Re: [PATCH v4] sched: automated per session task groups

Paul Turner
2010-12-07T11:33:32Z

Desktop hardware came in today and I can now reproduce the issues
Mike's been seeing; tuning in progress.

On Sat, Dec 4, 2010 at 9:11 PM, Paul Turner <pjt@google.com> wrote:
> On Sat, Dec 4, 2010 at 3:55 PM, James Courtier-Dutton
> <james.dutton@gmail.com> wrote:
>> On 3 December 2010 05:11, Paul Turner <pjt@google.com> wrote:
>>>
>>> I actually don't have a desktop setup handy to test "interactivity" (sad but
>>> true -- working on grabbing one).  But it looks better on under synthetic
>>> load.
>>>
>>
>> What tools are actually used to test "interactivity" ?
>> I posted a tool to the list some time ago, but I don't think anyone noticed.
>> My tool is very simple.
>> When you hold a key down, it should repeat. It should repeat at a
>> constant predictable interval.
>> So, my tool just waits for key presses and times when each one occurred.
>> The tester simply presses a key and holds it down.
>> If the time between each key press is constant, it indicates good
>> "interactivity". If the time between each key press varies a lot, it
>> indicates bad "interactivity".
>> You can reliably test if one kernel is better than the next using
>> actual measurable figures.
>>
>> Kind Regards
>>
>> James
>>
>
> Could you drop me a pointer?  I can certainly give it a try.  It would
> be extra useful if it included any histogram functionality.
>
> I've been using a combination of various synthetic wakeup and load
> scripts and measuring the received bandwidth / wakeup latency.
>
> They have not succeeded in reproducing the starvation or poor latency
> observed by Mike above however.  (Although I've pulled a box to try
> reproducing his exact conditions [ e.g. user environment ] on Monday).
>