sio and vr io-scheduler added

block/Kconfig.iosched

@@ -43,6 +43,23 @@ config CFQ_GROUP_IOSCHED
 	---help---
 	  Enable group IO scheduling in CFQ.
 
+config IOSCHED_VR
+	tristate "V(R) I/O scheduler"
+	default n
+	---help---
+		Requests are chosen according to SSTF with a penalty of rev_penalty
+		for switching head direction.
+
+config IOSCHED_SIO
+  tristate "Simple I/O scheduler"
+  default y
+  ---help---
+    The Simple I/O scheduler is an extremely simple scheduler,
+    based on noop and deadline, that relies on deadlines to
+    ensure fairness. The algorithm does not do any sorting but
+    basic merging, trying to keep a minimum overhead. It is aimed
+    mainly for aleatory access devices (eg: flash devices).
+
 choice
 	prompt "Default I/O scheduler"
 	default DEFAULT_CFQ
@@ -58,6 +75,12 @@ choice
 
 	config DEFAULT_NOOP
 		bool "No-op"
+
+	config DEFAULT_VR
+		bool "V(R)" if IOSCHED_VR=y
+
+	config DEFAULT_SIO
+		bool "SIO" if IOSCHED_SIO=y
 
 endchoice
 
@@ -66,6 +89,8 @@ config DEFAULT_IOSCHED
 	default "deadline" if DEFAULT_DEADLINE
 	default "cfq" if DEFAULT_CFQ
 	default "noop" if DEFAULT_NOOP
+	default "vr" if DEFAULT_VR
+	default "sio" if DEFAULT_SIO
 
 endmenu
 

block/Makefile

@@ -13,6 +13,9 @@ 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-$(CONFIG_IOSCHED_VR) += vr-iosched.o
+obj-$(CONFIG_IOSCHED_SIO) += sio-iosched.o
+
 
 obj-$(CONFIG_BLOCK_COMPAT)	+= compat_ioctl.o
 obj-$(CONFIG_BLK_DEV_INTEGRITY)	+= blk-integrity.o

block/deadline-iosched.c

@@ -19,7 +19,7 @@
  */
 static const int read_expire = HZ / 2;  /* max time before a read is submitted. */
 static const int write_expire = 5 * HZ; /* ditto for writes, these limits are SOFT! */
-static const int writes_starved = 2;    /* max times reads can starve a write */
+static const int writes_starved = 1;    /* max times reads can starve a write */
 static const int fifo_batch = 16;       /* # of sequential requests treated as one
 				     by the above parameters. For throughput. */