Messages in this thread | | | Date | Sat, 23 Aug 2003 19:18:53 +1000 | From | Nick Piggin <> | Subject | Re: [PATCH]O18.1int |
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Thomas Schlichter wrote:
>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... > >
Hi I don't know what is preferred on lkml, but I dislike mixing booleans and integer arithmetic.
if (!LOW_CREDIT(prev)) prev->interactive_credit--;
Easier to read IMO.
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