Re: [Xenomai] Performance impact after switching from 2.6.2.1 to 2.6.4

[Wolfgang Netbal <wolfgang.netbal@sigmatek.at>]

Am 2016-06-28 um 14:01 schrieb Gilles Chanteperdrix:
> On Tue, Jun 28, 2016 at 01:55:27PM +0200, Wolfgang Netbal wrote:
>>
>> Am 2016-06-28 um 12:39 schrieb Gilles Chanteperdrix:
>>> On Tue, Jun 28, 2016 at 12:31:42PM +0200, Wolfgang Netbal wrote:
>>>> Am 2016-06-28 um 12:19 schrieb Gilles Chanteperdrix:
>>>> min: 10, max: 677, avg: 10.5048 -> 0.0265273 us
>>>>
>>>> Here are the output for Kernel 3.0.43 and Xenomai 2.6.2.1
>>>>
>>>> #> ./tsc
>>>> min: 10, max: 667, avg: 11.5755 -> 0.029231 us
>>> Ok. So, first it confirms that the two configurations are running
>>> the processor at the same frequency. But we seem to see a pattern,
>>> the maxima in the case of the new kernel seems consistently higher.
>>> Which would suggest that there is some difference in the cache. What
>>> is the status of the two configurations with regard to the L2 cache
>>> write allocate policy?
>> Do you mean the configuration we checked in this request
>> https://xenomai.org/pipermail/xenomai/2016-June/036390.html
> This answer is based on a kernel message, which may happen before
> or after the I-pipe patch has changed the value passed to the
> register, so, essentially, it is useless. I would not call that
> checking the L2 cache configuration differences.
>
I readed the values from the auxiliary control register,
when the system is up and running.
I get the same values like I see in the Kernel log.

Kernel 3.10.53 [0xa02104]=0x32c50000
Kernel 3.0.43    [0xa02104]=0x2850000