[PATCH 12/20] io-controller: deadline changes for hierarchical fair queuing

Vivek Goyal
2009-06-19T20:43:14Z

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 <nauman@google.com>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
---
block/Kconfig.iosched | 11 +++++++++++
block/deadline-iosched.c | 8 ++++++++
2 files changed, 19 insertions(+), 0 deletions(-)

diff --git a/block/Kconfig.iosched b/block/Kconfig.iosched
index 9da6657..3a9e7d7 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 3a195ce..bae8e44 100644
--- a/block/deadline-iosched.c
+++ b/block/deadline-iosched.c
@@ -460,6 +460,11 @@ 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_idle),
+ ELV_ATTR(slice_sync),
+#endif
__ATTR_NULL
};

@@ -477,6 +482,9 @@ 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,
--
1.6.0.6