On Wed, 28 Feb 2007 14:37:49 +0100 John <linux.kernel@xxxxxxx> wrote: > John wrote: > > > I know it's possible to have Linux timestamp incoming datagrams as soon > > as they are received, then for one to retrieve this timestamp later with > > an ioctl command or a recvmsg call. > > Has it ever been proposed to modify struct skb_timeval to hold > nanosecond stamps instead of just microsecond stamps? Then make the > improved precision somehow available to user space. > I am playing with a couple of possible future changes. 1. Change skb timestamp to be a timespec instead of timeval, for ABI compatiablity the existing SO_TIMESTAMP has to stay microseconds, but add a new SO_TIMESPEC to get the nanosecond version. The change gets non trivial because of other uses of timestamp (like vegas) so I gave up for now. 2. Use hardware receive timestamp in Yukon2 to put actual receive time into skb timestamp. Works, but still figuring out how to manage clock skew/resync. - To unsubscribe from this list: send the line "unsubscribe linux-net" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
