Re: Re[2]: [Devil-linux-develop] RTOS patch for DL

[Heiko Z. <he...@zu...>]

On Thu, July 28, 2005 01:51, Serge Leschinsky wrote:
> Dear Heiko,
>
>
> Wednesday, July 27, 2005, 9:21:12 PM, you wrote:
>
>
>>>> Without Perf patch    |  With Perf patch
>>>> max:                   93.7898s      |  21.2820s
>>>> approx.  95 percentile: 61.2178s      |  18.1917s | Threads fairness:
>>>> |
>>>> distributin:            45.45/79.44   |  100.00/100.00
>>>> execution:              42.06/78.00   |  99.62/99.93
>>>>
>>>>
>>>
>>> The most interesting result is "approx.  95 percentile:", i.e. the
>>> most evident time of thread execute.
>
> HZ> Are you sure you have the columns right? Right now it looks to me
> like HZ> without the perf patch it's faster.
> Yes, you are right. Without rtos patches kernel a bit faster, BUT
> patched kernel more "threads fairness". The time of system reaction greatly
> grows in the heavy loaded system, but with rtos patch time of reaction is
> approximately constant. It's a quite logical - scheduler with taking
> "priority" into consideration ( aka intellectual scheduler
> ) is slower as simple scheduler because it must check more conditions
> before switch task. But take a closer look on the test results - without
> patch max time of thread execution is 93s, patched - only 21s. As I said
> in my previous message, the most interesting result is "approx.  95
> percentile": with
> the probability of 95% the time of test thread execution is 18s in the
> patched system and 61s in the doesn't patched system. It's a serious
> difference, I suppose, especially for applications with strong time
> dependence (VoIP for a example).
>
> Some information abt RTOS and these patches:
> http://www.linuxdevices.com/articles/AT8906594941.html

OK this sounds like it's worth including it.
Does it only work without the grsec patch?
If yes, maybe Bruce wants to include it for the server version?

-- 

Regards
  Heiko Zuerker
  http://www.devil-linux.org