lkml.org 
[lkml]   [2005]   [Sep]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [ANNOUNCE] ktimers subsystem
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 majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-09-22 12:35    [from the cache]
©2003-2011 Jasper Spaans