Re: ktimers in RT causing bad bogomips and more.

From: Steven Rostedt
Date: Tue Oct 25 2005 - 17:37:07 EST


On Wed, 2005-10-26 at 00:26 +0200, Thomas Gleixner wrote:
> On Tue, 2005-10-25 at 18:15 -0400, Steven Rostedt wrote:
> > if (!hres->active)
> > return CLOCK_EVT_RUN_CYCLIC;
>
> I'm searching for the brown paperbag.
>
> Thats the startup code before switching over to high resolution, so it
> should return 1, nothing else.
>
> CLOCK_EVT_RUN_CYCLIC is a leftover of the initial implementation, which
> did not take tick overruns into account.

Here, I'll make it easy for you. ;-)

-- Steve

Index: rt_linux_ernie/kernel/ktimers.c
===================================================================
--- rt_linux_ernie.orig/kernel/ktimers.c 2005-10-25 18:31:51.000000000 -0400
+++ rt_linux_ernie/kernel/ktimers.c 2005-10-25 18:32:38.000000000 -0400
@@ -338,10 +338,9 @@
* we expect, that the event source is running in periodic
* mode when it is a source serving other (tick based)
* functionality than next event
- *
*/
if (!hres->active)
- return CLOCK_EVT_RUN_CYCLIC;
+ return 1;

now = do_ktime_get();



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