On Fri, Jul 16, 2010 at 12:36 PM, Jan Ceuleers <[email protected]> wrote: > On 15/07/10 18:42, Radhesh Kamath wrote: >> I have a kernel module that sends me an RDTSC value to userspace, and >> I need to get a UTC timestamp based on this. >> As far as I understand, RDTSC gives me the clock ticks that have >> elapsed since the processor was switched on (this is a 64-bit machine, >> so my guess is that wraparound is not an issue). >> >> How can I use this info to obtain a UTC timestamp? > > Radhesh, > > I suggest that you look into the NTP daemon (ntpd, http://www.ntp.org/). > > This daemon already does its best to obtain timing information from as > many sources as you configure, in order to discipline the local clock to > observe UTC as closely as possible. > > Jan
Hi Jan, Thanks for the suggestion about the NTP daemon. But the problem I am trying to solve is different. I need to get a UTC timestamp, and use the RDTSC for doing so. The CPU frequency is not varied, so a tick will represent the same amount of time. So the question is, how do I arrive at a UTC value? Thanks, Radhesh > > -- > To unsubscribe from this list: send an email with > "unsubscribe kernelnewbies" to [email protected] > Please read the FAQ at http://kernelnewbies.org/FAQ > > -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to [email protected] Please read the FAQ at http://kernelnewbies.org/FAQ
