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| author | Nate Diller <nate@namesys.com> | 2005-10-30 15:02:19 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-10-30 17:37:20 -0800 |
| commit | 131dda7f8965a6b794dcde1d84f3ba5951a4d641 (patch) | |
| tree | 604154c55cf0077b128ddb15d7bb99c0bccad4ce /drivers/block | |
| parent | 6dd69f1061bfdeca230509b173438e0731bff767 (diff) | |
| download | lwn-131dda7f8965a6b794dcde1d84f3ba5951a4d641.tar.gz lwn-131dda7f8965a6b794dcde1d84f3ba5951a4d641.zip | |
[PATCH] block cleanups: Add kconfig default iosched submenu
Add a kconfig submenu to select the default I/O scheduler, in case
anticipatory is not compiled in or another default is preferred. Also,
since no-op is always available, we should use it whenever the selected
default is not.
Signed-off-by: Nate Diller <nate@namesys.com>
Acked-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'drivers/block')
| -rw-r--r-- | drivers/block/Kconfig.iosched | 28 | ||||
| -rw-r--r-- | drivers/block/elevator.c | 27 |
2 files changed, 38 insertions, 17 deletions
diff --git a/drivers/block/Kconfig.iosched b/drivers/block/Kconfig.iosched index 6070a480600b..5b90d2fa63b8 100644 --- a/drivers/block/Kconfig.iosched +++ b/drivers/block/Kconfig.iosched @@ -38,4 +38,32 @@ config IOSCHED_CFQ among all processes in the system. It should provide a fair working environment, suitable for desktop systems. +choice + prompt "Default I/O scheduler" + default DEFAULT_AS + help + Select the I/O scheduler which will be used by default for all + block devices. + + config DEFAULT_AS + bool "Anticipatory" if IOSCHED_AS + + config DEFAULT_DEADLINE + bool "Deadline" if IOSCHED_DEADLINE + + config DEFAULT_CFQ + bool "CFQ" if IOSCHED_CFQ + + config DEFAULT_NOOP + bool "No-op" + +endchoice + +config DEFAULT_IOSCHED + string + default "anticipatory" if DEFAULT_AS + default "deadline" if DEFAULT_DEADLINE + default "cfq" if DEFAULT_CFQ + default "noop" if DEFAULT_NOOP + endmenu diff --git a/drivers/block/elevator.c b/drivers/block/elevator.c index 58e881bfd189..3b652eba2d20 100644 --- a/drivers/block/elevator.c +++ b/drivers/block/elevator.c @@ -147,24 +147,17 @@ static void elevator_setup_default(void) struct elevator_type *e; /* - * check if default is set and exists + * If default has not been set, use the compiled-in selection. */ - if (chosen_elevator[0] && (e = elevator_get(chosen_elevator))) { - elevator_put(e); - return; - } - -#if defined(CONFIG_IOSCHED_AS) - strcpy(chosen_elevator, "anticipatory"); -#elif defined(CONFIG_IOSCHED_DEADLINE) - strcpy(chosen_elevator, "deadline"); -#elif defined(CONFIG_IOSCHED_CFQ) - strcpy(chosen_elevator, "cfq"); -#elif defined(CONFIG_IOSCHED_NOOP) - strcpy(chosen_elevator, "noop"); -#else -#error "You must build at least 1 IO scheduler into the kernel" -#endif + if (!chosen_elevator[0]) + strcpy(chosen_elevator, CONFIG_DEFAULT_IOSCHED); + + /* + * If the given scheduler is not available, fall back to no-op. + */ + if (!(e = elevator_find(chosen_elevator))) + strcpy(chosen_elevator, "noop"); + elevator_put(e); } static int __init elevator_setup(char *str) |