From mboxrd@z Thu Jan  1 00:00:00 1970
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Date: Sat, 07 Jan 2006 19:42:54 +0100
From: Philippe Gerum <rpm@xenomai.org>
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Subject: [Xenomai-core] Re: [PATCH] reset tracer after timer calibration
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To: Jan Kiszka <jan.kiszka@domain.hid>
Cc: xenomai-core <xenomai@xenomai.org>

Jan Kiszka wrote:
> Jan Kiszka wrote:
> 
>>Hi Philippe,
>>
>>this patch is to reset the maximum IRQs-off path after timer calibration
>>(will get flooded otherwise). If you have no concerns, please apply.
>>

Applied, thanks.

>>Actually, there is another noise source: rthal_timer_request() for the
>>APIC case. But I think we should let this one alone as the user may
>>trigger millisecond latencies by accidentally restarting the timer while
>>some external-IRQ-driven device still depends on low latencies. In that
>>case, the tracer can provide helpful hints.
>>
>>Therefore, in order to get useful information after starting the timer,
>>one always have to run "echo > /proc/ipipe/trace/max" first. Well, if we
>>move the timer start to some module init or whatever phase also for the
>>native skin, we should reconsider this exclusion.
>>

We will do that right after -rc2, which is close now.

>>Jan
> 
> 
> and *with* the attachement...
> 
> 
> ------------------------------------------------------------------------
> 
> Index: ChangeLog
> ===================================================================
> --- ChangeLog	(Revision 388)
> +++ ChangeLog	(Arbeitskopie)
> @@ -7,6 +7,8 @@
>  	src/testsuite/latency/latency.c: Add re-freeze support and make use
>  	of it to back-trace always the max latency during benchmarks.
>  
> +	* ksrc/arch/i386/hal.c: reset tracer after timer calibration.
> +
>  2006-01-07  Heikki Lindholm <holindho@domain.hid>
>  
>  	* include/asm-powerpc/system.h: Fix FPU preemption bug.
> Index: ksrc/arch/i386/hal.c
> ===================================================================
> --- ksrc/arch/i386/hal.c	(Revision 386)
> +++ ksrc/arch/i386/hal.c	(Arbeitskopie)
> @@ -61,6 +61,9 @@
>  #endif /* CONFIG_X86_LOCAL_APIC */
>  #include <asm/xenomai/hal.h>
>  #include <stdarg.h>
> +#ifdef CONFIG_IPIPE_TRACE
> +#include <linux/ipipe_trace.h>
> +#endif /* CONFIG_IPIPE_TRACE */
>  
>  extern struct desc_struct idt_table[];
>  
> @@ -177,6 +180,11 @@
>  
>      rthal_critical_exit(flags);
>  
> +#ifdef CONFIG_IPIPE_TRACE_IRQSOFF
> +    /* reset the max trace, it contains the excessive calibration now */
> +    ipipe_trace_max_reset();
> +#endif /* CONFIG_IPIPE_TRACE_IRQSOFF */
> +
>      return rthal_imuldiv(dt,100000,RTHAL_CPU_FREQ);
>  }
>  
> @@ -345,6 +353,11 @@
>  
>      rthal_critical_exit(flags);
>  
> +#ifdef CONFIG_IPIPE_TRACE_IRQSOFF
> +    /* reset the max trace, it contains the excessive calibration now */
> +    ipipe_trace_max_reset();
> +#endif /* CONFIG_IPIPE_TRACE_IRQSOFF */
> +
>      return rthal_imuldiv(dt,100000,RTHAL_CPU_FREQ);
>  }
>  


-- 

Philippe.