Messages in this thread | | | From | Thomas Schlichter <> | Subject | Re: [PATCH]O18.1int | Date | Sat, 23 Aug 2003 11:08:46 +0200 |
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On Saturday 23 August 2003 07:55, Con Kolivas wrote: > Some high credit tasks were being missed due to their prolonged cpu burn at > startup flagging them as low credit tasks. > > Low credit tasks can now recover to become high credit. > > Con
Hi Con!
First of all... Your interactive scheduler work is GREAT! I really like it...!
Now I tried to unterstand what exacly the latest patch does, and as far as I can see the first and the third hunk just delete respectively expand the macro VARYING_CREDIT(p). But the second hunk helps processes to get some interactive_credit until they become a HIGH_CREDIT task. This looks reasonable to me...
So, now I wanted to know how a task may lose its interactive_credit again... The only code I saw doing this is exaclty the third hunk of your patch. But if a process is a HIGH_CREDIT task it can never lose its interactive_credit again. Is that intented?
I think the third hunk should look like following: @@ -1548,7 +1545,7 @@ switch_tasks: prev->sleep_avg -= run_time; if ((long)prev->sleep_avg <= 0){ prev->sleep_avg = 0; - prev->interactive_credit -= VARYING_CREDIT(prev); + prev->interactive_credit -= !(LOW_CREDIT(prev)); } prev->timestamp = now;
As an additional idea I think interactive_credit should be allowed to be a bit bigger than MAX_SLEEP_AVG and a bit lower than -MAX_SLEEP_AVG. This would make LOW_CREDIT processes stay LOW_CREDIT even if they do some sleep and HIGH_CREDIT processes star HIGH_CREDIT even if they do some computing...
But of course I may completely miss something...
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