Messages in this thread | | | Date | Tue, 4 Apr 2006 17:02:41 -0400 | From | "Vishal Patil" <> | Subject | Re: CSCAN I/O scheduler for 2.6.10 kernel |
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In that case it would be a normal elevator algorithm and that has a possiblity of starving the requests at one end of the disk.
- Vishal
On 4/4/06, Bill Davidsen <davidsen@tmr.com> wrote: > Vishal Patil wrote: > > Maintain two queues which will be sorted in ascending order using Red > > Black Trees. When a disk request arrives and if the block number it > > refers to is greater than the block number of the current request > > being served add (merge) it to the first sorted queue or else add > > (merge) it to the second sorted queue. Keep on servicing the requests > > from the first request queue until it is empty after which switch over > > to the second queue and now reverse the roles of the two queues. > > Simple and Sweet. Many thanks for the awesome block I/O layer in the > > 2.6 kernel. > > > Why both queues sorting in ascending order? I would think that one > should be in descending order, which would reduce the seek distance > between the last i/o on one queue and the first on the next. > > -- > -bill davidsen (davidsen@tmr.com) > "The secret to procrastination is to put things off until the > last possible moment - but no longer" -me >
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