[16/23] io-controller: deadline changes for hierarchical fair queuing

Commit Message

Vivek Goyal Aug. 28, 2009, 9:31 p.m. UTC

This patch changes deadline to use queue scheduling code from elevator layer.
One can go back to old deadline by selecting CONFIG_IOSCHED_DEADLINE_HIER.

Signed-off-by: Nauman Rafique <[e-mail]>
Signed-off-by: Vivek Goyal <[e-mail]>
---
 block/Kconfig.iosched    |   11 +++++++++++
 block/deadline-iosched.c |    9 +++++++++
 2 files changed, 20 insertions(+), 0 deletions(-)

Comments

Rik van Riel Aug. 31, 2009, 3:13 a.m. UTC | #1

Vivek Goyal wrote:
> This patch changes deadline to use queue scheduling code from elevator layer.
> One can go back to old deadline by selecting CONFIG_IOSCHED_DEADLINE_HIER.
                                     ^ deselecting ?

> Signed-off-by: Nauman Rafique <[e-mail]>
> Signed-off-by: Vivek Goyal <[e-mail]>

Acked-by: Rik van Riel <[e-mail]>

Vivek Goyal Aug. 31, 2009, 1:46 p.m. UTC | #2

On Sun, Aug 30, 2009 at 11:13:23PM -0400, Rik van Riel wrote:
> Vivek Goyal wrote:
>> This patch changes deadline to use queue scheduling code from elevator layer.
>> One can go back to old deadline by selecting CONFIG_IOSCHED_DEADLINE_HIER.
>                                     ^ deselecting ?
>

Yes. Its a typo. Should be "deselecting". Will fix the comment.

Thanks
Vivek

>> Signed-off-by: Nauman Rafique <[e-mail]>
>> Signed-off-by: Vivek Goyal <[e-mail]>
>
> Acked-by: Rik van Riel <[e-mail]>
>
> -- 
> All rights reversed.

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Patch

diff --git a/block/Kconfig.iosched b/block/Kconfig.iosched
index 28cd500..cc87c87 100644
--- a/block/Kconfig.iosched
+++ b/block/Kconfig.iosched
@@ -55,6 +55,17 @@  config IOSCHED_DEADLINE
 	  a disk at any one time, its behaviour is almost identical to the
 	  anticipatory I/O scheduler and so is a good choice.
 
+config IOSCHED_DEADLINE_HIER
+	bool "Deadline Hierarchical Scheduling support"
+	depends on IOSCHED_DEADLINE && CGROUPS
+	select ELV_FAIR_QUEUING
+	select GROUP_IOSCHED
+	default n
+	---help---
+	  Enable hierarhical scheduling in deadline. In this mode deadline keeps
+	  one IO queue per cgroup instead of a global queue. Elevator
+	  fair queuing logic ensures fairness among various queues.
+
 config IOSCHED_CFQ
 	tristate "CFQ I/O scheduler"
 	select ELV_FAIR_QUEUING
diff --git a/block/deadline-iosched.c b/block/deadline-iosched.c
index 6e69ea3..e5bc823 100644
--- a/block/deadline-iosched.c
+++ b/block/deadline-iosched.c
@@ -13,6 +13,7 @@ 
 #include <linux/init.h>
 #include <linux/compiler.h>
 #include <linux/rbtree.h>
+#include "elevator-fq.h"
 
 /*
  * See Documentation/block/deadline-iosched.txt
@@ -461,6 +462,11 @@  static struct elv_fs_entry deadline_attrs[] = {
 	DD_ATTR(writes_starved),
 	DD_ATTR(front_merges),
 	DD_ATTR(fifo_batch),
+#ifdef CONFIG_IOSCHED_DEADLINE_HIER
+	ELV_ATTR(fairness),
+	ELV_ATTR(slice_sync),
+	ELV_ATTR(group_idle),
+#endif
 	__ATTR_NULL
 };
 
@@ -478,6 +484,9 @@  static struct elevator_type iosched_deadline = {
 		.elevator_alloc_sched_queue_fn = deadline_alloc_deadline_queue,
 		.elevator_free_sched_queue_fn = deadline_free_deadline_queue,
 	},
+#ifdef CONFIG_IOSCHED_DEADLINE_HIER
+	.elevator_features = ELV_IOSCHED_NEED_FQ | ELV_IOSCHED_SINGLE_IOQ,
+#endif
 	.elevator_attrs = deadline_attrs,
 	.elevator_name = "deadline",
 	.elevator_owner = THIS_MODULE,