linux/block
Jens Axboe d9e7620e60 cfq-iosched: rework the whole round-robin list concept
Drawing on some inspiration from the CFS CPU scheduler design, overhaul
the pending cfq_queue concept list management. Currently CFQ uses a
doubly linked list per priority level for sorting and service uses.
Kill those lists and maintain an rbtree of cfq_queue's, sorted by when
to service them.

This unfortunately means that the ionice levels aren't as strong
anymore, will work on improving those later. We only scale the slice
time now, not the number of times we service. This means that latency
is better (for all priority levels), but that the distinction between
the highest and lower levels aren't as big.

The diffstat speaks for itself.

 cfq-iosched.c |  363 +++++++++++++++++---------------------------------
 1 file changed, 125 insertions(+), 238 deletions(-)

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-04-30 09:01:21 +02:00
..
as-iosched.c [PATCH] Allow as-iosched to be unloaded 2006-12-13 13:25:18 +01:00
blktrace.c [PATCH] mark struct file_operations const 3 2007-02-12 09:48:45 -08:00
cfq-iosched.c cfq-iosched: rework the whole round-robin list concept 2007-04-30 09:01:21 +02:00
deadline-iosched.c [BLOCK] Cleanup unused variable passing 2006-12-01 10:42:33 +01:00
elevator.c make elv_register() output atomic 2007-03-27 08:53:04 +02:00
genhd.c [PATCH] remove protection of LANANA-reserved majors 2007-04-04 21:12:47 -07:00
ioctl.c [PATCH] lockdep: annotate BLKPG_DEL_PARTITION 2007-02-20 17:10:16 -08:00
Kconfig [PATCH] Centralise definitions of sector_t and blkcnt_t 2006-12-04 19:41:15 -08:00
Kconfig.iosched update I/O sched Kconfig help texts - CFQ is now default, not AS. 2007-02-17 20:08:22 +01:00
ll_rw_blk.c block: blk_max_pfn is somtimes wrong 2007-03-27 08:52:47 +02:00
Makefile [PATCH] BLOCK: Make it possible to disable the block layer [try #6] 2006-09-30 20:52:31 +02:00
noop-iosched.c [BLOCK] Cleanup unused variable passing 2006-12-01 10:42:33 +01:00
scsi_ioctl.c [PATCH] Fix SG_IO timeout jiffy conversion 2007-01-29 20:32:03 -08:00