Hello,
poornima r wrote:
Hello,
These were the scheduling latency and interrupt
latency test results on ppc and x86 with IPIPE tracer
option disabled.
1.Please comment on these results (whether valid) and
Your results are OK. These are actually the figures I remember from my
own tests in the past.
2.Is there any method to optimize these results.
No that I know of. There are a few ideas how to reduce latencies further
like cache locking or TLB pinning.
1)PPC:-
(MPC-860 at 48 MHz, 4 kB I-Cache and 4 kB D-Cache)
User mode:-
[EMAIL PROTECTED]:/mnt/out_xen/bin# ./latency -t0
== Sampling period: 1000000 us
== Test mode: periodic user-mode task
== All results in microseconds
warming up...
RTT| 00:00:01 (periodic user-mode task, 1000000 us
period, priority 99)
RTH|-----lat min|-----lat
avg|-----latmax|-overrun|----lat best|---lat worst
RTD| 167.000| 167.000| 167.000| 0|
167.000| 167.000
RTD| 176.000| 176.000| 176.000| 0|
167.000| 176.000
RTD| 168.000| 168.000| 168.000| 0|
167.000| 176.000
RTD| 171.000| 171.000| 171.000| 0|
167.000| 176.000
Kernel mode:-
[EMAIL PROTECTED]:/mnt/out_xen/bin# ./latency -t1
== Sampling period: 1000000 us
== Test mode: in-kernel periodic task
== All results in microseconds
warming up...
RTT| 00:00:00 (in-kernel periodic task, 1000000 us
period, priority 99)
RTH|-----lat min|-----lat
avg|-----latmax|-overrun|----lat best|---lat worst
RTD| 123.000| 123.000| 123.000| 0|
123.000| 123.000
RTD| 125.000| 125.000| 125.000| 0|
123.000| 125.000
RTD| 128.333| 128.333| 128.333| 0|
123.000| 128.333
RTD| 127.000| 127.000| 127.000| 0|
123.000| 128.333
Interrupt mode:-
[EMAIL PROTECTED]:/mnt/out_xen/bin# ./latency -t2
== Sampling period: 1000000 us
== Test mode: in-kernel timer handler
== All results in microseconds
warming up...
RTT| 00:00:01 (in-kernel timer handler, 1000000 us
period, priority 99)
RTH|-----lat min|-----lat
avg|-----latmax|-overrun|----lat best|---lat worst
RTD| 45.334| 45.334| 45.334| 0|
45.334| 45.334
RTD| 45.000| 45.000| 45.000| 0|
45.000| 45.334
RTD| 46.000| 46.000| 46.000| 0|
45.000| 46.000
RTD| 47.334| 47.334| 47.334| 0|
45.000| 47.334
RTD| 46.334| 46.334| 46.334| 0|
45.000| 47.334
On the MPC860, the latencies are mainly due code execution time as this
processor is very slow.
2)X86:-
(Pentium4, 3.06GHz, 1024 KB cache size)
User mode:-
Sampling period: 100 us
== Test mode: in-kernel periodic task
== 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| 3.807| 12.825| 21.565| 0|
3.807| 21.565
RTD| 3.796| 12.792| 21.483| 0|
3.796| 21.565
RTD| 3.770| 12.799| 21.501| 0|
3.770| 21.565
RTD| 3.578| 12.806| 20.890| 0|
3.578| 21.565
RTD| 3.755| 12.809| 21.486| 0|
3.578|
kernel mode:-
Sampling period: 100 us
== Test mode: in-kernel periodic task
== All results in microseconds
warming up...
RTT| 00:00:01 (in-kernel periodic task, 100 us
period, priority 99)
RTH|-----lat min|-----lat avg|-----lat
max|-overrun|----lat best|---lat worst
RTD| 2.381| 3.451| 19.620| 0|
2.381| 19.620
RTD| 2.332| 3.480| 19.930| 0|
2.332| 19.930
RTD| 2.382| 3.649| 19.609| 0|
2.332| 19.930
RTD| 2.323| 2.786| 14.351| 0|
2.323| 19.930
RTD| 2.375| 2.532| 5.519| 0|
2.323| 19.930
RTD| 2.332| 3.971| 19.617| 0|
2.323| 19.930
Interrupt mode:-
Sampling period: 100 us
== Test mode: in-kernel timer handler
== All results in microseconds
warming up...
RTT| 00:00:01 (in-kernel timer handler, 100 us
period, priority 99)
RTH|-----lat min|-----lat avg|-----lat
max|-overrun|----lat best|---lat worst
RTD| -1.563| 7.553| 15.736| 0|
-1.563| 15.736
RTD| -1.579| 7.558| 15.804| 0|
-1.579| 15.804
RTD| -1.584| 7.529| 16.167| 0|
-1.584| 16.167
RTD| -1.548| 7.553| 16.186| 0|
-1.584| 16.186
RTD| -1.585| 7.556| 16.275| 0|
-1.585| 16.275
Latencies are mainly due to cache refills on the P4. Have you already
put load onto your system? If not, worst case latencies will be even longer.
Wolfgang.
Thanks,
Poornima
--- Wolfgang Grandegger <[EMAIL PROTECTED]> wrote:
Hello,
poornima r wrote:
Hello,
Srry for not replying all these days...
(Was not in in station, may be too personal!!!!!)
About software emulation error:
4)Output of /proc/xenomai/faults after the illegal
instruction:-
[EMAIL PROTECTED]:/mnt/out_xen/bin# cat
/proc/xenomai/faults
TRAP CPU0
0: 0 (Data or instruction
access)
1: 0 (Alignment)
2: 0 (Altivec unavailable)
3: 0 (Program check exception)
4: 0 (Machine check exception)
5: 0 (Unknown)
6: 0 (Instruction breakpoint)
7: 0 (Run mode exception)
8: 0 (Single-step exception)
9: 0 (Non-recoverable exception)
10: 1 (Software emulation)
11: 0 (Debug)
12: 0 (SPE)
13: 0 (Altivec assist)
Hm, I see a software emulation exception which is
also the reason for
the illegal instructions. What toolchain do you
use?
The toolchain
should support software FP emulation.
1)I am using open source too chain with software
floating point emulation support.
(#ppc_8xx-gcc --v
/lib/gcc/powerpc/3.4.3/../../../../target_powerpc/usr/include/c++/3.4.3
--with-numa-policy=no --with-float=soft)
2)And the kernel is included with code to emulate
a
floating-point
unit, which will allow programs that
use floating-point
instructions to run
Kernel configuration
----CONFIG_MATH_EMULATION:y
If you build with "--with-float=soft" there is no
need for math
emulation in the kernel. Likely, there is something
wrong with your
tool-chain. Could you please try a known-to-work
tool-chain like the
ELDK v4.x from http://www.denx.de.
Wolfgang.
Thanks,
Poornima
--- Wolfgang Grandegger <[EMAIL PROTECTED]> wrote:
poornima r wrote:
Hi,
1)I am using open source kernel from Kernel.org,
but what is meant by vanilla kernel from
Kernel.org?
It's the kernel from kernel.org. This means that
the
Linux kernel 2.6.18
is running fine on your MPC860 platform as is?
Thanks for the info.
2)With sampling period of 500usec the system
simply
hangs without printing any results (./latenct
-p500)
OK.
3)cyclictest with -t1 option (without
IPIPE-tracer)
[EMAIL PROTECTED]:/mnt/out_xen/bin#
./cyclictest
-t1
2.04 0.50 0.17 8/27 174
T: 0 ( 0) P:99 I: 1000 C: 0 Min:
1000000
Act: 0 Avg: 0 Max:-1000000
Illegal instruction
4)Output of /proc/xenomai/faults after the
illegal
instruction:-
[EMAIL PROTECTED]:/mnt/out_xen/bin# cat
/proc/xenomai/faults
TRAP CPU0
0: 0 (Data or instruction
access)
1: 0 (Alignment)
2: 0 (Altivec unavailable)
3: 0 (Program check exception)
4: 0 (Machine check exception)
5: 0 (Unknown)
6: 0 (Instruction breakpoint)
7: 0 (Run mode exception)
8: 0 (Single-step exception)
9: 0 (Non-recoverable exception)
10: 1 (Software emulation)
11: 0 (Debug)
12: 0 (SPE)
13: 0 (Altivec assist)
Hm, I see a software emulation exception which is
also the reason for
the illegal instructions. What toolchain do you
use?
The toolchain
should support software FP emulation.
5)Running switchtest:-
[EMAIL PROTECTED]:/mnt/out_xen/bin#
./switchtest
-n
--The system hangs wihtout printing any results
Thanks,
Poornima
--- Wolfgang Grandegger <[EMAIL PROTECTED]>
wrote:
poornima r wrote:
Hi,
Thanks for the reply.
Linux version:linux-2.6.18
Xenomai: xenomai-2.3.0 (Stable version)
adeos patch:
adeos-ipipe-2.6.18-ppc-1.5-01.patch
OK, I'm curious, did you use the vanilla kernel
from
kernel.org?
More comments below.
The tests were run as follows:
1)The sampling period in the code for latency
and
switchbench was changed to 1000000000ns(to
remove
overrun error)
2)switchtest was run with -n5 option
3)cyclictest was run with -t5 option(5
threads
were created.)
4)cyclictest was terminated with Illegal
instruction
(after creating 5 threads) with IPIPE tracer
enabled.
These were the results without I-PIPE Tracer
option:
(All the tests were run without any load)
1)LATENCY TEST:-
User mode:-
/mnt/out_xen/bin# ./latency -t0
== Sampling period: 1000000 us
== Test mode: periodic user-mode task
== All results in microseconds
warming up...
RTT| 00:00:01 (periodic user-mode task,
1000000
us
period, priority 99)
RTH|-----lat min|-----lat avg|-----lat
max|-overrun|----lat best|---lat worst
RTD| 167.000| 167.000| 167.000|
0|
167.000| 167.000
RTD| 176.000| 176.000| 176.000|
0|
167.000| 176.000
RTD| 168.000| 168.000| 168.000|
0|
167.000| 176.000
=== message truncated ===
____________________________________________________________________________________
Get your own web address.
Have a HUGE year through Yahoo! Small Business.
http://smallbusiness.yahoo.com/domains/?p=BESTDEAL
_______________________________________________
Adeos-main mailing list
[email protected]
https://mail.gna.org/listinfo/adeos-main
_______________________________________________
Adeos-main mailing list
[email protected]
https://mail.gna.org/listinfo/adeos-main
