[lkml]   [2009]   [Aug]   [31]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH 17/23] io-controller: anticipatory changes for hierarchical fair queuing
Vivek Goyal wrote:
> This patch changes anticipatory scheduler to use queue scheduling code from
> elevator layer. One can go back to old as by deselecting
> other cgroup created, AS behavior should remain the same as old.
> o AS is a single queue ioschduler, that means there is one AS queue per group.
> o common layer code select the queue to dispatch from based on fairness, and
> then AS code selects the request with-in group.
> o AS runs reads and writes batches with-in group. So common layer runs timed
> group queues and with-in group time, AS runs timed batches of reads and
> writes.
> o Note: Previously AS write batch length was adjusted synamically whenever
> a W->R batch data direction took place and when first request from the
> read batch completed.
> Now write batch updation takes place when last request from the write
> batch has finished during W->R transition.
> o AS runs its own anticipation logic to anticipate on reads. common layer also
> does the anticipation on the group if think time of the group is with-in
> slice_idle.
> o Introduced few debugging messages in AS.
> Signed-off-by: Nauman Rafique <>
> Signed-off-by: Vivek Goyal <>

Acked-by: Rik van Riel <>

 \ /
  Last update: 2009-08-31 19:25    [W:0.403 / U:2.180 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site