Re: [ANNOUNCE] ktimers subsystem

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hi!

> > 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.

Eh? One addition is going to be lost in noise compared to syscall overhead.
(For vsyscall, you may be closer to truth, but I doubt it. You could still gain
more than one addition by using some strange calling convention).


-- 
64 bytes from 195.113.31.123: icmp_seq=28 ttl=51 time=448769.1 ms         

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]
  Powered by Linux