From: Adrian Hunter <adrian.hunter@intel.com>
To: Jiri Olsa <jolsa@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>,
linux-kernel@vger.kernel.org,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Corey Ashford <cjashfor@linux.vnet.ibm.com>,
David Ahern <dsahern@gmail.com>,
Frederic Weisbecker <fweisbec@gmail.com>,
Ingo Molnar <mingo@kernel.org>,
Jean Pihet <jean.pihet@linaro.org>,
Namhyung Kim <namhyung@kernel.org>,
Paul Mackerras <paulus@samba.org>,
Peter Zijlstra <a.p.zijlstra@chello.nl>
Subject: Re: [PATCHv3 00/19] perf tools: Factor ordered samples queue
Date: Mon, 21 Jul 2014 15:09:07 +0300 [thread overview]
Message-ID: <53CD02E3.6090509@intel.com> (raw)
In-Reply-To: <20140721095415.GB8865@krava.redhat.com>
On 07/21/2014 12:54 PM, Jiri Olsa wrote:
> On Mon, Jul 21, 2014 at 11:47:35AM +0300, Adrian Hunter wrote:
>
> SNIP
>
>>>>> If PERF_RECORD_FINISHED_ROUND is missing the queue will
>>>>
>>>> Why is it missing?
>>>
>>> it's stored only for tracepoints now patch 17 fixies that
>>
>> Wouldn't that make a huge difference all by itself?
>>
>> I would make that the first patch, and measure the difference
>> that it makes by itself.
>
> yes, that makes the difference.. still I think it's good to control
> perf memory allocation and do not let it take gigabytes just because
> this event is missing
>
>>>> How do you know the results are still valid? Wouldn't it
>>>> be better to wait that extra 15% and know that the data has
>>>> been processed correctly?
>>>
>>> The HALF flush could cause the out of order message
>>> (which I get occasionaly anyway). Patch 19 allows
>>
>> Occasional out-of-order messages would be worth investigating
>> IMHO. Either there is a bug or there is some "interesting"
>> data being recorded.
>
> I've got it via 'perf timechart record -I' sometimes:
>
> [jolsa@ibm-x3650m4-01 perf]$ sudo ./perf timechart record -I
> ^C[ perf record: Woken up 337 times to write data ]
> [ perf record: Captured and wrote 290.256 MB perf.data (~12681486 samples) ]
> Warning:
> Processed 3365931 events and lost 1 chunks!
>
> Check IO/CPU overload!
>
> [jolsa@ibm-x3650m4-01 perf]$ sudo ./perf report --stdio
> Timestamp below last timeslice flush
> 0x2276f58 [0x68]: failed to process type: 9
> # To display the perf.data header info, please use --header/--header-only options.
> #
>
> I think the reaon might be that one of the CPU mmap buffer
> is behind and got data after the round finishes for its
> timestamp.. but I haven't checked deeply on this yet
>
>>
>>> out of order events after HALF flush.
>>>
>>> The main reason for me was to control the memory allocation,
>>> which could get enormous without ROUND events being stored.
>>
>> But now you are storing them...
>>
>>> The 100MB queue limit seems to be enough not to hit out of
>>> order event due to the HALF flush.
>>
>> ...so is the 100MB limit needed at all if you have ROUND
>> events?
>
> for data files captured without the ROUND events fix
I am not sure it should be the default then, if it is
not needed going forward.
next prev parent reply other threads:[~2014-07-21 12:10 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-20 21:55 Jiri Olsa
2014-07-20 21:55 ` [PATCH 01/19] perf tools: Fix accounting of " Jiri Olsa
2014-07-28 8:27 ` [tip:perf/core] perf session: " tip-bot for Jiri Olsa
2014-07-20 21:55 ` [PATCH 02/19] perf tools: Rename ordered_samples bool to ordered_events Jiri Olsa
2014-07-20 21:55 ` [PATCH 03/19] perf tools: Rename ordered_samples struct " Jiri Olsa
2014-07-20 21:55 ` [PATCH 04/19] perf tools: Rename ordered_events members Jiri Olsa
2014-07-20 21:55 ` [PATCH 05/19] perf tools: Add ordered_events_(new|delete) interface Jiri Olsa
2014-07-20 21:55 ` [PATCH 06/19] perf tools: Factor ordered_events_flush to be more generic Jiri Olsa
2014-07-20 21:55 ` [PATCH 07/19] perf tools: Limit ordered events queue size Jiri Olsa
2014-07-20 21:55 ` [PATCH 08/19] perf tools: Flush ordered events in case of allocation failure Jiri Olsa
2014-07-20 21:55 ` [PATCH 09/19] perf tools: Make perf_session_deliver_event global Jiri Olsa
2014-07-20 21:55 ` [PATCH 10/19] perf tools: Create ordered-events object Jiri Olsa
2014-07-20 21:55 ` [PATCH 11/19] perf tools: Use list_move in ordered_events_delete function Jiri Olsa
2014-07-20 21:55 ` [PATCH 12/19] perf tools: Add ordered_events_init function Jiri Olsa
2014-07-20 21:55 ` [PATCH 13/19] perf tools: Add ordered_events_free function Jiri Olsa
2014-07-20 21:55 ` [PATCH 14/19] perf tools: Add perf_config_u64 function Jiri Olsa
2014-07-20 21:55 ` [PATCH 15/19] perf tools: Add report.queue-size config file option Jiri Olsa
2014-07-20 21:56 ` [PATCH 16/19] perf tools: Add debug prints for ordered events queue Jiri Olsa
2014-07-20 21:56 ` [PATCH 17/19] perf tools: Always force PERF_RECORD_FINISHED_ROUND event Jiri Olsa
2014-07-24 21:34 ` Arnaldo Carvalho de Melo
2014-07-25 11:34 ` Jiri Olsa
2014-07-25 14:14 ` Arnaldo Carvalho de Melo
2014-07-25 15:45 ` Frederic Weisbecker
2014-07-25 16:12 ` Peter Zijlstra
2014-07-20 21:56 ` [PATCH 18/19] perf tools: Limit the ordered events queue by default to 100MB Jiri Olsa
2014-07-20 21:56 ` [PATCH 19/19] perf tools: Allow out of order messages in forced flush Jiri Olsa
2014-07-21 6:43 ` [PATCHv3 00/19] perf tools: Factor ordered samples queue Adrian Hunter
2014-07-21 8:02 ` Jiri Olsa
2014-07-21 8:47 ` Adrian Hunter
2014-07-21 9:54 ` Jiri Olsa
2014-07-21 12:09 ` Adrian Hunter [this message]
2014-07-21 12:35 ` Jiri Olsa
2014-07-21 12:58 ` Adrian Hunter
2014-07-21 16:31 ` Andi Kleen
2014-07-21 18:23 ` Adrian Hunter
2014-07-21 18:36 ` David Ahern
2014-07-21 18:44 ` Adrian Hunter
2014-07-24 14:19 ` Arnaldo Carvalho de Melo
2014-07-24 14:56 ` Jiri Olsa
2014-07-24 15:10 ` Arnaldo Carvalho de Melo
2014-07-24 15:20 ` Jiri Olsa
2014-07-24 15:51 ` David Ahern
2014-07-24 18:01 ` Adrian Hunter
2014-07-21 19:39 ` Andi Kleen
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