Author nirai
Recipients DazWorrall, aconrad, alex, brian.curtin, carljm, coderanger, cool-RR, dabeaz, djc, durin42, eric.araujo, eric.smith, flox, jcea, jhylton, karld, kevinwatters, konryd, larry, loewis, mahmoudimus, movement, neologix, nirai, pitrou, rcohen, rh0dium, salgado, tarek, thouis
Date 2010-04-17.17:47:48
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Message-id <1271526471.2.0.982888737553.issue7946@psf.upfronthosting.co.za>
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Content
> the scheduling function bfs_find_task returns the first task that 
> has an expired deadline. since an expired deadline probably means 
> that the scheduler hasn't run for a while, it might be worth it to 
> look for the thread with the oldest deadline and serve it first, 
> instead of stopping at the first one

This is by design of BFS as I understand it. Next thread to run is either first expired or oldest deadline:

http://ck.kolivas.org/patches/bfs/sched-BFS.txt
"Once a task is descheduled, it is put back on the queue, and an
O(n) lookup of all queued-but-not-running tasks is done to determine which has
the earliest deadline and that task is chosen to receive CPU next. The one
caveat to this is that if a deadline has already passed (jiffies is greater
than the deadline), the tasks are chosen in FIFO (first in first out) order as
the deadlines are old and their absolute value becomes decreasingly relevant
apart from being a flag that they have been asleep and deserve CPU time ahead
of all later deadlines."
History
Date User Action Args
2010-04-17 17:47:51niraisetrecipients: + nirai, loewis, jhylton, jcea, pitrou, movement, larry, eric.smith, kevinwatters, tarek, djc, karld, carljm, coderanger, durin42, eric.araujo, alex, konryd, brian.curtin, flox, DazWorrall, salgado, cool-RR, rh0dium, rcohen, dabeaz, mahmoudimus, aconrad, neologix, thouis
2010-04-17 17:47:51niraisetmessageid: <1271526471.2.0.982888737553.issue7946@psf.upfronthosting.co.za>
2010-04-17 17:47:49nirailinkissue7946 messages
2010-04-17 17:47:48niraicreate