lkml.org 
[lkml]   [2003]   [Feb]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [RFC][PATCH] linux-2.5.59_getcycles_A0
On Sat, 8 Feb 2003, Andi Kleen wrote:

> Regarding the watchdog: what it basically wants is a POSIX
> CLOCK_MONOTONIC clock. This isn't currently implemented by Linux,
> but I expect it will be eventually because it's really useful for a lot
> of applications who just need an increasing time stamp in user space,
> and who do not want to fight ntpd for this. One example for such
> an application is the X server who needs this for its internal
> event sequencing.
>
> Implementing it based on the current time infrastructure is very easy -
> you just do not add xtime and wall jiffies in, but only jiffies.
>
> I don't think doing any special hacks and complicating get_cycles()
> for it is the right way. Just implement a new monotonic clock primitive
> (and eventually export it to user space too)

That seems to be the right way to go, rather than slow get_cycles() have a
separate functionality which does what you need. Didn't know about
CLOCK_MONOTONIC by that name, but I agree it's useful in various places.

--
bill davidsen <davidsen@tmr.com>
CTO, TMR Associates, Inc
Doing interesting things with little computers since 1979.

-
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: 2005-03-22 13:33    [W:0.345 / U:0.232 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site