linux/arch/h8300/Kconfig

223 lines
5.5 KiB
Plaintext
Raw Normal View History

config H8300
bool
default y
select HAVE_IDE
select HAVE_GENERIC_HARDIRQS
select ARCH_WANT_IPC_PARSE_VERSION
select GENERIC_IRQ_SHOW
select GENERIC_CPU_DEVICES
config SYMBOL_PREFIX
string
default "_"
config MMU
bool
default n
config SWAP
bool
default n
config ZONE_DMA
bool
default y
config FPU
bool
default n
config RWSEM_GENERIC_SPINLOCK
bool
default y
config RWSEM_XCHGADD_ALGORITHM
bool
default n
config ARCH_HAS_ILOG2_U32
bool
default n
config ARCH_HAS_ILOG2_U64
bool
default n
config GENERIC_HWEIGHT
bool
default y
config GENERIC_CALIBRATE_DELAY
bool
default y
config GENERIC_BUG
bool
depends on BUG
config TIME_LOW_RES
bool
default y
config NO_IOPORT
def_bool y
config NO_DMA
def_bool y
config ISA
bool
default y
config PCI
bool
default n
avoid overflows in kernel/time.c When the conversion factor between jiffies and milli- or microseconds is not a single multiply or divide, as for the case of HZ == 300, we currently do a multiply followed by a divide. The intervening result, however, is subject to overflows, especially since the fraction is not simplified (for HZ == 300, we multiply by 300 and divide by 1000). This is exposed to the user when passing a large timeout to poll(), for example. This patch replaces the multiply-divide with a reciprocal multiplication on 32-bit platforms. When the input is an unsigned long, there is no portable way to do this on 64-bit platforms there is no portable way to do this since it requires a 128-bit intermediate result (which gcc does support on 64-bit platforms but may generate libgcc calls, e.g. on 64-bit s390), but since the output is a 32-bit integer in the cases affected, just simplify the multiply-divide (*3/10 instead of *300/1000). The reciprocal multiply used can have off-by-one errors in the upper half of the valid output range. This could be avoided at the expense of having to deal with a potential 65-bit intermediate result. Since the intent is to avoid overflow problems and most of the other time conversions are only semiexact, the off-by-one errors were considered an acceptable tradeoff. At Ralf Baechle's suggestion, this version uses a Perl script to compute the necessary constants. We already have dependencies on Perl for kernel compiles. This does, however, require the Perl module Math::BigInt, which is included in the standard Perl distribution starting with version 5.8.0. In order to support older versions of Perl, include a table of canned constants in the script itself, and structure the script so that Math::BigInt isn't required if pulling values from said table. Running the script requires that the HZ value is available from the Makefile. Thus, this patch also adds the Kconfig variable CONFIG_HZ to the architectures which didn't already have it (alpha, cris, frv, h8300, m32r, m68k, m68knommu, sparc, v850, and xtensa.) It does *not* touch the sh or sh64 architectures, since Paul Mundt has dealt with those separately in the sh tree. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Ralf Baechle <ralf@linux-mips.org>, Cc: Sam Ravnborg <sam@ravnborg.org>, Cc: Paul Mundt <lethal@linux-sh.org>, Cc: Richard Henderson <rth@twiddle.net>, Cc: Michael Starvik <starvik@axis.com>, Cc: David Howells <dhowells@redhat.com>, Cc: Yoshinori Sato <ysato@users.sourceforge.jp>, Cc: Hirokazu Takata <takata@linux-m32r.org>, Cc: Geert Uytterhoeven <geert@linux-m68k.org>, Cc: Roman Zippel <zippel@linux-m68k.org>, Cc: William L. Irwin <sparclinux@vger.kernel.org>, Cc: Chris Zankel <chris@zankel.net>, Cc: H. Peter Anvin <hpa@zytor.com>, Cc: Jan Engelhardt <jengelh@computergmbh.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 12:21:26 +00:00
config HZ
int
default 100
source "init/Kconfig"
container freezer: implement freezer cgroup subsystem This patch implements a new freezer subsystem in the control groups framework. It provides a way to stop and resume execution of all tasks in a cgroup by writing in the cgroup filesystem. The freezer subsystem in the container filesystem defines a file named freezer.state. Writing "FROZEN" to the state file will freeze all tasks in the cgroup. Subsequently writing "RUNNING" will unfreeze the tasks in the cgroup. Reading will return the current state. * Examples of usage : # mkdir /containers/freezer # mount -t cgroup -ofreezer freezer /containers # mkdir /containers/0 # echo $some_pid > /containers/0/tasks to get status of the freezer subsystem : # cat /containers/0/freezer.state RUNNING to freeze all tasks in the container : # echo FROZEN > /containers/0/freezer.state # cat /containers/0/freezer.state FREEZING # cat /containers/0/freezer.state FROZEN to unfreeze all tasks in the container : # echo RUNNING > /containers/0/freezer.state # cat /containers/0/freezer.state RUNNING This is the basic mechanism which should do the right thing for user space task in a simple scenario. It's important to note that freezing can be incomplete. In that case we return EBUSY. This means that some tasks in the cgroup are busy doing something that prevents us from completely freezing the cgroup at this time. After EBUSY, the cgroup will remain partially frozen -- reflected by freezer.state reporting "FREEZING" when read. The state will remain "FREEZING" until one of these things happens: 1) Userspace cancels the freezing operation by writing "RUNNING" to the freezer.state file 2) Userspace retries the freezing operation by writing "FROZEN" to the freezer.state file (writing "FREEZING" is not legal and returns EIO) 3) The tasks that blocked the cgroup from entering the "FROZEN" state disappear from the cgroup's set of tasks. [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: export thaw_process] Signed-off-by: Cedric Le Goater <clg@fr.ibm.com> Signed-off-by: Matt Helsley <matthltc@us.ibm.com> Acked-by: Serge E. Hallyn <serue@us.ibm.com> Tested-by: Matt Helsley <matthltc@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-19 03:27:21 +00:00
source "kernel/Kconfig.freezer"
source "arch/h8300/Kconfig.cpu"
menu "Executable file formats"
source "fs/Kconfig.binfmt"
endmenu
source "net/Kconfig"
source "drivers/base/Kconfig"
source "drivers/mtd/Kconfig"
source "drivers/block/Kconfig"
source "drivers/ide/Kconfig"
source "arch/h8300/Kconfig.ide"
source "drivers/net/Kconfig"
#
# input - input/joystick depends on it. As does USB.
#
source "drivers/input/Kconfig"
menu "Character devices"
config VT
bool "Virtual terminal"
---help---
If you say Y here, you will get support for terminal devices with
display and keyboard devices. These are called "virtual" because you
can run several virtual terminals (also called virtual consoles) on
one physical terminal. This is rather useful, for example one
virtual terminal can collect system messages and warnings, another
one can be used for a text-mode user session, and a third could run
an X session, all in parallel. Switching between virtual terminals
is done with certain key combinations, usually Alt-<function key>.
The setterm command ("man setterm") can be used to change the
properties (such as colors or beeping) of a virtual terminal. The
man page console_codes(4) ("man console_codes") contains the special
character sequences that can be used to change those properties
directly. The fonts used on virtual terminals can be changed with
the setfont ("man setfont") command and the key bindings are defined
with the loadkeys ("man loadkeys") command.
You need at least one virtual terminal device in order to make use
of your keyboard and monitor. Therefore, only people configuring an
embedded system would want to say N here in order to save some
memory; the only way to log into such a system is then via a serial
or network connection.
If unsure, say Y, or else you won't be able to do much with your new
shiny Linux system :-)
config VT_CONSOLE
bool "Support for console on virtual terminal"
depends on VT
---help---
The system console is the device which receives all kernel messages
and warnings and which allows logins in single user mode. If you
answer Y here, a virtual terminal (the device used to interact with
a physical terminal) can be used as system console. This is the most
common mode of operations, so you should say Y here unless you want
the kernel messages be output only to a serial port (in which case
you should say Y to "Console on serial port", below).
If you do say Y here, by default the currently visible virtual
terminal (/dev/tty0) will be used as system console. You can change
that with a kernel command line option such as "console=tty3" which
would use the third virtual terminal as system console. (Try "man
bootparam" or see the documentation of your boot loader (lilo or
loadlin) about how to pass options to the kernel at boot time.)
If unsure, say Y.
config HW_CONSOLE
bool
depends on VT
default y
comment "Unix98 PTY support"
config UNIX98_PTYS
bool "Unix98 PTY support"
---help---
A pseudo terminal (PTY) is a software device consisting of two
halves: a master and a slave. The slave device behaves identical to
a physical terminal; the master device is used by a process to
read data from and write data to the slave, thereby emulating a
terminal. Typical programs for the master side are telnet servers
and xterms.
Linux has traditionally used the BSD-like names /dev/ptyxx for
masters and /dev/ttyxx for slaves of pseudo terminals. This scheme
has a number of problems. The GNU C library glibc 2.1 and later,
however, supports the Unix98 naming standard: in order to acquire a
pseudo terminal, a process opens /dev/ptmx; the number of the pseudo
terminal is then made available to the process and the pseudo
terminal slave can be accessed as /dev/pts/<number>. What was
traditionally /dev/ttyp2 will then be /dev/pts/2, for example.
The entries in /dev/pts/ are created on the fly by a virtual
file system; therefore, if you say Y here you should say Y to
"/dev/pts file system for Unix98 PTYs" as well.
If you want to say Y here, you need to have the C library glibc 2.1
or later (equal to libc-6.1, check with "ls -l /lib/libc.so.*").
Read the instructions in <file:Documentation/Changes> pertaining to
pseudo terminals. It's safe to say N.
source "drivers/char/pcmcia/Kconfig"
source "drivers/tty/serial/Kconfig"
source "drivers/i2c/Kconfig"
source "drivers/hwmon/Kconfig"
source "drivers/usb/Kconfig"
source "drivers/uwb/Kconfig"
endmenu
source "drivers/staging/Kconfig"
source "fs/Kconfig"
source "arch/h8300/Kconfig.debug"
source "security/Kconfig"
source "crypto/Kconfig"
source "lib/Kconfig"