Re: [ANNOUNCE] ktimers subsystem

Christoph Lameter
2005-09-19T22:24:57Z

On Tue, 20 Sep 2005, Thomas Gleixner wrote:

> Also the basic prerequisite for for high resolution timers is a fast and
> simple access to clock_monotonic rather than to a backward corrected
> clock_realtime representation.

Yup that may be a reason to tolerate the add for realtime.

> We should rather ask glibc people why gettimeofday() / clock_getttime()
> is called inside the library code all over the place for non obvious
> reasons.

You can ask lots of application vendors the same question because its all
over lots of user space code. The fact is that gettimeofday() /
clock_gettime() efficiency is very critical to the performance of many
applications on Linux. That is why the addtion of one add instruction may
better be carefully considered. Many platforms can execute gettimeofday
without having to enter the kernel.