* [Xenomai-help] Xenomai port to SH4
@ 2006-04-18 14:11 Kiichi Kameda
2006-04-17 14:33 ` Philippe Gerum
2006-04-17 14:52 ` Jan Kiszka
0 siblings, 2 replies; 6+ messages in thread
From: Kiichi Kameda @ 2006-04-18 14:11 UTC (permalink / raw)
To: xenomai
I have been porting Xenomai-2.0.2 to SH(SuperH) architecture.
Currently almost all functions work well. And, I am mesuring the performance
from user-space program using posix skin on a 240MHz SH7750R(SH4) machine,
mainly 1 ms periodic dispatch latency. The measured data shows small
latency(tens of micro seconds) when system has a light workload.
In case of heavy workload such as frequent linux command input, the latency
increases to some 200 micro seconds, though.
Following is the testsuit/latency/latency program(using native skin -
slightly modified) output with comment.
In case of posix skin, the data shows similar tendency.
RTH|-----lat min|-----lat avg|-----lat max|-overrun|----lat best|---lat
worst
...(no workload)
RTD| 333| 1400| 9733| 0| 333|
27066
RTD| 333| 1466| 34533| 0| 333|
34533
RTD| 266| 1400| 14533| 0| 266|
34533
RTD| 400| 1400| 14466| 0| 266|
34533
RTD| 333| 1333| 7533| 0| 266|
34533
RTD| 266| 1400| 14333| 0| 266|
34533
RTD| 333| 1400| 40866| 0| 266|
40866
RTD| 333| 1466| 25533| 0| 266|
40866
RTD| 266| 1400| 14400| 0| 266|
40866
RTD| 400| 1400| 13600| 0| 266|
40866
RTD| 266| 1400| 7466| 0| 266|
40866
RTD| 333| 1466| 40800| 0| 266|
40866
RTD| 333| 1400| 18466| 0| 266|
40866
RTD| 333| 1400| 13533| 0| 266|
40866
...
RTD| 333| 1333| 7133| 0| 266|
40866
(telnet login)
RTD| 266| 4400| 111000| 0| 266|
111000
RTD| 333| 1400| 27266| 0| 266|
111000
RTD| 333| 1466| 28000| 0| 266|
111000
RTD| 333| 1466| 33133| 0| 266|
111000
RTD| 333| 1466| 26800| 0| 266|
111000
(single ps aux command)
RTD| 333| 22800| 112533| 0| 266|
112533
RTD| 333| 1400| 19400| 0| 266|
112533
RTD| 266| 1466| 35000| 0| 266|
112533
RTD| 333| 1400| 7533| 0| 266|
112533
RTD| 333| 1400| 15733| 0| 266|
112533
RTD| 266| 1866| 71333| 0| 266|
112533
RTD| 333| 9866| 105866| 0| 266|
112533
RTD| 266| 1400| 14400| 0| 266|
112533
RTD| 266| 1400| 11266| 0| 266|
112533
RTD| 400| 1466| 50133| 0| 266|
112533
RTD| 333| 3066| 116866| 0| 266|
116866
(successive ps aux command)
RTD| 1266| 15933| 218866| 0| 266|
218866
RTD| 1266| 2400| 76666| 0| 266|
218866
RTD| 333| 1400| 15000| 0| 266|
218866
RTD| 266| 1400| 27600| 0| 266|
218866
RTD| 400| 1400| 15333| 0| 266|
218866
RTD| 266| 1333| 6933| 0| 266|
218866
RTD| 333| 1400| 16533| 0| 266|
218866
RTD| 400| 1800| 75933| 0| 266|
218866
It is enough possible I have misported the Xenomai to SH, but I also think
Xenomai user-space program(primary mode) suffers such extra latency when
Linux kernel runs Linux programs.
I will appreciate any suggestion for latency improvement.
Thank you,
Kiichi Kameda
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Xenomai-help] Xenomai port to SH4
2006-04-18 14:11 [Xenomai-help] Xenomai port to SH4 Kiichi Kameda
@ 2006-04-17 14:33 ` Philippe Gerum
2006-04-19 14:00 ` Kiichi Kameda
2006-04-17 14:52 ` Jan Kiszka
1 sibling, 1 reply; 6+ messages in thread
From: Philippe Gerum @ 2006-04-17 14:33 UTC (permalink / raw)
To: Kiichi Kameda; +Cc: xenomai
Kiichi Kameda wrote:
> I have been porting Xenomai-2.0.2 to SH(SuperH) architecture.
> Currently almost all functions work well. And, I am mesuring the performance
> from user-space program using posix skin on a 240MHz SH7750R(SH4) machine,
> mainly 1 ms periodic dispatch latency. The measured data shows small
> latency(tens of micro seconds) when system has a light workload.
> In case of heavy workload such as frequent linux command input, the latency
> increases to some 200 micro seconds, though.
>
> Following is the testsuit/latency/latency program(using native skin -
> slightly modified) output with comment.
> In case of posix skin, the data shows similar tendency.
>
> RTH|-----lat min|-----lat avg|-----lat max|-overrun|----lat best|---lat
> worst
> ...(no workload)
> RTD| 333| 1400| 9733| 0| 333|
> 27066
> RTD| 333| 1466| 34533| 0| 333|
> 34533
> RTD| 266| 1400| 14533| 0| 266|
> 34533
> RTD| 400| 1400| 14466| 0| 266|
> 34533
> RTD| 333| 1333| 7533| 0| 266|
> 34533
> RTD| 266| 1400| 14333| 0| 266|
> 34533
> RTD| 333| 1400| 40866| 0| 266|
> 40866
> RTD| 333| 1466| 25533| 0| 266|
> 40866
> RTD| 266| 1400| 14400| 0| 266|
> 40866
> RTD| 400| 1400| 13600| 0| 266|
> 40866
> RTD| 266| 1400| 7466| 0| 266|
> 40866
> RTD| 333| 1466| 40800| 0| 266|
> 40866
> RTD| 333| 1400| 18466| 0| 266|
> 40866
> RTD| 333| 1400| 13533| 0| 266|
> 40866
> ...
> RTD| 333| 1333| 7133| 0| 266|
> 40866
> (telnet login)
> RTD| 266| 4400| 111000| 0| 266|
> 111000
> RTD| 333| 1400| 27266| 0| 266|
> 111000
> RTD| 333| 1466| 28000| 0| 266|
> 111000
>
> RTD| 333| 1466| 33133| 0| 266|
> 111000
> RTD| 333| 1466| 26800| 0| 266|
> 111000
> (single ps aux command)
> RTD| 333| 22800| 112533| 0| 266|
> 112533
> RTD| 333| 1400| 19400| 0| 266|
> 112533
> RTD| 266| 1466| 35000| 0| 266|
> 112533
> RTD| 333| 1400| 7533| 0| 266|
> 112533
> RTD| 333| 1400| 15733| 0| 266|
> 112533
> RTD| 266| 1866| 71333| 0| 266|
> 112533
> RTD| 333| 9866| 105866| 0| 266|
> 112533
> RTD| 266| 1400| 14400| 0| 266|
> 112533
>
> RTD| 266| 1400| 11266| 0| 266|
> 112533
> RTD| 400| 1466| 50133| 0| 266|
> 112533
> RTD| 333| 3066| 116866| 0| 266|
> 116866
> (successive ps aux command)
> RTD| 1266| 15933| 218866| 0| 266|
> 218866
> RTD| 1266| 2400| 76666| 0| 266|
> 218866
> RTD| 333| 1400| 15000| 0| 266|
> 218866
> RTD| 266| 1400| 27600| 0| 266|
> 218866
> RTD| 400| 1400| 15333| 0| 266|
> 218866
> RTD| 266| 1333| 6933| 0| 266|
> 218866
> RTD| 333| 1400| 16533| 0| 266|
> 218866
> RTD| 400| 1800| 75933| 0| 266|
> 218866
>
>
> It is enough possible I have misported the Xenomai to SH, but I also think
> Xenomai user-space program(primary mode) suffers such extra latency when
> Linux kernel runs Linux programs.
>
Likely cache management issues.
> I will appreciate any suggestion for latency improvement.
>
Any code to share with us, Adeos/sh4 for instance?
> Thank you,
>
> Kiichi Kameda
>
>
> _______________________________________________
> Xenomai-help mailing list
> Xenomai-help@domain.hid
> https://mail.gna.org/listinfo/xenomai-help
>
--
Philippe.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Xenomai-help] Xenomai port to SH4
2006-04-17 14:33 ` Philippe Gerum
@ 2006-04-19 14:00 ` Kiichi Kameda
2006-04-18 14:04 ` Philippe Gerum
0 siblings, 1 reply; 6+ messages in thread
From: Kiichi Kameda @ 2006-04-19 14:00 UTC (permalink / raw)
To: Philippe Gerum; +Cc: xenomai
>
> Any code to share with us, Adeos/sh4 for instance?
>
I think so. but please wait for a while,
Although current code is enough for my application, there are a couple of
features
that has to be tested or implemented to be available for you.
CONFIG_PREEMPT
Floating Point register context
oneshot timer
When finished, SH3 will also be supported.
----- Original Message -----
From: "Philippe Gerum" <rpm@xenomai.org>
To: "Kiichi Kameda" <k-kameda@domain.hid>
Cc: <xenomai@xenomai.org>
Sent: Monday, April 17, 2006 11:33 PM
Subject: Re: [Xenomai-help] Xenomai port to SH4
> Kiichi Kameda wrote:
> > I have been porting Xenomai-2.0.2 to SH(SuperH) architecture.
> > Currently almost all functions work well. And, I am mesuring the
performance
> > from user-space program using posix skin on a 240MHz SH7750R(SH4)
machine,
> > mainly 1 ms periodic dispatch latency. The measured data shows small
> > latency(tens of micro seconds) when system has a light workload.
> > In case of heavy workload such as frequent linux command input, the
latency
> > increases to some 200 micro seconds, though.
> >
> > Following is the testsuit/latency/latency program(using native skin -
> > slightly modified) output with comment.
> > In case of posix skin, the data shows similar tendency.
> >
> > RTH|-----lat min|-----lat avg|-----lat max|-overrun|----lat best|---lat
> > worst
> > ...(no workload)
> > RTD| 333| 1400| 9733| 0| 333|
> > 27066
> > RTD| 333| 1466| 34533| 0| 333|
> > 34533
> > RTD| 266| 1400| 14533| 0| 266|
> > 34533
> > RTD| 400| 1400| 14466| 0| 266|
> > 34533
> > RTD| 333| 1333| 7533| 0| 266|
> > 34533
> > RTD| 266| 1400| 14333| 0| 266|
> > 34533
> > RTD| 333| 1400| 40866| 0| 266|
> > 40866
> > RTD| 333| 1466| 25533| 0| 266|
> > 40866
> > RTD| 266| 1400| 14400| 0| 266|
> > 40866
> > RTD| 400| 1400| 13600| 0| 266|
> > 40866
> > RTD| 266| 1400| 7466| 0| 266|
> > 40866
> > RTD| 333| 1466| 40800| 0| 266|
> > 40866
> > RTD| 333| 1400| 18466| 0| 266|
> > 40866
> > RTD| 333| 1400| 13533| 0| 266|
> > 40866
> > ...
> > RTD| 333| 1333| 7133| 0| 266|
> > 40866
> > (telnet login)
> > RTD| 266| 4400| 111000| 0| 266|
> > 111000
> > RTD| 333| 1400| 27266| 0| 266|
> > 111000
> > RTD| 333| 1466| 28000| 0| 266|
> > 111000
> >
> > RTD| 333| 1466| 33133| 0| 266|
> > 111000
> > RTD| 333| 1466| 26800| 0| 266|
> > 111000
> > (single ps aux command)
> > RTD| 333| 22800| 112533| 0| 266|
> > 112533
> > RTD| 333| 1400| 19400| 0| 266|
> > 112533
> > RTD| 266| 1466| 35000| 0| 266|
> > 112533
> > RTD| 333| 1400| 7533| 0| 266|
> > 112533
> > RTD| 333| 1400| 15733| 0| 266|
> > 112533
> > RTD| 266| 1866| 71333| 0| 266|
> > 112533
> > RTD| 333| 9866| 105866| 0| 266|
> > 112533
> > RTD| 266| 1400| 14400| 0| 266|
> > 112533
> >
> > RTD| 266| 1400| 11266| 0| 266|
> > 112533
> > RTD| 400| 1466| 50133| 0| 266|
> > 112533
> > RTD| 333| 3066| 116866| 0| 266|
> > 116866
> > (successive ps aux command)
> > RTD| 1266| 15933| 218866| 0| 266|
> > 218866
> > RTD| 1266| 2400| 76666| 0| 266|
> > 218866
> > RTD| 333| 1400| 15000| 0| 266|
> > 218866
> > RTD| 266| 1400| 27600| 0| 266|
> > 218866
> > RTD| 400| 1400| 15333| 0| 266|
> > 218866
> > RTD| 266| 1333| 6933| 0| 266|
> > 218866
> > RTD| 333| 1400| 16533| 0| 266|
> > 218866
> > RTD| 400| 1800| 75933| 0| 266|
> > 218866
> >
> >
> > It is enough possible I have misported the Xenomai to SH, but I also
think
> > Xenomai user-space program(primary mode) suffers such extra latency when
> > Linux kernel runs Linux programs.
> >
>
> Likely cache management issues.
>
> > I will appreciate any suggestion for latency improvement.
> >
>
> Any code to share with us, Adeos/sh4 for instance?
>
> > Thank you,
> >
> > Kiichi Kameda
> >
> >
> > _______________________________________________
> > Xenomai-help mailing list
> > Xenomai-help@domain.hid
> > https://mail.gna.org/listinfo/xenomai-help
> >
>
>
> --
>
> Philippe.
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Xenomai-help] Xenomai port to SH4
2006-04-19 14:00 ` Kiichi Kameda
@ 2006-04-18 14:04 ` Philippe Gerum
0 siblings, 0 replies; 6+ messages in thread
From: Philippe Gerum @ 2006-04-18 14:04 UTC (permalink / raw)
To: Kiichi Kameda; +Cc: xenomai
Kiichi Kameda wrote:
>>Any code to share with us, Adeos/sh4 for instance?
>>
>
>
> I think so. but please wait for a while,
No problem, by definition, you own your code anyway. This was just a
reminder that it's easier to discuss technical matters and get help from
people when they have something to look at in the first place.
> Although current code is enough for my application, there are a couple of
> features
> that has to be tested or implemented to be available for you.
> CONFIG_PREEMPT
> Floating Point register context
> oneshot timer
> When finished, SH3 will also be supported.
>
Ack. TIA, then.
>
> ----- Original Message -----
> From: "Philippe Gerum" <rpm@xenomai.org>
> To: "Kiichi Kameda" <k-kameda@domain.hid>
> Cc: <xenomai@xenomai.org>
> Sent: Monday, April 17, 2006 11:33 PM
> Subject: Re: [Xenomai-help] Xenomai port to SH4
>
>
>
>>Kiichi Kameda wrote:
>>
>>>I have been porting Xenomai-2.0.2 to SH(SuperH) architecture.
>>>Currently almost all functions work well. And, I am mesuring the
>
> performance
>
>>>from user-space program using posix skin on a 240MHz SH7750R(SH4)
>
> machine,
>
>>>mainly 1 ms periodic dispatch latency. The measured data shows small
>>>latency(tens of micro seconds) when system has a light workload.
>>>In case of heavy workload such as frequent linux command input, the
>
> latency
>
>>>increases to some 200 micro seconds, though.
>>>
>>>Following is the testsuit/latency/latency program(using native skin -
>>>slightly modified) output with comment.
>>>In case of posix skin, the data shows similar tendency.
>>>
>>>RTH|-----lat min|-----lat avg|-----lat max|-overrun|----lat best|---lat
>>>worst
>>>...(no workload)
>>>RTD| 333| 1400| 9733| 0| 333|
>>>27066
>>>RTD| 333| 1466| 34533| 0| 333|
>>>34533
>>>RTD| 266| 1400| 14533| 0| 266|
>>>34533
>>>RTD| 400| 1400| 14466| 0| 266|
>>>34533
>>>RTD| 333| 1333| 7533| 0| 266|
>>>34533
>>>RTD| 266| 1400| 14333| 0| 266|
>>>34533
>>>RTD| 333| 1400| 40866| 0| 266|
>>>40866
>>>RTD| 333| 1466| 25533| 0| 266|
>>>40866
>>>RTD| 266| 1400| 14400| 0| 266|
>>>40866
>>>RTD| 400| 1400| 13600| 0| 266|
>>>40866
>>>RTD| 266| 1400| 7466| 0| 266|
>>>40866
>>>RTD| 333| 1466| 40800| 0| 266|
>>>40866
>>>RTD| 333| 1400| 18466| 0| 266|
>>>40866
>>>RTD| 333| 1400| 13533| 0| 266|
>>>40866
>>>...
>>>RTD| 333| 1333| 7133| 0| 266|
>>>40866
>>>(telnet login)
>>>RTD| 266| 4400| 111000| 0| 266|
>>>111000
>>>RTD| 333| 1400| 27266| 0| 266|
>>>111000
>>>RTD| 333| 1466| 28000| 0| 266|
>>>111000
>>>
>>>RTD| 333| 1466| 33133| 0| 266|
>>>111000
>>>RTD| 333| 1466| 26800| 0| 266|
>>>111000
>>>(single ps aux command)
>>>RTD| 333| 22800| 112533| 0| 266|
>>>112533
>>>RTD| 333| 1400| 19400| 0| 266|
>>>112533
>>>RTD| 266| 1466| 35000| 0| 266|
>>>112533
>>>RTD| 333| 1400| 7533| 0| 266|
>>>112533
>>>RTD| 333| 1400| 15733| 0| 266|
>>>112533
>>>RTD| 266| 1866| 71333| 0| 266|
>>>112533
>>>RTD| 333| 9866| 105866| 0| 266|
>>>112533
>>>RTD| 266| 1400| 14400| 0| 266|
>>>112533
>>>
>>>RTD| 266| 1400| 11266| 0| 266|
>>>112533
>>>RTD| 400| 1466| 50133| 0| 266|
>>>112533
>>>RTD| 333| 3066| 116866| 0| 266|
>>>116866
>>>(successive ps aux command)
>>>RTD| 1266| 15933| 218866| 0| 266|
>>>218866
>>>RTD| 1266| 2400| 76666| 0| 266|
>>>218866
>>>RTD| 333| 1400| 15000| 0| 266|
>>>218866
>>>RTD| 266| 1400| 27600| 0| 266|
>>>218866
>>>RTD| 400| 1400| 15333| 0| 266|
>>>218866
>>>RTD| 266| 1333| 6933| 0| 266|
>>>218866
>>>RTD| 333| 1400| 16533| 0| 266|
>>>218866
>>>RTD| 400| 1800| 75933| 0| 266|
>>>218866
>>>
>>>
>>>It is enough possible I have misported the Xenomai to SH, but I also
>
> think
>
>>>Xenomai user-space program(primary mode) suffers such extra latency when
>>>Linux kernel runs Linux programs.
>>>
>>
>>Likely cache management issues.
>>
>>
>>>I will appreciate any suggestion for latency improvement.
>>>
>>
>>Any code to share with us, Adeos/sh4 for instance?
>>
>>
>>>Thank you,
>>>
>>>Kiichi Kameda
>>>
>>>
>>>_______________________________________________
>>>Xenomai-help mailing list
>>>Xenomai-help@domain.hid
>>>https://mail.gna.org/listinfo/xenomai-help
>>>
>>
>>
>>--
>>
>>Philippe.
>>
>
>
>
--
Philippe.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Xenomai-help] Xenomai port to SH4
2006-04-18 14:11 [Xenomai-help] Xenomai port to SH4 Kiichi Kameda
2006-04-17 14:33 ` Philippe Gerum
@ 2006-04-17 14:52 ` Jan Kiszka
2006-04-19 14:49 ` Kiichi Kameda
1 sibling, 1 reply; 6+ messages in thread
From: Jan Kiszka @ 2006-04-17 14:52 UTC (permalink / raw)
To: Kiichi Kameda; +Cc: xenomai
[-- Attachment #1: Type: text/plain, Size: 5249 bytes --]
Kiichi Kameda wrote:
> I have been porting Xenomai-2.0.2 to SH(SuperH) architecture.
Cool!
> Currently almost all functions work well. And, I am mesuring the performance
> from user-space program using posix skin on a 240MHz SH7750R(SH4) machine,
> mainly 1 ms periodic dispatch latency. The measured data shows small
> latency(tens of micro seconds) when system has a light workload.
> In case of heavy workload such as frequent linux command input, the latency
> increases to some 200 micro seconds, though.
If you are looking for real heavy load: cache benchmarks tend to stress
your system most (e.g. http://www.cwi.nl/~manegold/Calibrator). Combine
them with heavy i/o load (flood ping etc.).
Anyway, 200 us for a 240 MHz system doesn't sound totally unrealistic.
But I do not know the sh4 architecture to give a reliable estimation.
What are your numbers when running latency in the other modes, i.e.
without the need to switch to user space (mode 1, "-t1") or even without
any context switch at all (mode 2, "-t2")?
>
> Following is the testsuit/latency/latency program(using native skin -
> slightly modified) output with comment.
> In case of posix skin, the data shows similar tendency.
>
> RTH|-----lat min|-----lat avg|-----lat max|-overrun|----lat best|---lat
> worst
> ...(no workload)
> RTD| 333| 1400| 9733| 0| 333|
> 27066
> RTD| 333| 1466| 34533| 0| 333|
> 34533
> RTD| 266| 1400| 14533| 0| 266|
> 34533
> RTD| 400| 1400| 14466| 0| 266|
> 34533
> RTD| 333| 1333| 7533| 0| 266|
> 34533
> RTD| 266| 1400| 14333| 0| 266|
> 34533
> RTD| 333| 1400| 40866| 0| 266|
> 40866
> RTD| 333| 1466| 25533| 0| 266|
> 40866
> RTD| 266| 1400| 14400| 0| 266|
> 40866
> RTD| 400| 1400| 13600| 0| 266|
> 40866
> RTD| 266| 1400| 7466| 0| 266|
> 40866
> RTD| 333| 1466| 40800| 0| 266|
> 40866
> RTD| 333| 1400| 18466| 0| 266|
> 40866
> RTD| 333| 1400| 13533| 0| 266|
> 40866
> ...
> RTD| 333| 1333| 7133| 0| 266|
> 40866
> (telnet login)
> RTD| 266| 4400| 111000| 0| 266|
> 111000
> RTD| 333| 1400| 27266| 0| 266|
> 111000
> RTD| 333| 1466| 28000| 0| 266|
> 111000
>
> RTD| 333| 1466| 33133| 0| 266|
> 111000
> RTD| 333| 1466| 26800| 0| 266|
> 111000
> (single ps aux command)
> RTD| 333| 22800| 112533| 0| 266|
> 112533
> RTD| 333| 1400| 19400| 0| 266|
> 112533
> RTD| 266| 1466| 35000| 0| 266|
> 112533
> RTD| 333| 1400| 7533| 0| 266|
> 112533
> RTD| 333| 1400| 15733| 0| 266|
> 112533
> RTD| 266| 1866| 71333| 0| 266|
> 112533
> RTD| 333| 9866| 105866| 0| 266|
> 112533
> RTD| 266| 1400| 14400| 0| 266|
> 112533
>
> RTD| 266| 1400| 11266| 0| 266|
> 112533
> RTD| 400| 1466| 50133| 0| 266|
> 112533
> RTD| 333| 3066| 116866| 0| 266|
> 116866
> (successive ps aux command)
> RTD| 1266| 15933| 218866| 0| 266|
> 218866
> RTD| 1266| 2400| 76666| 0| 266|
> 218866
> RTD| 333| 1400| 15000| 0| 266|
> 218866
> RTD| 266| 1400| 27600| 0| 266|
> 218866
> RTD| 400| 1400| 15333| 0| 266|
> 218866
> RTD| 266| 1333| 6933| 0| 266|
> 218866
> RTD| 333| 1400| 16533| 0| 266|
> 218866
> RTD| 400| 1800| 75933| 0| 266|
> 218866
>
>
> It is enough possible I have misported the Xenomai to SH, but I also think
> Xenomai user-space program(primary mode) suffers such extra latency when
> Linux kernel runs Linux programs.
>
> I will appreciate any suggestion for latency improvement.
Very helpful for understanding what happens on your system is the ipipe
latency tracer. We have support for x86 and ppc so far, and there are
"templates" for porting it to other archs available from Ingo Molnar's
original patch. Unfortunately, even the latter does not yet include sh4
support, so porting it would be a real pioneer work. :)
But, basically, it can be as simple as writing an mcount stub in
assembly to call the actual tracing function. See x86 on this.
Jan
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^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Xenomai-help] Xenomai port to SH4
2006-04-17 14:52 ` Jan Kiszka
@ 2006-04-19 14:49 ` Kiichi Kameda
0 siblings, 0 replies; 6+ messages in thread
From: Kiichi Kameda @ 2006-04-19 14:49 UTC (permalink / raw)
To: Jan Kiszka; +Cc: xenomai
Hi,
> If you are looking for real heavy load: cache benchmarks tend to stress
> your system most (e.g. http://www.cwi.nl/~manegold/Calibrator). Combine
> them with heavy i/o load (flood ping etc.).
>
> Anyway, 200 us for a 240 MHz system doesn't sound totally unrealistic.
> But I do not know the sh4 architecture to give a reliable estimation.
>
> What are your numbers when running latency in the other modes, i.e.
> without the need to switch to user space (mode 1, "-t1") or even without
> any context switch at all (mode 2, "-t2")?
The machine is a small embedded device that has various IOs, and I expect
my user space application program runs 1ms periodically.
So jitter is important when I execute telnet login and run common linux
commands.
By the way, the latency was improved a little.
I found linux system call handler run with interrupt masked.
By adding the code to enable interrupt to entry.S which is architecture
specific,
the latency is no more than 150us on the same conditions as in my last
mail.
Thanks,
Kiichi Kameda
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2006-04-19 14:49 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2006-04-18 14:11 [Xenomai-help] Xenomai port to SH4 Kiichi Kameda
2006-04-17 14:33 ` Philippe Gerum
2006-04-19 14:00 ` Kiichi Kameda
2006-04-18 14:04 ` Philippe Gerum
2006-04-17 14:52 ` Jan Kiszka
2006-04-19 14:49 ` Kiichi Kameda
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