Re: High latencies with linux-2.6.25.4-rt6 on MPC5200

[Wolfgang Grandegger <wg@grandegger.com>]

Hi Fu,

Luotao Fu wrote:
> Hi Wolfgang,
> I finally found some time and did some tests with your config file and the shiny
> new 2.6.25.8-rt7
> 
> On Thu, Jun 19, 2008 at 04:04:10PM +0200, Wolfgang Grandegger wrote:
>> Hi Fu,
>>
>> Luotao Fu wrote:
>> Keep in mind that I'm running Linux on a rootfs mounted via NFS.
> 
> I have exactly the same test configuration here.

Interesting, I'm able to trigger latencies up to 600 us with the command

   "# while ls; do ls /bin; done"

in a telnet session, but it takes a while.

> Again everything looks just fine to me. Depending on which debugging Option are
> turned on my max. results pended between 70 and 350 us. However I could not
> produce any peak worst case values, which are so far away from the average like
> in your case.

Could you send me your .config file? And what version of cyclictest are 
you using?

> Have you tried the new -rt patch on your board? Still any strange results?

I will give it a try next week.

Wolfgang.