes->lock))
>>> - return;
>>> -
>>> ip = he->ms.map->map_ip(he->ms.map, ip);
>>> err = hist_entry__inc_addr_samples(he, counter, ip);
>>>
>>> @@ -201,6 +198,8 @@ static void perf_top__record_precise_ip(struct perf_top *top,
>>> sym->name);
>>> sleep(1);
>>> }
>>> +
>>> + pthread_mutex_lock(&notes->lock);
>>> }
>>
>> locking on function exit.. does not look right ;-)
>
> Yes, it looks weird.. but it's because of the change in locking. After
> I changed perf top to use the hist_entry_iter, it needed to protect
> the whole hist_entry_iter__add() by hists->lock so the
> perf_top__record_precise_ip() should be called with the lock acquired.

Argh, it was a different lock.. But it seems still need to dance
anyway. ;-)

Thanks,
Namhyung