eLua Development

Timing

Posted by jbsnyder on
URL: http://elua-development.15.s1.nabble.com/Timing-tp2422112p2422141.html

That's true. You would want to normalize the clock rates between
different platforms as well.

Also, this is more just to get a sense for what the minimum timer
difference and whether that seems to vary between platforms.

If you want to try a benchmark, I modified the version of the Seive of
Eratosthenes (finds primes) that appears on the Lua listserv from some
time ago (http://lua-users.org/lists/lua-l/1999-07/msg00087.html) to
use timing on eLua, and to only search up to 2000 because otherwise
you run out of memory in 64k of SRAM:

function sieve(n)
x = {}
iter = 0
repeat
x[1] = 0
i = 2
repeat
x[i] = 1
i = i + 1
until i > n
p = 2
while(p * p <= n) do
j = p
while(j <= n) do
x[j] = 0
j = j + p
end
repeat
p = p + 1
until x[p] == 1
end
iter = iter + 1
until iter == 101
end

print("Sieve of Eratosthenes - Lua Benchmark test")
print("Start testing .....")
start = tmr.start(0)
sieve(2000)
stop = tmr.read(0)
print("Done!")
print("Total Time (sec): "..tmr.diff(0,start,stop)/1000000)
print("System Clock (MHz): "..cpu.clock()/1000000)
print("System CPU: "..pd.cpu())

If anyone else wants to try this game, I get the following:
Total Time (sec): 17.395011
System Clock (MHz): 50
System CPU: LM3S6965

If I went any higher, it seemed to run out of memory for me :-)

On Feb 18, 2009, at 4:04 PM, Bogdan Marinescu wrote:

> This won't be as relevant, different platforms have different
> initial clock speeds. The clock speed must first be set to its
> maximum, then the script must be run, otherwise the results won't be
> meaningful. It just happens that on LM3S the timer frequency is
> equal to the clock speed.
>
> Best,
> Bogdan
>
> On Wed, Feb 18, 2009 at 11:46 PM, Dado Sutter <dadosutter at gmail.com>
> wrote:
> Fernando, could you run this simple script on the EK-1100 and report
> AVR32 performance ?
>
> We have a MOD711, with an ST711 (ARM7) too but after strugling (and
> achieving ! :) to make it work on Linux, OpenOCD now refuses to
> flash our kit :( :( :( :(
>
> Best
> Dado
>
>
>
>
>
>
>
>
> On Wed, Feb 18, 2009 at 17:15, James Snyder
> <jbsnyder at fanplastic.org> wrote:
> OK. At least I know my compiler isn't messed up :-)
>
> I'm curious now though whether similarly clocked ARM7 vs AVR vs
> Cortex-M3 (ARM Thumb2) vs etc.. do for these types of tests.
>
> -jsnyder
>
> On Feb 18, 2009, at 10:24 AM, Dado Sutter wrote:
>
>> Hello,
>>
>> On Wed, Feb 18, 2009 at 10:59, James Snyder
>> <jbsnyder at fanplastic.org> wrote:
>>
>> > On Wed, Feb 18, 2009 at 02:19, James Snyder <jbsnyder at fanplastic.org
>> > wrote:
>> >
>> So, one of the things I've been doing recently is tracking timing
>> data for adcscope.lua when running it. I've found certain things
>> that increase or decrease the amount of time spent getting samples,
>> but I hadn't actually checked what the bare minimum time would be
>> for a dry loop like the following:
>> >
>> > term.clrscr()
>> >
>> > while 1 do
>> > t1 = tmr.start(0)
>> > t2 = tmr.read(0)
>> > dtime = tmr.diff(0,t2,t1)
>> > term.gotoxy(1,1)
>> > term.putstr(string.format("Time (us): %06d",dtime))
>> > end
>> >
>> > For LM3S6965, I get 79 us. Is this correct?
>>
>> 79us exactly in my EK-LM3S8962 too.
>> (And I've figured out that you have disabled XMODEM Xfer on your
>> build :)
>>
>> Abra?osssssssssss
>> Dado
>>
>> _______________________________________________
>> Elua-dev mailing list
>> Elua-dev at lists.berlios.de
>> https://lists.berlios.de/mailman/listinfo/elua-dev
>
> --
> James Snyder
> Biomedical Engineering
> Northwestern University
> jbsnyder at fanplastic.org
> http://fanplastic.org/key.txt
> ph: (847) 644-2322
>
>
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>
>
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>
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--
James Snyder
Biomedical Engineering
Northwestern University
jbsnyder at fanplastic.org
http://fanplastic.org/key.txt
ph: (847) 644-2322

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