On Mon, 2004-12-13 at 19:59 +0530, Micheal Mukherji wrote: > Hello, > Kindly excuse me for posting this on debian thread...I dont know > whether it is apt or not, but as I am using Debian, I am posting > this.. > > Can somebody tell me how I can get time elapsed in nanoseconds > (possibly a function)? > I have looked at the date command, but it is getting overflown with in > a couple of seconds, so on a second probe I dont know how many times > it has overflown... > > I also googled for it, but all it was showing was links to RTLinux pages. > > Having got dismayed, I am posting on this list. > > If somebody knows, please let me too. > > Thanks in anticipation.
Not even the VAX and Alpha (which use a signed 64 bit timer, with an epoch of 17-Nov-1858 00:00:00.000, does nanosecond. It's timer is 100ns ticks. Maybe when the Linux timer uses 64 bits, then we'll get nanosecond resolution. Remember, though, that a ns is 1 billionth of a second, and so a 3GHz CPU will onll does 3 cycles in a ns. Unless you are coding to the bare metal with a *minimal* OS, like DOS, you can't do anything useful in 3 clock ticks. After all, memory access takes, what, 60ns? You'll probably need really specialized hardware. An atomic clock comes first to mind. -- ----------------------------------------------------------------- Ron Johnson, Jr. Jefferson, LA USA PGP Key ID 8834C06B I prefer encrypted mail. "If thine enemy offend thee, give his child a drum." Chinese Curse
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