All of lore.kernel.org
 help / color / mirror / Atom feed
* [Xenomai-core] getting negative values in interrupt latency in xenomai
@ 2007-05-23  6:10 manoj kumar
  2007-05-23  7:25 ` Gregory CLEMENT
  0 siblings, 1 reply; 3+ messages in thread
From: manoj kumar @ 2007-05-23  6:10 UTC (permalink / raw)
  To: xenomai

[-- Attachment #1: Type: text/plain, Size: 1878 bytes --]

Hi,

i am runnigthe latency test on i386 platform with 1 GB ram and intel pentium
4 runnig at 2.66GHz . i am getting some negative values as lat best and avg.
The results are as below

*    User space interrupt latency output*

*    == Sampling period: 10000 us*

*== Test mode: periodic user-mode task*

*== All results in microseconds*

*warming up...*

*RTT|  00:00:01  (periodic user-mode task, 10000 us period, priority 99)*

*RTH|-----lat min|-----lat avg|-----lat max|-overrun|----lat best|---lat
worst*

*RTD|      -1.775|      -1.374|       0.953|       0|      -1.775|
0.953*

*RTD|      -1.790|      -1.355|       3.142|       0|      -1.790|
3.142*

*RTD|      -1.812|      -1.266|       4.158|       0|      -1.812|
4.158*

*RTD|      -1.797|      -1.272|       6.602|       0|      -1.812|
6.602*

*RTD|      -1.764|      -1.365|       0.575|       0|      -1.812|
6.602*

*RTD|      -1.895|      -1.370|       0.859|       0|      -1.895|
6.602*

*RTD|      -1.857|      -1.421|       0.908|       0|      -1.895|
6.602*

*RTD|      -1.782|      -1.293|       5.845|       0|      -1.895|
6.602*

*RTD|      -1.929|      -1.362|       1.204|       0|      -1.929|
6.602*

*RTD|      -1.775|      -1.359|       0.844|       0|      -1.929|
6.602*

*RTD|      -1.794|      -1.346|       0.724|       0|      -1.929|
6.602*

*RTD|      -1.756|      -1.318|       1.021|       0|      -1.929|
6.602*

*RTD|      -1.775|      -1.269|       8.064|       0|      -1.929|
8.064*

*RTD|      -1.805|      -1.395|       0.893|       0|      -1.929|
8.064*

*RTD|      -1.779|       1.530|     281.147|       0|      -1.929|
281.147*

*RTD|      -1.959|      -1.362|       1.118|       0|      -1.959|
281.147*
Could any figure out why these negative values are coming and reason behind
that and how i can avoid these.

is it a configuration issuse.

Thanks & regards
Manoj

[-- Attachment #2: Type: text/html, Size: 12751 bytes --]

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [Xenomai-core] getting negative values in interrupt latency in xenomai
  2007-05-23  6:10 [Xenomai-core] getting negative values in interrupt latency in xenomai manoj kumar
@ 2007-05-23  7:25 ` Gregory CLEMENT
  2007-05-23  8:07   ` Jan Kiszka
  0 siblings, 1 reply; 3+ messages in thread
From: Gregory CLEMENT @ 2007-05-23  7:25 UTC (permalink / raw)
  To: manoj kumar; +Cc: xenomai

2007/5/23, manoj kumar <manojkpanghal@domain.hid>:
> Hi,
>
> i am runnigthe latency test on i386 platform with 1 GB ram and intel pentium
> 4 runnig at 2.66GHz . i am getting some negative values as lat best and avg.
> The results are as below
>
>
>     User space interrupt latency output
>
>     == Sampling period: 10000 us
>
> == Test mode: periodic user-mode task
>
> == All results in microseconds
>
> warming up...
>
> RTT|  00:00:01   (periodic user-mode task, 10000 us period, priority 99)
>
> RTH|-----lat min|-----lat avg|-----lat max|-overrun|----lat best|---lat
> worst
>
> RTD|      -1.775|       -1.374|       0.953|       0|      -1.775|
> 0.953
>
> RTD|      -1.790|      -1.355|       3.142|       0|      -1.790|
> 3.142
>
> RTD|      -1.812|       -1.266|       4.158|       0|      -1.812|
> 4.158
>
> RTD|      -1.797|       -1.272|       6.602|       0|      -1.812|
> 6.602
>
> RTD|      -1.764|       -1.365|       0.575|       0|      -1.812|
> 6.602
>
> RTD|      -1.895|       -1.370|       0.859|       0|      -1.895|
> 6.602
>
> RTD|      -1.857|       -1.421|       0.908|       0|      -1.895|
> 6.602
>
> RTD|      -1.782|       -1.293|       5.845|       0|      -1.895|
> 6.602
>
> RTD|      -1.929|       -1.362|       1.204|       0|      -1.929|
> 6.602
>
> RTD|      -1.775|       -1.359|       0.844|       0|      -1.929|
> 6.602
>
> RTD|      -1.794|       -1.346|       0.724|       0|      -1.929|
> 6.602
>
> RTD|      -1.756|      -1.318|       1.021|       0|      -1.929|
> 6.602
>
> RTD|      -1.775|       -1.269|       8.064|       0|      -1.929|
> 8.064
>
> RTD|      -1.805|       -1.395|       0.893|       0|      -1.929|
> 8.064
>
> RTD|      -1.779|        1.530|     281.147|       0|      -1.929|
> 281.147
>
> RTD|      -1.959|       -1.362|       1.118|       0|      -1.959|
> 281.147
> Could any figure out why these negative values are coming and reason behind
> that and how i can avoid these.
>
> is it a configuration issuse.

You have to calibrate xenomai by feeding with your average latency
/proc/xenomai/latency



>
> Thanks & regards
> Manoj


-- 
Gregory CLEMENT
Adeneo
2, chemin du Ruisseau - BP21
69136 Ecully Cedex
France
Tel : +33-4 72 18 08 40


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [Xenomai-core] getting negative values in interrupt latency in xenomai
  2007-05-23  7:25 ` Gregory CLEMENT
@ 2007-05-23  8:07   ` Jan Kiszka
  0 siblings, 0 replies; 3+ messages in thread
From: Jan Kiszka @ 2007-05-23  8:07 UTC (permalink / raw)
  Cc: manoj kumar, xenomai

Gregory CLEMENT wrote:
> 2007/5/23, manoj kumar <manojkpanghal@domain.hid>:
>> Hi,
>>
>> i am runnigthe latency test on i386 platform with 1 GB ram and intel pentium
>> 4 runnig at 2.66GHz . i am getting some negative values as lat best and avg.
>> The results are as below
>>
>>
>>     User space interrupt latency output
>>
>>     == Sampling period: 10000 us
>>
>> == Test mode: periodic user-mode task
>>
>> == All results in microseconds
>>
>> warming up...
>>
>> RTT|  00:00:01   (periodic user-mode task, 10000 us period, priority 99)
>>
>> RTH|-----lat min|-----lat avg|-----lat max|-overrun|----lat best|---lat
>> worst
>>
>> RTD|      -1.775|       -1.374|       0.953|       0|      -1.775|
>> 0.953
>>
>> RTD|      -1.790|      -1.355|       3.142|       0|      -1.790|
>> 3.142
>>
>> RTD|      -1.812|       -1.266|       4.158|       0|      -1.812|
>> 4.158
>>
>> RTD|      -1.797|       -1.272|       6.602|       0|      -1.812|
>> 6.602
>>
>> RTD|      -1.764|       -1.365|       0.575|       0|      -1.812|
>> 6.602
>>
>> RTD|      -1.895|       -1.370|       0.859|       0|      -1.895|
>> 6.602
>>
>> RTD|      -1.857|       -1.421|       0.908|       0|      -1.895|
>> 6.602
>>
>> RTD|      -1.782|       -1.293|       5.845|       0|      -1.895|
>> 6.602
>>
>> RTD|      -1.929|       -1.362|       1.204|       0|      -1.929|
>> 6.602
>>
>> RTD|      -1.775|       -1.359|       0.844|       0|      -1.929|
>> 6.602
>>
>> RTD|      -1.794|       -1.346|       0.724|       0|      -1.929|
>> 6.602
>>
>> RTD|      -1.756|      -1.318|       1.021|       0|      -1.929|
>> 6.602
>>
>> RTD|      -1.775|       -1.269|       8.064|       0|      -1.929|
>> 8.064
>>
>> RTD|      -1.805|       -1.395|       0.893|       0|      -1.929|
>> 8.064
>>
>> RTD|      -1.779|        1.530|     281.147|       0|      -1.929|
>> 281.147
>>
>> RTD|      -1.959|       -1.362|       1.118|       0|      -1.959|
>> 281.147
>> Could any figure out why these negative values are coming and reason behind
>> that and how i can avoid these.
>>
>> is it a configuration issuse.
> 
> You have to calibrate xenomai by feeding with your average latency
> /proc/xenomai/latency
> 

...or by setting it at compile time in the kernel .config.

Anyway, I would worry more about that +280 us latency. Probably
SMI-related. Please check TROUBLESHOOTING regarding potential reasons
and solutions.

Jan


^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2007-05-23  8:07 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2007-05-23  6:10 [Xenomai-core] getting negative values in interrupt latency in xenomai manoj kumar
2007-05-23  7:25 ` Gregory CLEMENT
2007-05-23  8:07   ` Jan Kiszka

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.