[PATCH 11/20] io-controller: noop changes for hierarchical fair queuing

Vivek Goyal
2009-05-26T22:46:09Z

This patch changes noop to use queue scheduling code from elevator layer.
One can go back to old noop by deselecting CONFIG_IOSCHED_NOOP_HIER.

Signed-off-by: Nauman Rafique <nauman@google.com>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
---
block/Kconfig.iosched | 11 +++++++++++
block/noop-iosched.c | 3 +++
2 files changed, 14 insertions(+), 0 deletions(-)

diff --git a/block/Kconfig.iosched b/block/Kconfig.iosched
index a91a807..9da6657 100644
--- a/block/Kconfig.iosched
+++ b/block/Kconfig.iosched
@@ -25,6 +25,17 @@ config IOSCHED_NOOP
that do their own scheduling and require only minimal assistance from
the kernel.

+config IOSCHED_NOOP_HIER
+ bool "Noop Hierarchical Scheduling support"
+ depends on IOSCHED_NOOP && CGROUPS
+ select ELV_FAIR_QUEUING
+ select GROUP_IOSCHED
+ default n
+ ---help---
+ Enable hierarhical scheduling in noop. In this mode noop keeps
+ one IO queue per cgroup instead of a global queue. Elevator
+ fair queuing logic ensures fairness among various queues.
+
config IOSCHED_AS
tristate "Anticipatory I/O scheduler"
default y
diff --git a/block/noop-iosched.c b/block/noop-iosched.c
index d587832..73e571d 100644
--- a/block/noop-iosched.c
+++ b/block/noop-iosched.c
@@ -92,6 +92,9 @@ static struct elevator_type elevator_noop = {
.elevator_alloc_sched_queue_fn = noop_alloc_noop_queue,
.elevator_free_sched_queue_fn = noop_free_noop_queue,
},
+#ifdef CONFIG_IOSCHED_NOOP_HIER
+ .elevator_features = ELV_IOSCHED_NEED_FQ | ELV_IOSCHED_SINGLE_IOQ,
+#endif
.elevator_name = "noop",
.elevator_owner = THIS_MODULE,
};
--
1.6.0.1