Divyesh Shah 3a9a3f6cc5 cfq-iosched: Allow RT requests to pre-empt ongoing BE timeslice ...

This patch adds the ability to pre-empt an ongoing BE timeslice when a RT
request is waiting for the current timeslice to complete. This reduces the
wait time to disk for RT requests from an upper bound of 4 (current value
of cfq_quantum) to 1 disk request.

Applied Jens' suggeested changes to avoid the rb lookup and use !cfq_class_rt()
and retested.

Latency(secs) for the RT task when doing sequential reads from 10G file.
                       | only RT | RT + BE | RT + BE + this patch
small (512 byte) reads | 143     | 163     | 145
large (1Mb) reads      | 142     | 158     | 146

Signed-off-by: Divyesh Shah <dpshah@google.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

2009-01-30 12:47:33 +01:00

..

as-iosched.c

block: get rid of elevator_t typedef

2008-12-29 08:29:50 +01:00

blk-barrier.c

block: Fix documentation for blkdev_issue_flush()

2009-01-30 12:34:37 +01:00

blk-core.c

block: add sysfs file for controlling io stats accounting

2009-01-30 12:34:38 +01:00

blk-exec.c

Add some block/ source files to the kernel-api docbook. Fix kernel-doc notation in them as needed. Fix changed function parameter names. Fix typos/spellos. In comments, change REQ_SPECIAL to REQ_TYPE_SPECIAL and REQ_BLOCK_PC to REQ_TYPE_BLOCK_PC.

2008-10-09 08:56:03 +02:00

blk-integrity.c

block: Allow empty integrity profile

2009-01-30 12:34:36 +01:00

blk-ioc.c

cfq-iosched: fix RCU race in the cfq io_context destructor handling

2008-05-07 09:28:57 +02:00

blk-map.c

[SCSI] block: make blk_rq_map_user take a NULL user-space buffer for WRITE

2009-01-02 11:10:35 -06:00

blk-merge.c

block: remove unused ll_new_mergeable()

2008-11-06 08:41:55 +01:00

blk-settings.c

block: use min_not_zero in blk_queue_stack_limits

2008-12-29 08:29:51 +01:00

blk-softirq.c

block: make blk_softirq_init() static

2008-12-29 08:29:51 +01:00

blk-sysfs.c

block: add sysfs file for controlling io stats accounting

2009-01-30 12:34:38 +01:00

blk-tag.c

block/blk-tag.c: cleanup kernel-doc

2008-12-29 08:28:43 +01:00

blk-timeout.c

block: leave the request timeout timer running even on an empty list

2008-12-29 08:28:42 +01:00

blk.h

cpumask: Replace cpu_coregroup_map with cpu_coregroup_mask

2008-12-26 22:23:43 +10:30

blktrace.c

block: get rid of the manual directory counting in blktrace

2009-01-30 12:34:36 +01:00

bsg.c

block: struct device - replace bus_id with dev_name(), dev_set_name()

2009-01-06 10:44:43 -08:00

cfq-iosched.c

cfq-iosched: Allow RT requests to pre-empt ongoing BE timeslice

2009-01-30 12:47:33 +01:00

cmd-filter.c

[PATCH] introduce fmode_t, do annotations

2008-10-21 07:47:06 -04:00

compat_ioctl.c

block: don't take lock on changing ra_pages

2008-12-29 08:28:43 +01:00

deadline-iosched.c

block: get rid of elevator_t typedef

2008-12-29 08:29:50 +01:00

elevator.c

block: get rid of elevator_t typedef

2008-12-29 08:29:50 +01:00

genhd.c

block: struct device - replace bus_id with dev_name(), dev_set_name()

2009-01-06 10:44:43 -08:00

ioctl.c

block: don't take lock on changing ra_pages

2008-12-29 08:28:43 +01:00

Kconfig

block: Add Kconfig help which notes that ext4 needs CONFIG_LBD

2009-01-06 15:16:33 -05:00

Kconfig.iosched

update I/O sched Kconfig help texts - CFQ is now default, not AS.

2007-02-17 20:08:22 +01:00

Makefile

block: unify request timeout handling

2008-10-09 08:56:13 +02:00

noop-iosched.c

block: get rid of elevator_t typedef

2008-12-29 08:29:50 +01:00

scsi_ioctl.c

scsi-ioctl: use clock_t <> jiffies

2008-12-29 08:28:42 +01:00