* RT patch and arch/i386/kernel/time.c question
@ 2006-03-07 16:42 Serge Noiraud
2006-03-07 17:23 ` Steven Rostedt
0 siblings, 1 reply; 3+ messages in thread
From: Serge Noiraud @ 2006-03-07 16:42 UTC (permalink / raw)
To: linux-kernel, ltt-dev; +Cc: Ingo Molnar, Mathieu Desnoyers
hi,
I'm trying to port the LTTng patch over the rt20 and I got the following problem :
The LTTng patch try to modify the arch/i386/kernel/time.c file in which the
timer_interrupt function doesn't exist anymore.
In which file / function could I try to patch the equivalent function ?
--
Serge Noiraud
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: RT patch and arch/i386/kernel/time.c question
2006-03-07 16:42 RT patch and arch/i386/kernel/time.c question Serge Noiraud
@ 2006-03-07 17:23 ` Steven Rostedt
2006-03-07 17:45 ` Mathieu Desnoyers
0 siblings, 1 reply; 3+ messages in thread
From: Steven Rostedt @ 2006-03-07 17:23 UTC (permalink / raw)
To: Serge Noiraud; +Cc: linux-kernel, ltt-dev, Ingo Molnar, Mathieu Desnoyers
On Tue, 7 Mar 2006, Serge Noiraud wrote:
> hi,
>
> I'm trying to port the LTTng patch over the rt20 and I got the following problem :
> The LTTng patch try to modify the arch/i386/kernel/time.c file in which the
> timer_interrupt function doesn't exist anymore.
>
> In which file / function could I try to patch the equivalent function ?
>
The -rt patch uses the lastest stuff from Thomas Gleixner, John Stultz and
of course Ingo Molnar. The functions you are interested in, are in
kernel/time/ directory. Take a look at clockevents.c and perhaps
handle_tick(). I'm not sure what LTTng is doing there, but this will give
you a direction in which way to look.
-- Steve
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: RT patch and arch/i386/kernel/time.c question
2006-03-07 17:23 ` Steven Rostedt
@ 2006-03-07 17:45 ` Mathieu Desnoyers
0 siblings, 0 replies; 3+ messages in thread
From: Mathieu Desnoyers @ 2006-03-07 17:45 UTC (permalink / raw)
To: Steven Rostedt; +Cc: Serge Noiraud, linux-kernel, ltt-dev, Ingo Molnar
* Steven Rostedt (rostedt@goodmis.org) wrote:
>
> On Tue, 7 Mar 2006, Serge Noiraud wrote:
>
> > hi,
> >
> > I'm trying to port the LTTng patch over the rt20 and I got the following problem :
> > The LTTng patch try to modify the arch/i386/kernel/time.c file in which the
> > timer_interrupt function doesn't exist anymore.
> >
> > In which file / function could I try to patch the equivalent function ?
> >
>
> The -rt patch uses the lastest stuff from Thomas Gleixner, John Stultz and
> of course Ingo Molnar. The functions you are interested in, are in
> kernel/time/ directory. Take a look at clockevents.c and perhaps
> handle_tick(). I'm not sure what LTTng is doing there, but this will give
> you a direction in which way to look.
>
> -- Steve
>
LTTng is updating its logical clock there. Note that this clock is only used on
architectures missing a synchronised CPU timestamp counter (NUMA and old i586).
If you have a fairly standard architecture (i686 with TSC available), this
combination of jiffies counter and logical clock is not used.
Look for where the xtime_lock seqlock is taken in the -rt patch : that's where
the logical clock should be updated.
Mathieu
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^ permalink raw reply [flat|nested] 3+ messages in thread
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2006-03-07 16:42 RT patch and arch/i386/kernel/time.c question Serge Noiraud
2006-03-07 17:23 ` Steven Rostedt
2006-03-07 17:45 ` Mathieu Desnoyers
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