Messages in this thread | | | Subject | Re: [PATCH v5 13/13] perf record: introduce --ctl-fd[-ack] options | From | Alexey Budankov <> | Date | Fri, 5 Jun 2020 18:23:17 +0300 |
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On 05.06.2020 17:47, Alexey Budankov wrote: > > On 05.06.2020 16:57, Jiri Olsa wrote: >> On Fri, Jun 05, 2020 at 04:15:52PM +0300, Alexey Budankov wrote: >>> >>> On 05.06.2020 13:51, Jiri Olsa wrote: >>>> 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 >>> >>> What if a user specifies fifos named like this above, not fds? >>> >>>> --control 11,15,disabled >>>> --control 11,,disabled >>>> --control /tmp/my-perf.fifo >>>> --control /tmp/my-perf.fifo,/tmp/my-perf-ack.fifo >>> >>> What if a user wants not fifos but other type of comm channels? >>> >>>> --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 >>>> >>> >>> IMHO, >>> this interface, of course, looks more compact (in amount of options) however >>> the other side it is less user friendly. One simple option for one simple >>> purpose is more convenient as for users as for developers. Also complex >>> option syntax tends to have limitations and there are probably more >>> non-obvious ones. >>> >>> Please speak up. I might have missed something meaningful. >> >> how about specify the type like: >> >> --control fd:1,2,... > > What do these ... mean?
After all, if you want it this way and it now also fits my needs I could convert --ctl-fd[-ack] to --control fd:<ctl-fd>,<ack-fd> with use cases like --control fd:<ctl-fd> and --control fd:<ctl-fd>,<ack-fd>. Accepted?
~Alexey
> >> --control fifo:/tmp/fifo1,/tmp/fifo2 >> --control xxx:.... >> >> this way we can extend the functionality in the future >> and stay backward compatible, while keeping single option > > Well, it clarifies more. However it still implicitly assumes > and requires proper ordering e.g. 1 is ctl-fd and 2 is ack-fd > and if there are some more positions there will be gaps like > --control fd:10,,something,,something ... > > Why is one single option with complex syntax more preferable > than several simple options? Also it would still consume almost > equal amount of command line space in shell. > > Thanks, > Alexey > >> >> jirka >>
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