linux-kernel - Re: [PATCH 25/28] perf top: Convert to hist_entry

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <877ga4b1oj.fsf@sejong.aot.lge.com>
Date:	Mon, 13 Jan 2014 19:45:16 +0900
From:	Namhyung Kim <namhyung@...nel.org>
To:	Jiri Olsa <jolsa@...hat.com>
Cc:	Arnaldo Carvalho de Melo <acme@...stprotocols.net>,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Paul Mackerras <paulus@...ba.org>,
	Ingo Molnar <mingo@...nel.org>,
	Namhyung Kim <namhyung.kim@....com>,
	LKML <linux-kernel@...r.kernel.org>,
	Arun Sharma <asharma@...com>,
	Frederic Weisbecker <fweisbec@...il.com>,
	Rodrigo Campos <rodrigo@...g.com.ar>
Subject: Re: [PATCH 25/28] perf top: Convert to hist_entry_iter

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@...nel.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
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/