The header file <linux/compiler.h> already enforces a suitably recent
version of gcc, so there's no point checking for that again.
Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Generic Process Control Groups
--------------------------
There have recently been various proposals floating around for
resource management/accounting and other task grouping subsystems in
the kernel, including ResGroups, User BeanCounters, NSProxy
cgroups, and others. These all need the basic abstraction of being
able to group together multiple processes in an aggregate, in order to
track/limit the resources permitted to those processes, or control
other behaviour of the processes, and all implement this grouping in
different ways.
This patchset provides a framework for tracking and grouping processes
into arbitrary "cgroups" and assigning arbitrary state to those
groupings, in order to control the behaviour of the cgroup as an
aggregate.
The intention is that the various resource management and
virtualization/cgroup efforts can also become task cgroup
clients, with the result that:
- the userspace APIs are (somewhat) normalised
- it's easier to test e.g. the ResGroups CPU controller in
conjunction with the BeanCounters memory controller, or use either of
them as the resource-control portion of a virtual server system.
- the additional kernel footprint of any of the competing resource
management systems is substantially reduced, since it doesn't need
to provide process grouping/containment, hence improving their
chances of getting into the kernel
This patch:
Add the main task cgroups framework - the cgroup filesystem, and the
basic structures for tracking membership and associating subsystem state
objects to tasks.
Signed-off-by: Paul Menage <menage@google.com>
Cc: Serge E. Hallyn <serue@us.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Paul Jackson <pj@sgi.com>
Cc: Kirill Korotaev <dev@openvz.org>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Alexey Dobriyan reports that maxcpus=1 is still broken in 2.6.23-rc4:
if CONFIG_HOTPLUG_CPU is not set, x86_64 bootup oopses in show_stat() -
for_each_possible_cpu accesses a per-cpu area which was never set up.
Alexey identified commit 61ec7567db
(ACPI: boot correctly with "nosmp" or "maxcpus=0") as the origin;
but it's not really to blame, just exposes a bug in 2.6.23-rc1's commit
8b3b295502 (Especially when !CONFIG_HOTPLUG_CPU,
avoid needlessy allocating resources for CPUs that can never become available).
rc1's test for max_cpus < 2 in start_kernel() wasn't working because
max_cpus was still NR_CPUS at that point: until rc4 moved the maxcpus
parsing earlier. Now it sets cpu_possible_map to 1 before allocating
all possible per-cpu areas; then smp_init() expands cpu_possible_map
to cpu_present_map (0xf in my case) later on.
rc1's commit has good intentions, but expects cpu_present_map to be
limited by maxcpus, which is only the case on i386. cpus_and(possible,
possible,present) might be good, but needs an audit of cpu_present_map
uses - there may well be assumptions that any cpu present is possible.
So stay safe for now and just revert those #ifndef CONFIG_HOTPLUG_CPU
optimizations in rc1's commit.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: Alexey Dobriyan <adobriyan@sw.ru>
Cc: Len Brown <lenb@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 61ec7567db ('ACPI: boot correctly
with "nosmp" or "maxcpus=0"') broke 'maxcpus=' handling on x86[-64].
maxcpus=N is now having no effect on x86_64, and freezing bootup on i386
(because of inconsistency with the separate maxcpus parsing down in
arch/i386, I guess). That's because early_param parsing is a little
different from __setup parsing, and needs the "=" omitted: then it seems
to work as the original commit intended (no mention of IO-APIC in
/proc/interrupts when maxcpus=0).
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Len Brown <len.brown@intel.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In MPS mode, "nosmp" and "maxcpus=0" boot a UP kernel with IOAPIC disabled.
However, in ACPI mode, these parameters didn't completely disable
the IO APIC initialization code and boot failed.
init/main.c:
Disable the IO_APIC if "nosmp" or "maxcpus=0"
undefine disable_ioapic_setup() when it doesn't apply.
i386:
delete ioapic_setup(), it was a duplicate of parse_noapic()
delete undefinition of disable_ioapic_setup()
x86_64:
rename disable_ioapic_setup() to parse_noapic() to match i386
define disable_ioapic_setup() in header to match i386
http://bugzilla.kernel.org/show_bug.cgi?id=1641
Acked-by: Andi Kleen <ak@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>
Beacuse SERIAL_PORT_DFNS is removed from include/asm-i386/serial.h and
include/asm-x86_64/serial.h. the serial8250_ports need to be probed late in
serial initializing stage. the console_init=>serial8250_console_init=>
register_console=>serial8250_console_setup will return -ENDEV, and console
ttyS0 can not be enabled at that time. need to wait till uart_add_one_port in
drivers/serial/serial_core.c to call register_console to get console ttyS0.
that is too late.
Make early_uart to use early_param, so uart console can be used earlier. Make
it to be bootconsole with CON_BOOT flag, so can use console handover feature.
and it will switch to corresponding normal serial console automatically.
new command line will be:
console=uart8250,io,0x3f8,9600n8
console=uart8250,mmio,0xff5e0000,115200n8
or
earlycon=uart8250,io,0x3f8,9600n8
earlycon=uart8250,mmio,0xff5e0000,115200n8
it will print in very early stage:
Early serial console at I/O port 0x3f8 (options '9600n8')
console [uart0] enabled
later for console it will print:
console handover: boot [uart0] -> real [ttyS0]
Signed-off-by: <yinghai.lu@sun.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Gerd Hoffmann <kraxel@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
add the init_idle_bootup_task() callback to the bootup thread,
unused at the moment. (CFS will use it to switch the scheduling
class of the boot thread to the idle class)
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Currently there is a circular reference between work queue initialization
and kthread initialization. This prevents the kthread infrastructure from
initializing until after work queues have been initialized.
We want the properties of tasks created with kthread_create to be as close
as possible to the init_task and to not be contaminated by user processes.
The later we start our kthreadd that creates these tasks the harder it is
to avoid contamination from user processes and the more of a mess we have
to clean up because the defaults have changed on us.
So this patch modifies the kthread support to not use work queues but to
instead use a simple list of structures, and to have kthreadd start from
init_task immediately after our kernel thread that execs /sbin/init.
By being a true child of init_task we only have to change those process
settings that we want to have different from init_task, such as our process
name, the cpus that are allowed, blocking all signals and setting SIGCHLD
to SIG_IGN so that all of our children are reaped automatically.
By being a true child of init_task we also naturally get our ppid set to 0
and do not wind up as a child of PID == 1. Ensuring that tasks generated
by kthread_create will not slow down the functioning of the wait family of
functions.
[akpm@linux-foundation.org: use interruptible sleeps]
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
enhance the initcall_debug boot option:
- measure the time the initcall took to execute and report
it in units of milliseconds.
- show the return code of initcalls (useful to see failures and
to make sure that an initcall hung)
[akpm@linux-foundation.org: fix printk warning]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The nr_cpu_ids value is currently only calculated in smp_init. However, it
may be needed before (SLUB needs it on kmem_cache_init!) and other kernel
components may also want to allocate dynamically sized per cpu array before
smp_init. So move the determination of possible cpus into sched_init()
where we already loop over all possible cpus early in boot.
Also initialize both nr_node_ids and nr_cpu_ids with the highest value they
could take. If we have accidental users before these values are determined
then the current valud of 0 may cause too small per cpu and per node arrays
to be allocated. If it is set to the maximum possible then we only waste
some memory for early boot users.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild: (38 commits)
kconfig: fix mconf segmentation fault
kbuild: enable use of code from a different dir
kconfig: error out if recursive dependencies are found
kbuild: scripts/basic/fixdep segfault on pathological string-o-death
kconfig: correct minor typo in Kconfig warning message.
kconfig: fix path to modules.txt in Kconfig help
usr/Kconfig: fix typo
kernel-doc: alphabetically-sorted entries in index.html of 'htmldocs'
kbuild: be more explicit on missing .config file
kbuild: clarify the creation of the LOCALVERSION_AUTO string.
kbuild: propagate errors from find in scripts/gen_initramfs_list.sh
kconfig: refer to qt3 if we cannot find qt libraries
kbuild: handle compressed cpio initramfs-es
kbuild: ignore section mismatch warning for references from .paravirtprobe to .init.text
kbuild: remove stale comment in modpost.c
kbuild/mkuboot.sh: allow spaces in CROSS_COMPILE
kbuild: fix make mrproper for Documentation/DocBook/man
kbuild: remove kconfig binaries during make mrproper
kconfig/menuconfig: do not hardcode '.config'
kbuild: override build timestamp & version
...
In init/main.c we have a reference from rest_init() to .init.text
which is intentional.
Rename the function 'init' to 'kernel_init' to make it a
kernel wide unique symbol and whitelist the reference.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Let's allow page-alignment in general for per-cpu data (wanted by Xen, and
Ingo suggested KVM as well).
Because larger alignments can use more room, we increase the max per-cpu
memory to 64k rather than 32k: it's getting a little tight.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
We frequently need the maximum number of possible processors in order to
allocate arrays for all processors. So far this was done using
highest_possible_processor_id(). However, we do need the number of
processors not the highest id. Moreover the number was so far dynamically
calculated on each invokation. The number of possible processors does not
change when the system is running. We can therefore calculate that number
once.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Frederik Deweerdt <frederik.deweerdt@gmail.com>
Cc: Neil Brown <neilb@suse.de>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
powerpc gets:
init/main.c: In function `do_basic_setup':
init/main.c:714: warning: implicit declaration of function `init_irq_proc'
but we cannot include linux/irq.h in generic code.
Fix it by moving the declaration into linux/interrupt.h instead.
And make sure all code that defines init_irq_proc() is including
linux/interrupt.h.
And nuke an ifdef-in-C
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With this change the sysctl inodes can be cached and nothing needs to be done
when removing a sysctl table.
For a cost of 2K code we will save about 4K of static tables (when we remove
de from ctl_table) and 70K in proc_dir_entries that we will not allocate, or
about half that on a 32bit arch.
The speed feels about the same, even though we can now cache the sysctl
dentries :(
We get the core advantage that we don't need to have a 1 to 1 mapping between
ctl table entries and proc files. Making it possible to have /proc/sys vary
depending on the namespace you are in. The currently merged namespaces don't
have an issue here but the network namespace under /proc/sys/net needs to have
different directories depending on which network adapters are visible. By
simply being a cache different directories being visible depending on who you
are is trivial to implement.
[akpm@osdl.org: fix uninitialised var]
[akpm@osdl.org: fix ARM build]
[bunk@stusta.de: make things static]
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
