Commit 131dda7f authored by Nate Diller's avatar Nate Diller Committed by Linus Torvalds

[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: default avatarNate Diller <nate@namesys.com>
Acked-by: default avatarJens Axboe <axboe@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 6dd69f10
......@@ -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
......@@ -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)
......
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