On 04/08/2013 10:58 AM, Pawel Moll wrote:
Now, before I spend time doing all this, a question to John, Peter, Stephane and the rest of the public - would a solution providing such userspace interface:fd = sys_perf_open() timestamp = clock_gettime((FD_TO_CLOCKID(fd), &ts) be acceptable to all?
So thinking this through further, I'm worried we may _not_ be able to eventually enable this to be a vdso as I had earlier hoped. Mostly because I'm not sure how the fd -> file -> clock lookup could be done in userland (any ideas?).
So this makes this approach mostly equivalent long term to the ioctl method, from a performance perspective. And makes the dynamic posix clockid somewhat less of a middle-ground compromise between the ioctl and generic constant clockid approach.
So while I'm not opposed to the sort of extention proposed above, I want to make sure introducing the new approach is worth the effort when compared with just adding an ioctl.
thanks -john -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
