Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
IronPort-SDR: irxi7yCc99vDTKUOxMIOBvcxH5VN+uHdJ/6qcaqutJ4WJT9grQSRAnLe3J2C/KSgcrUdR/Xmgc
 sYpcQwpvhj3w==
IronPort-SDR: n508GLROkb2f5DO81n+WQ12yzA4hWL7jUjsBE+j0nm+38Qi1Tw3YeolIXKfQ93rzfF+3cLegSg
 KOLpfzZnrnuA==
Subject: Re: [PATCH v4 10/10] perf record: introduce --ctl-fd[-ack] options
To:     Adrian Hunter <adrian.hunter@intel.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>
Cc:     Jiri Olsa <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Andi Kleen <ak@linux.intel.com>,
        linux-kernel <linux-kernel@vger.kernel.org>
References: <653fe5f3-c986-a841-1ed8-0a7d2fa24c00@linux.intel.com>
 <cd791bc8-2609-a136-a833-1dab6df68ff2@linux.intel.com>
 <b4b2ddb9-296b-c260-32ef-fee17e04a29d@intel.com>
From:   Alexey Budankov <alexey.budankov@linux.intel.com>
Organization: Intel Corp.
Message-ID: <17506256-ef3d-e3a2-a655-a9059b652785@linux.intel.com>
Date:   Wed, 3 Jun 2020 15:52:35 +0300
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101
 Thunderbird/68.8.1
MIME-Version: 1.0
In-Reply-To: <b4b2ddb9-296b-c260-32ef-fee17e04a29d@intel.com>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk


On 03.06.2020 15:05, Adrian Hunter wrote:
> On 25/05/20 5:23 pm, Alexey Budankov wrote:
>>
>> Introduce --ctl-fd[-ack] options to pass open file descriptors numbers
>> from command line. Extend perf-record.txt file with --ctl-fd[-ack]
>> options description. Document possible usage model introduced by
>> --ctl-fd[-ack] options by providing example bash shell script.
>>
>> Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
>> ---
>>  tools/perf/Documentation/perf-record.txt | 39 ++++++++++++++++++++++++
>>  tools/perf/builtin-record.c              | 10 ++++++
>>  tools/perf/util/record.h                 |  2 ++
>>  3 files changed, 51 insertions(+)
>>
>> diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
>> index c2c4ce7ccee2..5c012cfe68a4 100644
>> --- a/tools/perf/Documentation/perf-record.txt
>> +++ b/tools/perf/Documentation/perf-record.txt
>> @@ -614,6 +614,45 @@ appended unit character - B/K/M/G
>>  	The number of threads to run when synthesizing events for existing processes.
>>  	By default, the number of threads equals 1.
>>  
>> +--ctl-fd::
>> +--ctl-fd-ack::
>> +Listen on ctl-fd descriptor for command to control measurement ('enable': enable events,
>> +'disable': disable events. Optionally send control command completion ('ack') to fd-ack
>> +descriptor to synchronize with the controlling process. 
> 
> You should also explain the use of --delay=-1 here.

Well, possibly like this:

"Listen on ctl-fd descriptor for command to control measurement ('enable': enable events,
 'disable': disable events). Measurements can be started paused using --delay=-1 option.
 Optionally send control command completion ('ack') to fd-ack descriptor to synchronize
 with the controlling process. Example of bash shell script to enable and disable events
 during measurements:"