Re: [RFC 2/2] perf: Marker software event and ioctl

[Pawel Moll <pawel.moll@arm.com>]

On Fri, 2014-09-12 at 14:49 +0100, Arnaldo Carvalho de Melo wrote:
> Perhaps both? I.e. an u64 followed from a string, if the u64 is zero,
> then there is a string right after it?

How would this look like in userspace? Something like this?

8<----
struct perf_event_marker {
	uint64_t value;
	char *string;
} arg;

arg.value = 0x1234;

/* or */

arg.value = 0;
arg.string = "abcd";

ioctl(fd, PERF_EVENT_IOC_MARKER, &arg)
8<----

If so, maybe it would simpler just to go for classic size/data
structure?

8<-----
struct perf_event_marker {
	uint32_t size;
	void *data;
}
8<-----

This would directly map into struct perf_raw_record...

Paweł