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* [Xenomai-core] native syscalls
@ 2009-04-09  2:53 Steven Seeger
  2009-04-09  9:25 ` Gilles Chanteperdrix
  0 siblings, 1 reply; 3+ messages in thread
From: Steven Seeger @ 2009-04-09  2:53 UTC (permalink / raw)
  To: xenomai

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Can xenomai preempt its own system calls? We ran latency with our  
app.  We had a thread waiting on a cond, and when we signaled that  
cond, the latency jumped from ~70us to almost 400us even though  
latency runs a higher priority thread than the thread that we wake up.  
Is there interrupt disabling that accounts for this?

Here are the results as taken by Mark S.

== All results in microseconds
warming up...
RTT|  00:00:01  (periodic user-mode task, 100 us period, priority 99)
RTH|-----lat min|-----lat avg|-----lat max|-overrun|----lat best|--- 
lat worst
RTD|      14.934|      27.179|      65.767|       0|      14.934|       
65.767
RTD|      15.151|      26.798|      70.954|       0|      14.934|       
70.954
RTD|      15.409|      27.152|      66.890|       0|      14.934|       
70.954
RTD|      15.947|      27.316|      71.168|       0|      14.934|       
71.168
RTD|      15.746|      26.878|      71.188|       0|      14.934|       
71.188
RTD|      15.489|      26.631|      74.476|       0|      14.934|       
74.476
RTD|      16.659|      26.527|      67.425|       0|      14.934|       
74.476
RTD|      14.567|      26.972|      59.448|       0|      14.567|       
74.476
RTD|      15.987|      27.837|      74.092|       0|      14.567|       
74.476
RTD|      16.241|      28.352|      66.740|       0|      14.567|       
74.476
RTD|      13.982|      27.139|      65.630|       0|      13.982|       
74.476
RTD|      13.982|      33.355|      65.286|       3|      13.892|      
388.473
RTD|      13.982|      33.355|      65.286|       3|      13.892|      
388.473
RTD|      13.982|      33.355|      65.286|       3|      13.892|      
388.473
RTD|      13.982|      33.355|      65.286|       3|      13.892|      
388.473
RTD|      13.982|      33.355|      65.286|       3|      13.892|      
388.473
RTD|      13.791|      33.465|      67.351|       3|      12.702|      
388.473
RTD|      13.791|      33.465|      67.351|       3|      12.702|      
388.473
RTD|      13.791|      33.465|      67.351|       3|      12.702|      
388.473
RTD|      13.791|      33.465|      67.351|       3|      12.702|      
388.473
RTD|      13.761|      33.722|      90.066|       3|      12.702|      
388.473
RTT|  00:00:22  (periodic user-mode task, 100 us period, priority 99)
RTH|-----lat min|-----lat avg|-----lat max|-overrun|----lat best|--- 
lat worst
RTD|      13.283|      29.361|      59.140|       3|      12.702|      
388.473
RTD|      11.502|      29.040|      58.235|       3|      11.502|      
388.473
RTD|      10.530|      28.947|      67.027|       3|      10.530|      
388.473
RTD|      14.410|      31.760|      65.229|       3|      10.530|      
388.473
RTD|      13.207|      31.286|      73.607|       3|      10.530|      
388.473
RTD|      13.454|      30.678|      71.275|       3|      10.530|      
388.473
RTD|      14.730|      31.122|      64.090|       3|      10.530|      
388.473
RTD|      14.881|      30.397|      80.705|       3|      10.530|      
388.473
RTD|       9.848|      30.534|      66.659|       3|       9.848|      
388.473
RTD|      14.039|      30.678|      63.525|       3|       9.848|      
388.473
RTD|      13.290|      28.973|      71.589|       3|       9.848|      
388.473
RTD|      16.228|      23.957|      80.598|       3|       9.848|      
388.473
RTD|      17.304|      26.467|      74.018|       3|       9.848|      
388.473
RTD|      16.137|      26.494|      73.226|       3|       9.848|      
388.473
^ 
C 
---| 
------------| 
------------|------------|--------|-------------------------

Thanks,
Steven


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

* Re: [Xenomai-core] native syscalls
  2009-04-09  2:53 [Xenomai-core] native syscalls Steven Seeger
@ 2009-04-09  9:25 ` Gilles Chanteperdrix
  2009-04-09 11:02   ` Steven Seeger
  0 siblings, 1 reply; 3+ messages in thread
From: Gilles Chanteperdrix @ 2009-04-09  9:25 UTC (permalink / raw)
  To: Steven Seeger; +Cc: xenomai

Steven Seeger wrote:
> Can xenomai preempt its own system calls? We ran latency with our  
> app.  We had a thread waiting on a cond, and when we signaled that  
> cond, the latency jumped from ~70us to almost 400us even though  
> latency runs a higher priority thread than the thread that we wake up.  
> Is there interrupt disabling that accounts for this?
> 
> Here are the results as taken by Mark S.

As I told you in a voluntarily detailed private mail, only the traces
made by the I-pipe tracer are of any interest for us.

-- 
                                                 Gilles.


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

* Re: [Xenomai-core] native syscalls
  2009-04-09  9:25 ` Gilles Chanteperdrix
@ 2009-04-09 11:02   ` Steven Seeger
  0 siblings, 0 replies; 3+ messages in thread
From: Steven Seeger @ 2009-04-09 11:02 UTC (permalink / raw)
  To: Gilles Chanteperdrix; +Cc: xenomai

On Apr 9, 2009, at 5:25 AM, Gilles Chanteperdrix wrote:

> As I told you in a voluntarily detailed private mail, only the traces
> made by the I-pipe tracer are of any interest for us.

Gilles, I will send that email to Mark who has hardware to run on. I  
apologize for not doing this first but the email you speak of was lost  
among the 20 or so we had yesterday. :)

Steven




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

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Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2009-04-09  2:53 [Xenomai-core] native syscalls Steven Seeger
2009-04-09  9:25 ` Gilles Chanteperdrix
2009-04-09 11:02   ` Steven Seeger

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