lkml.org 
[lkml]   [2006]   [Dec]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: realtime-preempt and arm

* tike64 <tike64@yahoo.com> wrote:

> Steven Rostedt <rostedt@goodmis.org> wrote:
> > Also, have you tried this with a nanosleep instead of a select.
> > Select's timeout is just that, a timeout. It's not suppose to be
> > accurate, as long as it doesn't expire early. The reason I state
> > this, is that select uses a different mechanism than nanosleep, and
> > that can indeed affect the jitter.
>
> Ok, understood; I tried this:
>
> t = raw_timer();
> ts.tv_nsec = 5000000;
> ts.tv_sec = 0;
> nanosleep(&ts, 0);
> t = raw_timer() - t;
>
> It is better but I still see 8ms occasional delays when listing
> nfs-mounted directories onto FB. And, what is funny, also this version
> makes the average delay 20ms as if it made the jiffy 20ms.

ARM has no high resolution timers support yet in the -rt tree.

Ingo
-
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: 2006-12-14 11:05    [W:0.062 / U:0.088 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site