On Fri, Jun 05, 2020 at 05:47:28PM +0300, 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?
other possible options > > > --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 ... right, that's what we do for other options > > 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. I think it's better for future.. say if there's going to be support for passing file paths you'll need to add something like --ctl-fifo and --ctl-fifo-ack no? with single option we'd just add something like: --control fifo:/tmp/my-perf.fifo,/tmp/my-perf-ack.fifo jirka
