Revision d7831a0bdf06b9f722b947bb0c205ff7d77cebd8 authored by Richard Kennedy on 30 June 2009, 18:41:35 UTC, committed by Linus Torvalds on 01 July 2009, 01:56:01 UTC
balance_dirty_pages can overreact and move all of the dirty pages to writeback unnecessarily. balance_dirty_pages makes its decision to throttle based on the number of dirty plus writeback pages that are over the calculated limit,so it will continue to move pages even when there are plenty of pages in writeback and less than the threshold still dirty. This allows it to overshoot its limits and move all the dirty pages to writeback while waiting for the drives to catch up and empty the writeback list. A simple fio test easily demonstrates this problem. fio --name=f1 --directory=/disk1 --size=2G -rw=write --name=f2 --directory=/disk2 --size=1G --rw=write --startdelay=10 This is the simplest fix I could find, but I'm not entirely sure that it alone will be enough for all cases. But it certainly is an improvement on my desktop machine writing to 2 disks. Do we need something more for machines with large arrays where bdi_threshold * number_of_drives is greater than the dirty_ratio ? Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent df279ca
Kconfig
#
# Input device configuration
#
menu "Input device support"
depends on !S390
config INPUT
tristate "Generic input layer (needed for keyboard, mouse, ...)" if EMBEDDED
default y
---help---
Say Y here if you have any input device (mouse, keyboard, tablet,
joystick, steering wheel ...) connected to your system and want
it to be available to applications. This includes standard PS/2
keyboard and mouse.
Say N here if you have a headless (no monitor, no keyboard) system.
More information is available: <file:Documentation/input/input.txt>
If unsure, say Y.
To compile this driver as a module, choose M here: the
module will be called input.
if INPUT
config INPUT_FF_MEMLESS
tristate "Support for memoryless force-feedback devices"
default n
---help---
Say Y here if you have memoryless force-feedback input device
such as Logitech WingMan Force 3D, ThrustMaster FireStorm Dual
Power 2, or similar. You will also need to enable hardware-specific
driver.
If unsure, say N.
To compile this driver as a module, choose M here: the
module will be called ff-memless.
config INPUT_POLLDEV
tristate "Polled input device skeleton"
help
Say Y here if you are using a driver for an input
device that periodically polls hardware state. This
option is only useful for out-of-tree drivers since
in-tree drivers select it automatically.
If unsure, say N.
To compile this driver as a module, choose M here: the
module will be called input-polldev.
comment "Userland interfaces"
config INPUT_MOUSEDEV
tristate "Mouse interface" if EMBEDDED
default y
---help---
Say Y here if you want your mouse to be accessible as char devices
13:32+ - /dev/input/mouseX and 13:63 - /dev/input/mice as an
emulated IntelliMouse Explorer PS/2 mouse. That way, all user space
programs (including SVGAlib, GPM and X) will be able to use your
mouse.
If unsure, say Y.
To compile this driver as a module, choose M here: the
module will be called mousedev.
config INPUT_MOUSEDEV_PSAUX
bool "Provide legacy /dev/psaux device"
default y
depends on INPUT_MOUSEDEV
---help---
Say Y here if you want your mouse also be accessible as char device
10:1 - /dev/psaux. The data available through /dev/psaux is exactly
the same as the data from /dev/input/mice.
If unsure, say Y.
config INPUT_MOUSEDEV_SCREEN_X
int "Horizontal screen resolution"
depends on INPUT_MOUSEDEV
default "1024"
help
If you're using a digitizer, or a graphic tablet, and want to use
it as a mouse then the mousedev driver needs to know the X window
screen resolution you are using to correctly scale the data. If
you're not using a digitizer, this value is ignored.
config INPUT_MOUSEDEV_SCREEN_Y
int "Vertical screen resolution"
depends on INPUT_MOUSEDEV
default "768"
help
If you're using a digitizer, or a graphic tablet, and want to use
it as a mouse then the mousedev driver needs to know the X window
screen resolution you are using to correctly scale the data. If
you're not using a digitizer, this value is ignored.
config INPUT_JOYDEV
tristate "Joystick interface"
---help---
Say Y here if you want your joystick or gamepad to be
accessible as char device 13:0+ - /dev/input/jsX device.
If unsure, say Y.
More information is available: <file:Documentation/input/joystick.txt>
To compile this driver as a module, choose M here: the
module will be called joydev.
config INPUT_EVDEV
tristate "Event interface"
help
Say Y here if you want your input device events be accessible
under char device 13:64+ - /dev/input/eventX in a generic way.
To compile this driver as a module, choose M here: the
module will be called evdev.
config INPUT_EVBUG
tristate "Event debugging"
---help---
Say Y here if you have a problem with the input subsystem and
want all events (keypresses, mouse movements), to be output to
the system log. While this is useful for debugging, it's also
a security threat - your keypresses include your passwords, of
course.
If unsure, say N.
To compile this driver as a module, choose M here: the
module will be called evbug.
config INPUT_APMPOWER
tristate "Input Power Event -> APM Bridge" if EMBEDDED
depends on INPUT && APM_EMULATION
---help---
Say Y here if you want suspend key events to trigger a user
requested suspend through APM. This is useful on embedded
systems where such behaviour is desired without userspace
interaction. If unsure, say N.
To compile this driver as a module, choose M here: the
module will be called apm-power.
config XEN_KBDDEV_FRONTEND
tristate "Xen virtual keyboard and mouse support"
depends on XEN_FBDEV_FRONTEND
default y
help
This driver implements the front-end of the Xen virtual
keyboard and mouse device driver. It communicates with a back-end
in another domain.
comment "Input Device Drivers"
source "drivers/input/keyboard/Kconfig"
source "drivers/input/mouse/Kconfig"
source "drivers/input/joystick/Kconfig"
source "drivers/input/tablet/Kconfig"
source "drivers/input/touchscreen/Kconfig"
source "drivers/input/misc/Kconfig"
endif
menu "Hardware I/O ports"
source "drivers/input/serio/Kconfig"
source "drivers/input/gameport/Kconfig"
endmenu
endmenu
![swh spinner](/static/img/swh-spinner.gif)
Computing file changes ...