Re: [PATCH] O6int for interactivity

[Wade <neroz@ii.net>]

Con Kolivas wrote:
> Quoting Davide Libenzi <davidel@xmailserver.org>:
> 
> 
>>On Thu, 17 Jul 2003, Con Kolivas wrote:
>>
>>
>>>O*int patches trying to improve the interactivity of the 2.5/6 scheduler
>>
>>for
>>
>>>desktops. It appears possible to do this without moving to nanosecond
>>>resolution.
>>>
>>>This one makes a massive difference... Please test this to death.
>>>
>>>Changes:
>>>The big change is in the way sleep_avg is incremented. Any amount of sleep
>>>will now raise you by at least one priority with each wakeup. This causes
>>>massive differences to startup time, extremely rapid conversion to
>>
>>interactive
>>
>>>state, and recovery from non-interactive state rapidly as well (prevents X
>>>stalling after thrashing around under high loads for many seconds).
>>>
>>>The sleep buffer was dropped to just 10ms. This has the effect of causing
>>
>>mild
>>
>>>round robinning of very interactive tasks if they run for more than 10ms.
>>
>>The
>>
>>>requeuing was changed from (unlikely()) to an ordinary if.. branch as this
>>>will be hit much more now.
>>
>>Con, I'll make a few notes on the code and a final comment.
>>
>>
>>
>>
>>>-#define MAX_BONUS		((MAX_USER_PRIO - MAX_RT_PRIO) * 
> 
> PRIO_BONUS_RATIO /
> 
>>100)
>>
>>>+#define MAX_BONUS		(40 * PRIO_BONUS_RATIO / 100)
>>
>>Why did you bolt in the 40 value ? It really comes from (MAX_USER_PRIO -
>>MAX_RT_PRIO)
>>and you will have another place to change if the number of slots will
>>change. If you want to clarify better, stick a comment.
> 
> 
> Granted. Will revert. If you don't understand it you shouldn't be fiddling with 
> it I agree.
> 
> 
>>
>>
>>>+			p->sleep_avg = (p->sleep_avg * MAX_BONUS / runtime + 1) 
> 
> * runtime /
> 
>>MAX_BONUS;
>>
>>I don't have the full code so I cannot see what "runtime" is, but if
>>"runtime" is the time the task ran, this is :
>>
>>p->sleep_avg ~= p->sleep_avg + runtime / MAX_BONUS;
>>
>>(in any case a non-decreasing function of "runtime" )
>>Are you sure you want to reward tasks that actually ran more ?
> 
> 
> 
> That was the bug. Runtime was supposed to be limited to MAX_SLEEP_AVG. Fix will 
> be posted very soon.

Should any harm come from running 06int without the phantom patch
mentioned?