I seem to remember discussion of anticipatory vs deadline scheduler in 2.6.
Here is what Andrew Morton (I think) says:
"The deadline scheduler has two additional scheduling queues that were not
available to the 2.4 IO scheduler. The two new queues are a FIFO read queue
and a FIFO write queue. This new multi-queue method allows for greater
interactivity by giving the read requests a better deadline than write
requests, thus ensuring that applications rarely will be delayed by read
requests.
Deadline scheduling is best suited for database servers and high disk
performance systems. Morton has experienced up to 15 percent increases on
database loads while using deadline scheduling."
http://story.news.yahoo.com/news?tmpl=story&cid=75&e=2&u=/nf/20040405/tc_nf/23603
Nothing very in-depth in the story.
--
Richard Huxton
Archonet Ltd
