Beagleboard xM - Bogomips are very low

Beagleboard xM - Bogomips are very low

[Guillaume Gardet]

Hi,

On a Beagleboard xM rev. B, I noticed that vanilla kernel 3.4.6 have the folowing bogomips for 300MHz and 800 MHz operations: 262.08 and 700.57.

With kernel 3.7.10, I have : 175.65 and 467.41 bogompis.

Any idea why bogomips are so low now?

Guillaume

Re: Beagleboard xM - Bogomips are very low

[Nishanth Menon]

On 16:17-20130319, Guillaume Gardet wrote:
> Hi,
> 
> On a Beagleboard xM rev. B, I noticed that vanilla kernel 3.4.6 have the folowing bogomips for 300MHz and 800 MHz operations: 262.08 and 700.57.
> 
> With kernel 3.7.10, I have : 175.65 and 467.41 bogompis.
> 
> Any idea why bogomips are so low now?
using my DTS cpufreq series (which I am about to post to linux-omap):
https://github.com/nmenon/linux-2.6-playground/commits/push/cpufreq-cpu0-omap-all-v2
and a test script:
http://pastebin.com/zrr8ptge

I See (3.9-rc3):
http://pastebin.com/4JCV3dnX

bogomips@ boot:
BogoMIPS        : 395.67
Boot scaling frequency =600000
TESTING for 1 seconds at 300000
current scaling frequency(for 300000) =300000
bogomips@ frequency 300000:
BogoMIPS        : 197.83
TESTING for 1 seconds at 600000
current scaling frequency(for 600000) =600000
bogomips@ frequency 600000:
BogoMIPS        : 395.67
TESTING for 1 seconds at 800000
current scaling frequency(for 800000) =800000
bogomips@ frequency 800000:
BogoMIPS        : 527.56
-- 
Regards,
Nishanth Menon

Re: Beagleboard xM - Bogomips are very low

[Frank Agius]

On 3/19/2013 11:17 AM, Guillaume Gardet wrote:
> Hi,
>
> On a Beagleboard xM rev. B, I noticed that vanilla kernel 3.4.6 have the
> folowing bogomips for 300MHz and 800 MHz operations: 262.08 and 700.57.
>
> With kernel 3.7.10, I have : 175.65 and 467.41 bogompis.
>
> Any idea why bogomips are so low now?
>

I believe this is the reason for the BogoMIPS change:

http://www.spinics.net/lists/arm-kernel/msg221672.html

It looks like BogoMIPS reporting changed because of the delay routine 
patch introduced in 3.6.  So the change in BogoMIPS is real, but should 
not be a concern.

frank agius

> Guillaume
>
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Re: Beagleboard xM - Bogomips are very low

[Guillaume Gardet]

Le 20/03/2013 13:48, Frank Agius a écrit :
> On 3/19/2013 11:17 AM, Guillaume Gardet wrote:
>> Hi,
>>
>> On a Beagleboard xM rev. B, I noticed that vanilla kernel 3.4.6 have the
>> folowing bogomips for 300MHz and 800 MHz operations: 262.08 and 700.57.
>>
>> With kernel 3.7.10, I have : 175.65 and 467.41 bogompis.
>>
>> Any idea why bogomips are so low now?
>>
>
> I believe this is the reason for the BogoMIPS change:
>
> http://www.spinics.net/lists/arm-kernel/msg221672.html
>
> It looks like BogoMIPS reporting changed because of the delay routine patch introduced in 3.6.  So the change in BogoMIPS is real, but should not be a concern.

Thanks for the pointer. So, it should not affect performances.
I will try to bench it, to be sure there is no hidden problem.

Thanks.


Guillaume


>
> frank agius
>
>> Guillaume
>>
>> -- 
>> To unsubscribe from this list: send the line "unsubscribe linux-omap" in
>> the body of a message to majordomo@vger.kernel.org
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>>
>
>

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