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

From: Jiri Olsa
Date: Fri Jun 05 2020 - 06:51:20 EST


On Tue, Jun 02, 2020 at 04:43:58PM +0300, Adrian Hunter wrote:
> 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.

the single option Adrian suggested seems better to me:

--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

we already support this kind of options arguments, like for --call-graph

jirka