Re: [PATCH v5 13/13] perf record: introduce --ctl-fd[-ack] options

Adrian Hunter
2020-06-02T13:44:35Z

On 2/06/20 12:12 pm, Alexey Budankov wrote:
>
> On 02.06.2020 11:32, Alexey Budankov wrote:
>>
>> On 02.06.2020 2:37, Andi Kleen wrote:
>>>>> or a pathname, or including also the event default of "disabled".
>>>>
>>>> For my cases conversion of pathnames into open fds belongs to external
>>>> controlling process e.g. like in the examples provided in the patch set.
>>>> Not sure about "event default of 'disabled'"
>>>
>>> It would be nicer for manual use cases if perf supported the path names
>>> directly like in Adrian's example, not needing a complex wrapper script.
>>
>> fds interface is required for VTune integration since VTune wants control
>> over files creation aside of Perf tool process. The script demonstrates
>> just one possible use case.
>>
>> Control files could easily be implemented on top of fds making open operations
>> for paths and then initializing fds. Interface below is vague and with explicit
>> options like below it could be more explicit:
>> --ctl-file /tmp/my-perf.fifo --ctl-file-ack /tmp/my-perf-ack.fifo
>
> Or even clearer:
>
> --ctl-fifo /tmp/my-perf --ctl-fifo-ack /tmp/my-perf-ack

If people are OK with having so many options, then that is fine by me.

>
>>
>> Make either fds and or files provided on the command line. Implement file
>> options handling callbacks that would open paths and setting fds. Close fds
>> if they were opened by Perf tool process.
>>
>> Adrian, please share your mind and use case.
>>
>> ~Alexey
>>
>>>
>>> -Andi
>>>>
>>>>>
>>>>> e.g. add "--control" and support all of:
>>>>>
>>>>> --control
>>>>> --control 11
>>>>> --control 11,15
>>>>> --control 11,15,disabled
>>>>> --control 11,,disabled
>>>>> --control /tmp/my-perf.fifo
>>>>> --control /tmp/my-perf.fifo,/tmp/my-perf-ack.fifo
>>>>> --control /tmp/my-perf.fifo,/tmp/my-perf-ack.fifo,disabled
>>>>> --control /tmp/my-perf.fifo,,disabled
>>>>>
>>>>> Regards
>>>>> Adrian
>>>>>
>>>>
>>>> Regards,
>>>> Alexey
>>>>