On Friday 25 July 2003 17:46, Christoph Hellwig wrote:
> On Thu, Jul 24, 2003 at 10:27:16PM +0200, Bernardo Innocenti wrote:
> > Some of the bigger 2.6 additions cannot be configured out.
> > I wish sysfs and the different I/O schedulers could be removed.
>
> Removing the I/O schedulers is pretty trivial, please come up with a
> patch to make both of them optional and maybe add a trivial noop one.
Here it is, attached below. I've tested it on both i386 and m68knommu.
Jens, could you please review this patch and push to Linus if you
like it?
> Removing sysfs should also be pretty trivial but I'm not sure whether
> you really want that.
I really don't need sysfs on uClinux. I have no programs using it.
Removing sysfs appears to be a little bit more difficult, though.
I'll try tomorrow.
--------------------------------------------------------------------------
Add kconfig options to allow excluding either or both the I/O schedulers.
Mostly useful for embedded systems (save ~13KB):
With my desktop PC (i386) kernel:
text data bss dec hex filename
2210707 475856 150444 2837007 2b4a0f vmlinux_with_ioscheds
2197763 473446 150380 2821589 2b0dd5 vmlinux_without_ioscheds
With my uClinux (m68knommu) kernel:
text data bss dec hex filename
807760 47384 78884 934028 e408c linux_without_ioscheds
819276 52460 78896 950632 e8168 linux_with_ioscheds
diff -Nru linux-2.6.0-test1.orig/drivers/block/Kconfig linux-2.6.0-test1/drivers/block/Kconfig
--- linux-2.6.0-test1.orig/drivers/block/Kconfig 2003-07-14 05:31:51.000000000 +0200
+++ linux-2.6.0-test1/drivers/block/Kconfig 2003-07-25 18:59:19.000000000 +0200
@@ -4,6 +4,10 @@
menu "Block devices"
+menu "I/O schedulers"
+source "drivers/block/Kconfig.iosched"
+endmenu
+
config BLK_DEV_FD
tristate "Normal floppy disk support"
depends on !X86_PC9800
diff -Nru linux-2.6.0-test1.orig/drivers/block/Kconfig.iosched linux-2.6.0-test1/drivers/block/Kconfig.iosched
--- linux-2.6.0-test1.orig/drivers/block/Kconfig.iosched 1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.0-test1/drivers/block/Kconfig.iosched 2003-07-25 18:59:53.000000000 +0200
@@ -0,0 +1,8 @@
+config IOSCHED_AS
+ bool "Anticipatory I/O scheduler"
+ default y
+
+config IOSCHED_DEADLINE
+ bool "Deadline I/O scheduler"
+ default y
+
diff -Nru linux-2.6.0-test1.orig/drivers/block/Makefile linux-2.6.0-test1/drivers/block/Makefile
--- linux-2.6.0-test1.orig/drivers/block/Makefile 2003-07-14 05:37:16.000000000 +0200
+++ linux-2.6.0-test1/drivers/block/Makefile 2003-07-25 20:21:50.000000000 +0200
@@ -13,9 +13,10 @@
# kblockd threads
#
-obj-y := elevator.o ll_rw_blk.o ioctl.o genhd.o scsi_ioctl.o \
- deadline-iosched.o as-iosched.o
+obj-y := elevator.o ll_rw_blk.o ioctl.o genhd.o scsi_ioctl.o
+obj-$(CONFIG_IOSCHED_AS) += as-iosched.o
+obj-$(CONFIG_IOSCHED_DEADLINE) += deadline-iosched.o
obj-$(CONFIG_MAC_FLOPPY) += swim3.o
obj-$(CONFIG_BLK_DEV_FD) += floppy.o
obj-$(CONFIG_BLK_DEV_FD98) += floppy98.o
diff -Nru linux-2.6.0-test1.orig/drivers/block/as-iosched.c linux-2.6.0-test1/drivers/block/as-iosched.c
--- linux-2.6.0-test1.orig/drivers/block/as-iosched.c 2003-07-14 05:28:54.000000000 +0200
+++ linux-2.6.0-test1/drivers/block/as-iosched.c 2003-07-25 20:19:44.000000000 +0200
@@ -1,7 +1,7 @@
/*
* linux/drivers/block/as-iosched.c
*
- * Anticipatory & deadline i/o scheduler.
+ * Anticipatory i/o scheduler.
*
* Copyright (C) 2002 Jens Axboe <axboe@suse.de>
* Nick Piggin <piggin@cyberone.com.au>
@@ -1832,6 +1832,7 @@
.elevator_exit_fn = as_exit,
.elevator_ktype = &as_ktype,
+ .elevator_name = "anticipatory scheduling",
};
EXPORT_SYMBOL(iosched_as);
diff -Nru linux-2.6.0-test1.orig/drivers/block/deadline-iosched.c linux-2.6.0-test1/drivers/block/deadline-iosched.c
--- linux-2.6.0-test1.orig/drivers/block/deadline-iosched.c 2003-07-14 05:37:15.000000000 +0200
+++ linux-2.6.0-test1/drivers/block/deadline-iosched.c 2003-07-25 20:20:53.000000000 +0200
@@ -941,6 +941,7 @@
.elevator_exit_fn = deadline_exit,
.elevator_ktype = &deadline_ktype,
+ .elevator_name = "deadline",
};
EXPORT_SYMBOL(iosched_deadline);
diff -Nru linux-2.6.0-test1.orig/drivers/block/elevator.c linux-2.6.0-test1/drivers/block/elevator.c
--- linux-2.6.0-test1.orig/drivers/block/elevator.c 2003-07-14 05:36:48.000000000 +0200
+++ linux-2.6.0-test1/drivers/block/elevator.c 2003-07-25 19:27:41.000000000 +0200
@@ -409,6 +409,7 @@
.elevator_merge_req_fn = elevator_noop_merge_requests,
.elevator_next_req_fn = elevator_noop_next_request,
.elevator_add_req_fn = elevator_noop_add_request,
+ .elevator_name = "noop",
};
module_init(elevator_global_init);
diff -Nru linux-2.6.0-test1.orig/drivers/block/ll_rw_blk.c linux-2.6.0-test1/drivers/block/ll_rw_blk.c
--- linux-2.6.0-test1.orig/drivers/block/ll_rw_blk.c 2003-07-14 05:30:40.000000000 +0200
+++ linux-2.6.0-test1/drivers/block/ll_rw_blk.c 2003-07-25 19:27:02.000000000 +0200
@@ -1205,17 +1205,31 @@
static int __make_request(request_queue_t *, struct bio *);
-static elevator_t *chosen_elevator = &iosched_as;
+static elevator_t *chosen_elevator =
+#if defined(CONFIG_IOSCHED_AS)
+ &iosched_as;
+#elif defined(CONFIG_IOSCHED_DEADLINE)
+ &iosched_deadline;
+#else
+ &elevator_noop;
+#endif
+#if defined(CONFIG_IOSCHED_AS) || defined(CONFIG_IOSCHED_DEADLINE)
static int __init elevator_setup(char *str)
{
+#ifdef CONFIG_IOSCHED_DEADLINE
if (!strcmp(str, "deadline"))
chosen_elevator = &iosched_deadline;
+#endif
+#ifdef CONFIG_IOSCHED_AS
if (!strcmp(str, "as"))
chosen_elevator = &iosched_as;
+#endif
return 1;
}
+
__setup("elevator=", elevator_setup);
+#endif /* CONFIG_IOSCHED_AS || CONFIG_IOSCHED_DEADLINE */
/**
* blk_init_queue - prepare a request queue for use with a block device
@@ -1255,10 +1269,7 @@
if (!printed) {
printed = 1;
- if (chosen_elevator == &iosched_deadline)
- printk("deadline elevator\n");
- else if (chosen_elevator == &iosched_as)
- printk("anticipatory scheduling elevator\n");
+ printk("Using %s elevator\n", chosen_elevator->elevator_name);
}
if ((ret = elevator_init(q, chosen_elevator))) {
diff -Nru linux-2.6.0-test1.orig/include/linux/elevator.h linux-2.6.0-test1/include/linux/elevator.h
--- linux-2.6.0-test1.orig/include/linux/elevator.h 2003-07-14 05:29:27.000000000 +0200
+++ linux-2.6.0-test1/include/linux/elevator.h 2003-07-25 19:18:39.000000000 +0200
@@ -52,6 +52,7 @@
struct kobject kobj;
struct kobj_type *elevator_ktype;
+ const char *elevator_name;
};
/*
-- // Bernardo Innocenti - Develer S.r.l., R&D dept. \X/ http://www.develer.com/Please don't send Word attachments - http://www.gnu.org/philosophy/no-word-attachments.html
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