Re: [ANNOUNCE] ktimers subsystem

Thomas Gleixner
2005-09-20T05:11:11Z

On Mon, 2005-09-19 at 22:57 -0600, Christopher Friesen wrote:
> >>--flight-recorder style logs
>
> > If you want to implement such stuff efficiently you rely on rdtscll() on
> > x86 or other monotonic easy accessible time souces and not on a
> > permanent call to gettimeofday.
>
> Not portable across architectures, and doesn't work across all smp/numa
> environments. Also not easy to compare with other nodes on the network,
> whereas with ntp-synch'd nodes you can use gettimeofday() for quite
> accurate correlations.

Sorry was a stupid argument. Withdrawn herby

> > Please beware me of red herrings. If application developers code with
> > respect to random OS worst case behaviour then they should not complain
> > that OS N is having an additional add instruction in one of the pathes.
>
> Actually I'm not complaining about additional add instructions. I was
> just suggesting some reasons why apps might reasonably want to know the
> time frequently.

ok

tglx