On Thu, 11 Aug 2016, Mathieu Poirier wrote: > +.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. So I gave up and read the code and I'm guessing this is what you really mean: .TP .BR PERF_EVENT_IOC_SET_DRV_CONFIGS " (since Linux 4.9)" Pass custom configuration paramaters to a PMU driver. The argument is a pointer to a NUL-termiated string of up to PAGE_SIZE in length. The string contains a list of comma-separated configuration options that will be parsed by the kernel. The kernel handles both singleton values as well as name/value pairs that are indicated with the '=' character. The size of the strings is limited internally to PERF_DRV_CONFIG_MAX (which is not visible to userspace). some additional questions: can this ioctl be run at any time or should it only be run while the event is quiet? Does the change in options take place immediately? Vince -- 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
