[PATCH] Make I/O schedulers optional

From: Bernardo Innocenti (bernie_at_develer.com)
Date: 07/27/03

  • Next message: Chris Heath: "Re: i8042 problem" 
    To: torvalds@osdl.org
Date:	Sun, 27 Jul 2003 03:19:04 +0200

    Hello Linus,

    please apply this one. It has been reviewed and approved by
    both Jens Axboe and Andrew Morton.

    --------------------------------------------------------------------------

    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.iosched linux-2.6.0-test1-with_elevator_patch/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-with_elevator_patch/drivers/block/Kconfig.iosched 2003-07-26 14:25:44.000000000 +0200
    @@ -0,0 +1,8 @@
    +config IOSCHED_AS
    + bool "Anticipatory I/O scheduler" if EMBEDDED
    + default y
    +
    +config IOSCHED_DEADLINE
    + bool "Deadline I/O scheduler" if EMBEDDED
    + default y
    +
    diff -Nru linux-2.6.0-test1.orig/drivers/block/Makefile linux-2.6.0-test1-with_elevator_patch/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-with_elevator_patch/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-with_elevator_patch/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-with_elevator_patch/drivers/block/as-iosched.c 2003-07-25 20:19:44.000000000 +0200
    @@ -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-with_elevator_patch/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-with_elevator_patch/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-with_elevator_patch/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-with_elevator_patch/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-with_elevator_patch/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-with_elevator_patch/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/init/Kconfig linux-2.6.0-test1-with_elevator_patch/init/Kconfig
    --- linux-2.6.0-test1.orig/init/Kconfig 2003-07-14 05:37:16.000000000 +0200
    +++ linux-2.6.0-test1-with_elevator_patch/init/Kconfig 2003-07-26 14:25:48.000000000 +0200
    @@ -141,6 +141,8 @@
               Disabling this option will cause the kernel to be built without
               support for epoll family of system calls.
     
    +source "drivers/block/Kconfig.iosched"
    +
     endmenu # General setup
     
     
    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/
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  • Next message: Chris Heath: "Re: i8042 problem"

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