Re: [PATCH 1/2] perf_event_open.2: Document PERF_EVENT_IOC_PAUSE_OUTPUT

From: Michael Kerrisk (man-pages)
Date: Sat Oct 22 2016 - 06:00:25 EST


On 10/21/2016 11:16 PM, Vince Weaver wrote:
> On Fri, 21 Oct 2016, Wang Nan wrote:
>
>
>> -.SS Using prctl(2)
>> +.SS Using prctl
>
> why this change?

I suspect a diff against a slight stale version of the page,
since I added the '(2)' just a few days ago. Wang Nan, please
do pull the latest version of the page :-).

>> +.BR PERF_EVENT_IOC_PAUSE_OUTPUT " (since Linux 4.7)"
>> +.\" commit 86e7972f690c1017fd086cdfe53d8524e68c661c
>> +This allows pausing and resuming the event's ring-buffer. A
>> +paused ring-buffer does not prevent samples generation, but simply
>> +discards them. The discarded samples are considered lost, causes
>> +.BR PERF_RECORD_LOST
>> +to be generated when possible.
>
> I don't know if it's worth mentioning that the reason to add this is to
> allow reading the ring-buffer without having to worry about data being
> overwritten.

Wang Nan, what do you you thing. Should this be added?

> There are a few odd wording choices (mostly plural nouns) but otherwise
> looks fine to me.
>
> Reviewed-by: Vince Weaver <vincent.weaver@xxxxxxxxx>

Wang Nan, I'll send a few wording corrections. Could you please include
Vince's reviewed by tag on your next revision?

Thanks,

Michael


--
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/