Apollo BFQ IO Sched

Documentation/block/00-INDEX

@@ -1,5 +1,7 @@
 00-INDEX
 	- This file
+bfq-iosched.txt
+	- BFQ IO scheduler and its tunables
 biodoc.txt
 	- Notes on the Generic Block Layer Rewrite in Linux 2.5
 biovecs.txt

arch/arm64/configs/exynos9810_defconfig

@@ -348,9 +348,12 @@ CONFIG_BLK_MQ_PCI=y
 CONFIG_IOSCHED_NOOP=y
 # CONFIG_IOSCHED_DEADLINE is not set
 CONFIG_IOSCHED_CFQ=y
-CONFIG_DEFAULT_CFQ=y
+# CONFIG_DEFAULT_CFQ is not set
+CONFIG_BFQ_GROUP_IOSCHED=y
+CONFIG_IOSCHED_BFQ=y
+CONFIG_BFQ_DEFAULT=y
 # CONFIG_DEFAULT_NOOP is not set
-CONFIG_DEFAULT_IOSCHED="cfq"
+CONFIG_DEFAULT_IOSCHED="bfq"
 CONFIG_ASN1=y
 CONFIG_UNINLINE_SPIN_UNLOCK=y
 CONFIG_ARCH_SUPPORTS_ATOMIC_RMW=y

block/Kconfig.iosched

@@ -38,6 +38,25 @@ config CFQ_GROUP_IOSCHED
 	default n
 	---help---
 	  Enable group IO scheduling in CFQ.
+
+config IOSCHED_BFQ
+	tristate "BFQ I/O scheduler"
+	default n
+	---help---
+	The BFQ I/O scheduler distributes bandwidth among all
+	processes according to their weights, regardless of the
+	device parameters and with any workload. It also guarantees
+	a low latency to interactive and soft real-time applications.
+	Details in Documentation/block/bfq-iosched.txt
+
+config BFQ_GROUP_IOSCHED
+	bool "BFQ hierarchical scheduling support"
+	depends on IOSCHED_BFQ && BLK_CGROUP
+	default n
+	---help---
+
+	Enable hierarchical scheduling in BFQ, using the blkio
+	(cgroups-v1) or io (cgroups-v2) controller.
 
 choice
 	prompt "Default I/O scheduler"
@@ -51,6 +70,16 @@ choice
 
 	config DEFAULT_CFQ
 		bool "CFQ" if IOSCHED_CFQ=y
+
+	config DEFAULT_BFQ
+		bool "BFQ" if IOSCHED_BFQ=y
+		help
+		  Selects BFQ as the default I/O scheduler which will be
+		  used by default for all block devices.
+		  The BFQ I/O scheduler aims at distributing the bandwidth
+		  as desired, independently of the disk parameters and with
+		  any workload. It also tries to guarantee low latency to
+		  interactive and soft real-time applications.
 
 	config DEFAULT_NOOP
 		bool "No-op"
@@ -61,6 +90,7 @@ config DEFAULT_IOSCHED
 	string
 	default "deadline" if DEFAULT_DEADLINE
 	default "cfq" if DEFAULT_CFQ
+	default "bfq" if DEFAULT_BFQ	
 	default "noop" if DEFAULT_NOOP
 
 endmenu

block/Makefile

@@ -23,6 +23,7 @@ obj-$(CONFIG_BLK_DEV_THROTTLING)	+= blk-throttle.o
 obj-$(CONFIG_IOSCHED_NOOP)	+= noop-iosched.o
 obj-$(CONFIG_IOSCHED_DEADLINE)	+= deadline-iosched.o
 obj-$(CONFIG_IOSCHED_CFQ)	+= cfq-iosched.o
+obj-$(CONFIG_IOSCHED_BFQ)	+= bfq-iosched.o
 
 obj-$(CONFIG_BLOCK_COMPAT)	+= compat_ioctl.o
 obj-$(CONFIG_BLK_CMDLINE_PARSER)	+= cmdline-parser.o