On 21 October 2016 at 00:50, Michael Kerrisk (man-pages) <mtk.manpages@xxxxxxxxx> wrote: > Hi Mathieu, > > This feature seems not to have made it into 4.9. (Or did I > miss something?) Is it still planned for a future release? Good morning Michael, We have decided to proceed differently and as such, it is no longer required. Thanks for the follow-up, Mathieu > > Cheers, > > Michael > > On 08/12/2016 07:56 PM, Mathieu Poirier wrote: >> On 12 August 2016 at 10:52, Vince Weaver <vince@xxxxxxxxxx> wrote: >>> On Thu, 11 Aug 2016, Mathieu Poirier wrote: >>> >>>> This manpage patch relates to the addition of the >>>> PERF_EVENT_IOC_SET_DRV_CONFIGS ioctl. >>>> >>>> link: http://www.spinics.net/lists/kernel/msg2318998.html >>>> Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx> >>>> --- >>>> man2/perf_event_open.2 | 6 ++++++ >>>> 1 file changed, 6 insertions(+) >>>> >>>> diff --git a/man2/perf_event_open.2 b/man2/perf_event_open.2 >>>> index 3c894ccd1209..315b6a91079a 100644 >>>> --- a/man2/perf_event_open.2 >>>> +++ b/man2/perf_event_open.2 >>>> @@ -2732,6 +2732,12 @@ The argument is a BPF program file descriptor that was created by >>>> a previous >>>> .BR bpf (2) >>>> system call. >>>> +.TP >>>> +.BR PERF_EVENT_IOC_SET_DRV_CONFIGS " (since Linux 4.9)" >>>> +This makes it possible to pass configuration parameters to PMU drivers. >>>> +Configuration parameters are specific to each drivers. >>>> + >>>> +The argument is a pointer to the desired configuration parameters. >>>> .SS Using prctl >>>> A process can enable or disable all the event groups that are >>>> attached to it using the >>> >>> This is a bit... vague. So we're adding an interface to allow passing >>> arbitrary binary blobs through the perf_event interface? >>> >>> Is there any structure at all to these blobs? From the other commit >>> messages it looked like you'd be passing in some sort of string. >> >> I am adding an interface to pass PMU specific configuration to the >> driver. Since PMU drivers exist for different architecture and >> drivers I am making the mechanism as generic as possible. >> >> In this case the CoreSight Tracers need to know what "sink" to use for >> a trace session. I've enhanced the perf cmd line tool to accept: >> >> perf -e cs_etm/@sink=some_sink_definition/ .... >> >> Everything falling with the '/' that is preceded by a '@' character is >> considered PMU driver material. At this time the perf lexer accept >> two format: >> >> "@cfg" and "@cfg=option". The lexer will strip off the '@' and pass >> "cfg" and "cfg=option" to the kernel. >> >> What gets sent down to the kernel is driver specific - it is up to the >> PMU drivers to parse and validate what's given to them. >> >> This feature loosely mimics the filter enhancement where it is now >> possible to specify: >> >> perf record -e some_event// --filter 'start 0xstart_addr,stop 0xstop_address' or >> perf record -e some_event// --filter 'filter 0xstart_address/offset' >> >> Here it is up to the event to supply the mechanic to deal with the >> filter specification (I'm doing the same thing). Keywords "start", >> "stop" and "filter" are common to both IntelPT and CoreSight tracers, >> making them ideal candidates for parsing in the core. >> >> But for driver specific configuration "sink" is only applicable to >> CoreSight tracers... >> >> Writing these lines I realise that "start", "stop" and "filter" are >> applicable to only two drivers (IntelPT and CoreSight). Peter, do you >> think I should look for "sink" in the core parser, just like it is >> done for filters? >> >> Guidance would be appreciated here. >> >> Mathieu >> >>> >>> Vince >> > > > -- > Michael Kerrisk > Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ > Linux/UNIX System Programming Training: http://man7.org/training/ -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
