block: add cgroups, kconfig and build bits for BFQ
Add a Kconfig option and do the related Makefile changes to compile
the BFQ I/O scheduler. Also let the cgroups subsystem know about the
BFQ I/O controller.
Signed-off-by: Fabio Checconi <fabio@gandalf.sssup.it>
Signed-off-by: Paolo Valente <paolo.valente@unimore.it>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/block/Kconfig.iosched b/block/Kconfig.iosched
index 7e803fc8..f0681b3 100644
--- a/block/Kconfig.iosched
+++ b/block/Kconfig.iosched
@@ -40,6 +40,27 @@
working environment, suitable for desktop systems.
This is the default I/O scheduler.
+config IOSCHED_BFQ
+ tristate "BFQ I/O scheduler"
+ depends on EXPERIMENTAL
+ default n
+ ---help---
+ The BFQ I/O scheduler tries to distribute bandwidth among
+ all processes in the system, according to their weights,
+ which can be set using task ioprio values. It aims at giving
+ deterministic guarantees on the distribution of the service
+ provided. If compiled built-in (saying Y here), BFQ can
+ be configured to support hierarchical scheduling.
+
+config CGROUP_BFQIO
+ bool "BFQ hierarchical scheduling support"
+ depends on CGROUPS && IOSCHED_BFQ=y
+ default n
+ ---help---
+ Enable hierarchical scheduling in BFQ, using the cgroups
+ filesystem interface. The name of the subsystem will be
+ bfqio.
+
choice
prompt "Default I/O scheduler"
default DEFAULT_CFQ
@@ -56,6 +77,9 @@
config DEFAULT_CFQ
bool "CFQ" if IOSCHED_CFQ=y
+ config DEFAULT_BFQ
+ bool "BFQ" if IOSCHED_BFQ=y
+
config DEFAULT_NOOP
bool "No-op"
@@ -66,6 +90,7 @@
default "anticipatory" if DEFAULT_AS
default "deadline" if DEFAULT_DEADLINE
default "cfq" if DEFAULT_CFQ
+ default "bfq" if DEFAULT_BFQ
default "noop" if DEFAULT_NOOP
endmenu
diff --git a/block/Makefile b/block/Makefile
index bfe7304..90889da 100644
--- a/block/Makefile
+++ b/block/Makefile
@@ -12,6 +12,7 @@
obj-$(CONFIG_IOSCHED_AS) += as-iosched.o
obj-$(CONFIG_IOSCHED_DEADLINE) += deadline-iosched.o
obj-$(CONFIG_IOSCHED_CFQ) += cfq-iosched.o
+obj-$(CONFIG_IOSCHED_BFQ) += bfq-iosched.o
obj-$(CONFIG_BLK_DEV_IO_TRACE) += blktrace.o
obj-$(CONFIG_BLOCK_COMPAT) += compat_ioctl.o
diff --git a/include/linux/cgroup_subsys.h b/include/linux/cgroup_subsys.h
index 9c22396..a091c1c2 100644
--- a/include/linux/cgroup_subsys.h
+++ b/include/linux/cgroup_subsys.h
@@ -54,3 +54,9 @@
#endif
/* */
+
+#ifdef CONFIG_CGROUP_BFQIO
+SUBSYS(bfqio)
+#endif
+
+/* */
