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Commit Graph

210 Commits

Author SHA1 Message Date
Balbir Singh
cf475ad28a cgroups: add an owner to the mm_struct
Remove the mem_cgroup member from mm_struct and instead adds an owner.

This approach was suggested by Paul Menage.  The advantage of this approach
is that, once the mm->owner is known, using the subsystem id, the cgroup
can be determined.  It also allows several control groups that are
virtually grouped by mm_struct, to exist independent of the memory
controller i.e., without adding mem_cgroup's for each controller, to
mm_struct.

A new config option CONFIG_MM_OWNER is added and the memory resource
controller selects this config option.

This patch also adds cgroup callbacks to notify subsystems when mm->owner
changes.  The mm_cgroup_changed callback is called with the task_lock() of
the new task held and is called just prior to changing the mm->owner.

I am indebted to Paul Menage for the several reviews of this patchset and
helping me make it lighter and simpler.

This patch was tested on a powerpc box, it was compiled with both the
MM_OWNER config turned on and off.

After the thread group leader exits, it's moved to init_css_state by
cgroup_exit(), thus all future charges from runnings threads would be
redirected to the init_css_set's subsystem.

Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Sudhir Kumar <skumar@linux.vnet.ibm.com>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: Hirokazu Takahashi <taka@valinux.co.jp>
Cc: David Rientjes <rientjes@google.com>,
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Reviewed-by: Paul Menage <menage@google.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>
2008-04-29 08:06:10 -07:00
Serge E. Hallyn
08ce5f16ee cgroups: implement device whitelist
Implement a cgroup to track and enforce open and mknod restrictions on device
files.  A device cgroup associates a device access whitelist with each cgroup.
 A whitelist entry has 4 fields.  'type' is a (all), c (char), or b (block).
'all' means it applies to all types and all major and minor numbers.  Major
and minor are either an integer or * for all.  Access is a composition of r
(read), w (write), and m (mknod).

The root device cgroup starts with rwm to 'all'.  A child devcg gets a copy of
the parent.  Admins can then remove devices from the whitelist or add new
entries.  A child cgroup can never receive a device access which is denied its
parent.  However when a device access is removed from a parent it will not
also be removed from the child(ren).

An entry is added using devices.allow, and removed using
devices.deny.  For instance

	echo 'c 1:3 mr' > /cgroups/1/devices.allow

allows cgroup 1 to read and mknod the device usually known as
/dev/null.  Doing

	echo a > /cgroups/1/devices.deny

will remove the default 'a *:* mrw' entry.

CAP_SYS_ADMIN is needed to change permissions or move another task to a new
cgroup.  A cgroup may not be granted more permissions than the cgroup's parent
has.  Any task can move itself between cgroups.  This won't be sufficient, but
we can decide the best way to adequately restrict movement later.

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix may-be-used-uninitialized warning]
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Acked-by: James Morris <jmorris@namei.org>
Looks-good-to: Pavel Emelyanov <xemul@openvz.org>
Cc: Daniel Hokka Zakrisson <daniel@hozac.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:09 -07:00
Paul Menage
418d7d875c CGroup API files: make CGROUP_DEBUG default to off
The cgroup debug subsystem isn't generally useful for users.  It should
default to "n".

Signed-off-by: Paul Menage <menage@google.com>
Cc: "Li Zefan" <lizf@cn.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Paul Jackson <pj@sgi.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: "YAMAMOTO Takashi" <yamamoto@valinux.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:09 -07:00
Adrian Bunk
f17a32e97e let LOG_BUF_SHIFT default to 17
16 kB is often no longer enough for a normal boot of an UP system.

And even less when people e.g. use suspend.

17 seems to be a more reasonable default for current kernels on current
hardware (it's just the default, anyone who is memory limited can still lower
it).

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:01 -07:00
Linus Torvalds
e945e849e1 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6:
  sparc: video drivers: add facility level
  sparc: tcx.c make tcx_init and tcx_exit static
  sparc: ffb.c make ffb_init and ffb_exit static
  sparc: cg14.c make cg14_init and cg15_exit static
  sparc: bw2.c fix bw2_exit
  sparc64: Fix accidental syscall restart on child return from clone/fork/vfork.
  sparc64: Clean up handling of pt_regs trap type encoding.
  sparc: Remove old style signal frame support.
  sparc64: Kill bogus RT_ALIGNEDSZ macro from signal.c
  sparc: sunzilog.c remove unused argument
  sparc: fix drivers/video/tcx.c warning
  sparc64: Kill unused local ISA bus layer.
  input: Rewrite sparcspkr device probing.
  sparc64: Do not ignore 'pmu' device ranges.
  sparc64: Kill ISA_FLOPPY_WORKS code.
  sparc64: Kill CONFIG_SPARC32_COMPAT
  sparc64: Cleanups and corrections for arch/sparc64/Kconfig
  sparc64: Fix wedged irq regression.
2008-04-28 09:45:57 -07:00
Ingo Molnar
96fffeb4b4 make CC_OPTIMIZE_FOR_SIZE non-experimental
this option has been the default on a wide range of distributions
for a long time - time to make it non-experimental.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 09:42:46 -07:00
David S. Miller
09337f501e sparc64: Kill CONFIG_SPARC32_COMPAT
It's completely superfluous, CONFIG_COMPAT is sufficient.

What this used to be is an umbrella for enabling code shared
by all 32-bit compat binary support types.  But with the
removal of SunOS and Solaris support, the only one left is
Linux 32-bit ELF.

Update defconfig.

Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-26 21:41:19 -07:00
Viktor Radnai
b9b158fe1c sched: better rt-group documentation
Viktor was nice enough to enhance the document based on my replies to
his questions on the subject.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19 19:45:01 +02:00
Christoph Lameter
0f389ec630 slub: No need for per node slab counters if !SLUB_DEBUG
The per node counters are used mainly for showing data through the sysfs API.
If that API is not compiled in then there is no point in keeping track of this
data. Disable counters for the number of slabs and the number of total slabs
if !SLUB_DEBUG. Incrementing the per node counters is also accessing a
potentially contended cacheline so this could actually be a performance
benefit to embedded systems.

SLABINFO support is also affected. It now must depends on SLUB_DEBUG (which
is on by default).

Patch also avoids a check for a NULL kmem_cache_node pointer in new_slab()
if the system is not compiled with NUMA support.

[penberg@cs.helsinki.fi: fix oops and move ->nr_slabs into CONFIG_SLUB_DEBUG]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2008-04-14 18:53:02 +03:00
Paul E. McKenney
21bbb39c37 rcu: move PREEMPT_RCU config option back under PREEMPT
The original preemptible-RCU patch put the choice between classic and
preemptible RCU into kernel/Kconfig.preempt, which resulted in build failures
on machines not supporting CONFIG_PREEMPT.  This choice was therefore moved to
init/Kconfig, which worked, but placed the choice between classic and
preemptible RCU at the top level, a very obtuse choice indeed.

This patch changes from the Kconfig "choice" mechanism to a pair of booleans,
only one of which (CONFIG_PREEMPT_RCU) is user-visible, and is located in
kernel/Kconfig.preempt, where one would expect it to be.  The other
(CONFIG_CLASSIC_RCU) is in init/Kconfig so that it is available to all
architectures, hopefully avoiding build breakage.  Thanks to Roman Zippel for
suggesting this approach.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Cc: Josh Triplett <josh@freedesktop.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-10 18:01:20 -07:00
Linus Torvalds
2c6f2db13a Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-2.6:
  debugfs: fix sparse warnings
  Driver core: Fix cleanup when failing device_add().
  driver core: Remove dpm_sysfs_remove() from error path of device_add()
  PM: fix new mutex-locking bug in the PM core
  PM: Do not acquire device semaphores upfront during suspend
  kobject: properly initialize ksets
  sysfs: CONFIG_SYSFS_DEPRECATED fix
  driver core: fix up Kconfig text for CONFIG_SYSFS_DEPRECATED
2008-03-04 16:37:35 -08:00
Balbir Singh
00f0b8259e Memory controller: rename to Memory Resource Controller
Rename Memory Controller to Memory Resource Controller.  Reflect the same
changes in the CONFIG definition for the Memory Resource Controller.  Group
together the config options for Resource Counters and Memory Resource
Controller.

Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-04 16:35:12 -08:00
Ingo Molnar
d47846c586 sysfs: CONFIG_SYSFS_DEPRECATED fix
CONFIG_SYSFS_DEPRECATED=y changed its meaning recently and causes
regressions in working setups that had SYSFS_DEPRECATED disabled.

so rename it to SYSFS_DEPRECATED_V2 so that testers pick up the new
default via 'make oldconfig', even if their old .config's disabled
CONFIG_SYSFS_DEPRECATED ...

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-03-04 14:47:04 -08:00
Greg Kroah-Hartman
024440d2ec driver core: fix up Kconfig text for CONFIG_SYSFS_DEPRECATED
As things get moved into this config option, the hard date of 2006 does
not work anymore, so update the text to be more descriptive.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-03-04 14:47:04 -08:00
Andi Kleen
0835ab53ea cgroup memory controller: document huge memory/cache overhead in Kconfig
Document huge memory/cache overhead of memory controller in Kconfig

I was a little surprised that 2.6.25-rc* increased struct page for the
memory controller.  At least on many x86-64 machines it will not fit into a
single cache line now anymore and also costs considerable amounts of RAM.
At earlier review I remembered asking for a external data structure for
this.

It's also quite unobvious that a innocent looking Kconfig option with a
single line Kconfig description has such a negative effect.

This patch attempts to document these disadvantages at least so that users
configuring their kernel can make a informed decision.

Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Balbir Singh <balbir@in.ibm.com>
Acked-by: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-23 17:12:16 -08:00
Peter Zijlstra
052f1dc7eb sched: rt-group: make rt groups scheduling configurable
Make the rt group scheduler compile time configurable.
Keep it experimental for now.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-13 15:45:40 +01:00
Ingo Molnar
166124fde9 brk: help text typo fix
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-02-09 23:24:09 +01:00
Pavel Emelyanov
74bd59bb39 namespaces: cleanup the code managed with PID_NS option
Just like with the user namespaces, move the namespace management code into
the separate .c file and mark the (already existing) PID_NS option as "depend
on NAMESPACES"

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:23 -08:00
Pavel Emelyanov
aee16ce73c namespaces: cleanup the code managed with the USER_NS option
Make the user_namespace.o compilation depend on this option and move the
init_user_ns into user.c file to make the kernel compile and work without the
namespaces support.  This make the user namespace code be organized similar to
other namespaces'.

Also mask the USER_NS option as "depend on NAMESPACES".

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:23 -08:00
Pavel Emelyanov
ae5e1b22f1 namespaces: move the IPC namespace under IPC_NS option
Currently the IPC namespace management code is spread over the ipc/*.c files.
I moved this code into ipc/namespace.c file which is compiled out when needed.

The linux/ipc_namespace.h file is used to store the prototypes of the
functions in namespace.c and the stubs for NAMESPACES=n case.  This is done
so, because the stub for copy_ipc_namespace requires the knowledge of the
CLONE_NEWIPC flag, which is in sched.h.  But the linux/ipc.h file itself in
included into many many .c files via the sys.h->sem.h sequence so adding the
sched.h into it will make all these .c depend on sched.h which is not that
good.  On the other hand the knowledge about the namespaces stuff is required
in 4 .c files only.

Besides, this patch compiles out some auxiliary functions from ipc/sem.c,
msg.c and shm.c files.  It turned out that moving these functions into
namespaces.c is not that easy because they use many other calls and macros
from the original file.  Moving them would make this patch complicated.  On
the other hand all these functions can be consolidated, so I will send a
separate patch doing this a bit later.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:23 -08:00
Pavel Emelyanov
58bfdd6dee namespaces: move the UTS namespace under UTS_NS option
Currently all the namespace management code is in the kernel/utsname.c file,
so just compile it out and make stubs in the appropriate header.

The init namespace itself is in init/version.c and is in the kernel all the
time.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:23 -08:00
Pavel Emelyanov
c5289a6949 namespaces: add the NAMESPACES config option
The option is selectable if EMBEDDED is chosen only.  When the EMBEDDED is off
namespaces will be on.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:23 -08:00
Balbir Singh
8cdea7c054 Memory controller: cgroups setup
Setup the memory cgroup and add basic hooks and controls to integrate
and work with the cgroup.

Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Paul Menage <menage@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: David Rientjes <rientjes@google.com>
Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-07 08:42:18 -08:00
Pavel Emelianov
e552b66170 Memory controller: resource counters
With fixes from David Rientjes <rientjes@google.com>

Introduce generic structures and routines for resource accounting.

Each resource accounting cgroup is supposed to aggregate it,
cgroup_subsystem_state and its resource-specific members within.

Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Paul Menage <menage@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-07 08:42:18 -08:00
Ingo Molnar
32a932332c brk randomization: introduce CONFIG_COMPAT_BRK
based on similar patch from: Pavel Machek <pavel@ucw.cz>

Introduce CONFIG_COMPAT_BRK. If disabled then the kernel is free
(but not obliged to) randomize the brk area.

Heap randomization breaks ancient binaries, so we keep COMPAT_BRK
enabled by default.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-06 22:39:44 +01:00
Matt Mackall
3729145821 slob: correct Kconfig description
Signed-off-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05 09:44:19 -08:00
Matt Mackall
1e88328111 maps4: make page monitoring /proc file optional
Make /proc/ page monitoring configurable

This puts the following files under an embedded config option:

/proc/pid/clear_refs
/proc/pid/smaps
/proc/pid/pagemap
/proc/kpagecount
/proc/kpageflags

[akpm@linux-foundation.org: Kconfig fix]
Signed-off-by: Matt Mackall <mpm@selenic.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05 09:44:17 -08:00
Davide Libenzi
f79c343e2e timerfd: un-break CONFIG_TIMERFD
Remove the broken status to CONFIG_TIMERFD.

Signed-off-by: Davide Libenzi <davidel@xmailserver.org>
Cc: Michael Kerrisk <mtk-manpages@gmx.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05 09:44:07 -08:00
Mathieu Desnoyers
125e564582 Move Kconfig.instrumentation to arch/Kconfig and init/Kconfig
Move the instrumentation Kconfig to

arch/Kconfig for architecture dependent options
  - oprofile
  - kprobes

and

init/Kconfig for architecture independent options
  - profiling
  - markers

Remove the "Instrumentation Support" menu. Everything moves to "General setup".
Delete the kernel/Kconfig.instrumentation file.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2008-02-03 08:58:08 +01:00
Mathieu Desnoyers
fb32e03fdc Create arch/Kconfig
Puts the content of arch/Kconfig in the "General setup" menu.

Linus:

> Should it come with a re-duplication of it's content into each
> architecture, which was the case previously ? The oprofile and kprobes
> menu entries were litteraly cut and pasted from one architecture to
> another. Should we put its content in init/Kconfig then ?

I don't think it's a good idea to go back to making it per-architecture,
although that extensive "depends on <list-of-archiectures-here>" might
indicate that there certainly is room for cleanup there.

And I don't think it's wrong keeping it in kernel/Kconfig.xyz per se, I
just think it's wrong to (a) lump the code together when it really doesn't
necessarily need to and (b) show it to users as some kind of choice that
is tied together (whether it then has common code or not).

On the per-architecture side, I do think it would be better to *not* have
internal architecture knowledge in a generic file, and as such a line like

        depends on X86_32 || IA64 || PPC || S390 || SPARC64 || X86_64 || AVR32

really shouldn't exist in a file like kernel/Kconfig.instrumentation.

It would be much better to do

        depends on ARCH_SUPPORTS_KPROBES

in that generic file, and then architectures that do support it would just
have a

        bool ARCH_SUPPORTS_KPROBES
                default y

in *their* architecture files. That would seem to be much more logical,
and is readable both for arch maintainers *and* for people who have no
clue - and don't care - about which architecture is supposed to support
which interface...

Sam Ravnborg:

Stuff it into a new file: arch/Kconfig
We can then extend this file to include all the 'trailing'
Kconfig things that are anyway equal for all ARCHs.

But it should be kept clean - so if we introduce such a file
then we should use ARCH_HAS_whatever in the arch specific Kconfig
files to enable stuff that is not shared.

[...]

The above suggestion is actually not exactly the best way to do it...
First the naming..
A quick grep shows following usage today (in Kconfig files)
ARCH_HAS        51
ARCH_SUPPORTS   4
HAVE_ARCH       7

ARCH_HAS is the clear winner.

In the common Kconfig file do:

config FOO
        depends on ARCH_HAS_FOO
        bool "bla bla"

config ARCH_HAS_FOO
        def_bool n

In the arch specific Kconfig file in a suitable place do:

config SUITABLE_OPTION
        select ARCH_HAS_FOO

The naming of ARCH_HAS_ is fixed and shall be:
ARCH_HAS_<config option it will enable>

Only a single line added pr. architecture.
And we will end up with a (maybe even commented) list of trivial selects.

- Yet another update :

Moving to HAVE_* now.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2008-02-03 08:58:07 +01:00
Paul E. McKenney
095031052b RCU: add help text for "RCU implementation type"
This patch supplies help text for the "RCU implementation type"
kernel configuration choice.

Reported-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-31 22:45:22 +01:00
Roman Zippel
80daa56008 kconfig: use environment option
Use the environment option to provide the ARCH symbol
and the KERNELVERSION symbol.

Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2008-01-28 23:14:39 +01:00
Yuichi Nakamura
1322b9def9 sh: syscall audit support.
Support syscall auditing..

Signed-off-by: Yuichi Nakamura <ynakam@hitachisoft.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2008-01-28 13:18:57 +09:00
Paul E. McKenney
e260be673a Preempt-RCU: implementation
This patch implements a new version of RCU which allows its read-side
critical sections to be preempted. It uses a set of counter pairs
to keep track of the read-side critical sections and flips them
when all tasks exit read-side critical section. The details
of this implementation can be found in this paper -

	http://www.rdrop.com/users/paulmck/RCU/OLSrtRCU.2006.08.11a.pdf

and the article-

	http://lwn.net/Articles/253651/

This patch was developed as a part of the -rt kernel development and
meant to provide better latencies when read-side critical sections of
RCU don't disable preemption.  As a consequence of keeping track of RCU
readers, the readers have a slight overhead (optimizations in the paper).
This implementation co-exists with the "classic" RCU implementations
and can be switched to at compiler.

Also includes RCU tracing summarized in debugfs.

[ akpm@linux-foundation.org: build fixes on non-preempt architectures ]

Signed-off-by: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Dipankar Sarma <dipankar@in.ibm.com>
Signed-off-by: Paul E. McKenney <paulmck@us.ibm.com>
Reviewed-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25 21:08:24 +01:00
Randy Dunlap
9148fe8767 sysfs: make SYSFS_DEPRECATED depend on SYSFS
Make SYSFS_DEPRECATED depend on SYSFS since files that check
CONFIG_SYSFS_DEPRECATED don't check for CONFIG_SYSFS first.
Also don't prompt user about SYSFS_DEPRECATED if SYSFS=n.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:41 -08:00
Linus Torvalds
158a962422 Unify /proc/slabinfo configuration
Both SLUB and SLAB really did almost exactly the same thing for
/proc/slabinfo setup, using duplicate code and per-allocator #ifdef's.

This just creates a common CONFIG_SLABINFO that is enabled by both SLUB
and SLAB, and shares all the setup code.  Maybe SLOB will want this some
day too.

Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-02 13:04:48 -08:00
Srivatsa Vaddagiri
d842de871c sched: cpu accounting controller (V2)
Commit cfb5285660 removed a useful feature for
us, which provided a cpu accounting resource controller.  This feature would be
useful if someone wants to group tasks only for accounting purpose and doesnt
really want to exercise any control over their cpu consumption.

The patch below reintroduces the feature. It is based on Paul Menage's
original patch (Commit 62d0df6406), with
these differences:

        - Removed load average information. I felt it needs more thought (esp
	  to deal with SMP and virtualized platforms) and can be added for
	  2.6.25 after more discussions.
        - Convert group cpu usage to be nanosecond accurate (as rest of the cfs
	  stats are) and invoke cpuacct_charge() from the respective scheduler
	  classes
	- Make accounting scalable on SMP systems by splitting the usage
	  counter to be per-cpu
	- Move the code from kernel/cpu_acct.c to kernel/sched.c (since the
	  code is not big enough to warrant a new file and also this rightly
	  needs to live inside the scheduler. Also things like accessing
	  rq->lock while reading cpu usage becomes easier if the code lived in
	  kernel/sched.c)

The patch also modifies the cpu controller not to provide the same accounting
information.

Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com>

 Tested the patches on top of 2.6.24-rc3. The patches work fine. Ran
 some simple tests like cpuspin (spin on the cpu), ran several tasks in
 the same group and timed them. Compared their time stamps with
 cpuacct.usage.

Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-12-02 20:04:49 +01:00
Mike Frysinger
529a73fbae Blackfin arch: punt CONFIG_BFIN -- we already have CONFIG_BLACKFIN
Signed-off-by: Mike Frysinger <michael.frysinger@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
2007-11-23 14:28:44 +08:00
Eric W. Biederman
57d5f66b86 pidns: Place under CONFIG_EXPERIMENTAL
This is my trivial patch to swat innumerable little bugs with a single
blow.

After some intensive review (my apologies for not having gotten to this
sooner) what we have looks like a good base to build on with the current
pid namespace code but it is not complete, and it is still much to simple
to find issues where the kernel does the wrong thing outside of the initial
pid namespace.

Until the dust settles and we are certain we have the ABI and the
implementation is as correct as humanly possible let's keep process ID
namespaces behind CONFIG_EXPERIMENTAL.

Allowing us the option of fixing any ABI or other bugs we find as long as
they are minor.

Allowing users of the kernel to avoid those bugs simply by ensuring their
kernel does not have support for multiple pid namespaces.

[akpm@linux-foundation.org: coding-style cleanups]
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Adrian Bunk <bunk@kernel.org>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Kir Kolyshkin <kir@swsoft.com>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-11-14 18:45:43 -08:00
Andrew Morton
cfb5285660 revert "Task Control Groups: example CPU accounting subsystem"
Revert 62d0df6406.

This was originally intended as a simple initial example of how to create a
control groups subsystem; it wasn't intended for mainline, but I didn't make
this clear enough to Andrew.

The CFS cgroup subsystem now has better functionality for the per-cgroup usage
accounting (based directly on CFS stats) than the "usage" status file in this
patch, and the "load" status file is rather simplistic - although having a
per-cgroup load average report would be a useful feature, I don't believe this
patch actually provides it.  If it gets into the final 2.6.24 we'd probably
have to support this interface for ever.

Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-11-14 18:45:40 -08:00
Ingo Molnar
8ef93cf114 sched: mark CONFIG_FAIR_GROUP_SCHED as !EXPERIMENTAL
mark CONFIG_FAIR_GROUP_SCHED as !EXPERIMENTAL. All bugs have been
fixed and it's perfect ;-)

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-24 18:23:51 +02:00
Al Viro
74c3cbe33b [PATCH] audit: watching subtrees
New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is.  Limitations:
	* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
	* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
	* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there.  New command
tells audit to recalculate the trees, trimming such sources of false
positives.

Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-10-21 02:37:45 -04:00
Srivatsa Vaddagiri
68318b8e0b Hook up group scheduler with control groups
Enable "cgroup" (formerly containers) based fair group scheduling.  This
will let administrator create arbitrary groups of tasks (using "cgroup"
pseudo filesystem) and control their cpu bandwidth usage.

[akpm@linux-foundation.org: fix cpp condition]
Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Paul Menage <menage@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 11:53:51 -07:00
Serge E. Hallyn
858d72ead4 cgroups: implement namespace tracking subsystem
When a task enters a new namespace via a clone() or unshare(), a new cgroup
is created and the task moves into it.

This version names cgroups which are automatically created using
cgroup_clone() as "node_<pid>" where pid is the pid of the unsharing or
cloned process.  (Thanks Pavel for the idea) This is safe because if the
process unshares again, it will create

	/cgroups/(...)/node_<pid>/node_<pid>

The only possibilities (AFAICT) for a -EEXIST on unshare are

	1. pid wraparound
	2. a process fails an unshare, then tries again.

Case 1 is unlikely enough that I ignore it (at least for now).  In case 2, the
node_<pid> will be empty and can be rmdir'ed to make the subsequent unshare()
succeed.

Changelog:
	Name cloned cgroups as "node_<pid>".

[clg@fr.ibm.com: fix order of cgroup subsystems in init/Kconfig]
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: 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>
2007-10-19 11:53:37 -07:00
Paul Menage
006cb99200 Task Control Groups: simple task cgroup debug info subsystem
This example subsystem exports debugging information as an aid to diagnosing
refcount leaks, etc, in the cgroup framework.

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>
2007-10-19 11:53:36 -07:00
Paul Menage
62d0df6406 Task Control Groups: example CPU accounting subsystem
This example demonstrates how to use the generic cgroup subsystem for a
simple resource tracker that counts, for the processes in a cgroup, the
total CPU time used and the %CPU used in the last complete 10 second interval.

Portions contributed by Balbir Singh <balbir@in.ibm.com>

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>
2007-10-19 11:53:36 -07:00
Paul Menage
8793d854ed Task Control Groups: make cpusets a client of cgroups
Remove the filesystem support logic from the cpusets system and makes cpusets
a cgroup subsystem

The "cpuset" filesystem becomes a dummy filesystem; attempts to mount it get
passed through to the cgroup filesystem with the appropriate options to
emulate the old cpuset filesystem behaviour.

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>
2007-10-19 11:53:36 -07:00
Paul Menage
ddbcc7e8e5 Task Control Groups: basic task cgroup framework
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>
2007-10-19 11:53:36 -07:00
Avi Kivity
e98c320291 Move PREEMPT_NOTIFIERS into an always-included Kconfig
Kconfig.preempt is not included on some archs (for example, m68k).  On those
archs, the Kconfig machinery complains that KVM selects an undefined symbol
PREEMPT_NOTIFIERS (which lives in Kconfig.preempt).

So move the offending symbol into a Kconfig file which is included by
everyone.

Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-17 08:42:55 -07:00
Mel Gorman
ac0e5b7a6b remove PAGE_GROUP_BY_MOBILITY
Grouping pages by mobility can be disabled at compile-time. This was
considered undesirable by a number of people. However, in the current stack of
patches, it is not a simple case of just dropping the configurable patch as it
would cause merge conflicts.  This patch backs out the configuration option.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:43:00 -07:00
Mel Gorman
b92a6edd4b Add a configure option to group pages by mobility
The grouping mechanism has some memory overhead and a more complex allocation
path.  This patch allows the strategy to be disabled for small memory systems
or if it is known the workload is suffering because of the strategy.  It also
acts to show where the page groupings strategy interacts with the standard
buddy allocator.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Joel Schopp <jschopp@austin.ibm.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16 09:42:59 -07:00
Srivatsa Vaddagiri
fb615581c7 sched: group scheduler, fix coding style issues
Fix coding style issues reported by Randy Dunlap and others

Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:12 +02:00
Ingo Molnar
de8d585a12 sched: enable CONFIG_FAIR_GROUP_SCHED=y by default
enable CONFIG_FAIR_GROUP_SCHED=y by default.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:09 +02:00
Ingo Molnar
7ed2be459b sched: fair-group sched, cleanups
fair-group sched, cleanups.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:09 +02:00
Srivatsa Vaddagiri
24e377a832 sched: add fair-user scheduler
Enable user-id based fair group scheduling. This is useful for anyone
who wants to test the group scheduler w/o having to enable
CONFIG_CGROUPS.

A separate scheduling group (i.e struct task_grp) is automatically created for 
every new user added to the system. Upon uid change for a task, it is made to 
move to the corresponding scheduling group.

A /proc tunable (/proc/root_user_share) is also provided to tune root
user's quota of cpu bandwidth.

Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:09 +02:00
Srivatsa Vaddagiri
9b5b77512d sched: clean up code under CONFIG_FAIR_GROUP_SCHED
With the view of supporting user-id based fair scheduling (and not just
container-based fair scheduling), this patch renames several functions
and makes them independent of whether they are being used for container
or user-id based fair scheduling.

Also fix a problem reported by KAMEZAWA Hiroyuki (wrt allocating
less-sized array for tg->cfs_rq[] and tf->se[]).

Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
2007-10-15 17:00:09 +02:00
Srivatsa Vaddagiri
29f59db3a7 sched: group-scheduler core
Add interface to control cpu bandwidth allocation to task-groups.

(not yet configurable, due to missing CONFIG_CONTAINERS)

Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2007-10-15 17:00:07 +02:00
Andrew Morton
e42601973b disable sys_timerfd() for 2.6.23
There is still some confusion and disagreement over what this interface should
actually do.  So it is best that we disable it in 2.6.23 until we get that
fully sorted out.

(sys_timerfd() was present in 2.6.22 but it was apparently broken, so here we
assume that nobody is using it yet).

Cc: Michael Kerrisk <mtk-manpages@gmx.net>
Cc: Davide Libenzi <davidel@xmailserver.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-09-19 11:24:18 -07:00
Al Boldi
ff0cfc66cd Kconfig: remove top level menu "Code maturity level options"
Remove the top level menu "Code maturity level options", and moves its
options into menu "General setup".

This makes Kconfig less cluttered and easier to setup.

Signed-off-by: Al Boldi <a1426z@gawab.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-31 15:39:43 -07:00
Adrian Bunk
448e3cee83 ANON_INODES shouldn't be user visible
There doesn't seem to be a good reason for ANON_INODES being
an user visible option.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Acked-by: Davide Libenzi <davidel@xmailserver.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-31 15:39:42 -07:00
Paul Mundt
32582fa460 sh: Add sh to the CC_OPTIMIZE_FOR_SIZE dependencies.
Presently we only use this with CONFIG_EXPERIMENTAL, but it is
something that can be supported commonly.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2007-07-26 15:37:44 +09:00
Christoph Lameter
a0acd82080 Make SLUB the default allocator
There are some reports that 2.6.22 has SLUB as the default. Not
true!

This will make SLUB the default for 2.6.23.

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>
2007-07-17 10:23:02 -07:00
Cedric Le Goater
acce292c82 user namespace: add the framework
Basically, it will allow a process to unshare its user_struct table,
resetting at the same time its own user_struct and all the associated
accounting.

A new root user (uid == 0) is added to the user namespace upon creation.
Such root users have full privileges and it seems that theses privileges
should be controlled through some means (process capabilities ?)

The unshare is not included in this patch.

Changes since [try #4]:
	- Updated get_user_ns and put_user_ns to accept NULL, and
	  get_user_ns to return the namespace.

Changes since [try #3]:
	- moved struct user_namespace to files user_namespace.{c,h}

Changes since [try #2]:
	- removed struct user_namespace* argument from find_user()

Changes since [try #1]:
	- removed struct user_namespace* argument from find_user()
	- added a root_user per user namespace

Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Acked-by: Pavel Emelianov <xemul@openvz.org>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <jmorris@namei.org>
Cc: Andrew Morgan <agm@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:47 -07:00
Cedric Le Goater
7d69a1f4a7 remove CONFIG_UTS_NS and CONFIG_IPC_NS
CONFIG_UTS_NS and CONFIG_IPC_NS have very little value as they only
deactivate the unshare of the uts and ipc namespaces and do not improve
performance.

Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Acked-by: "Serge E. Hallyn" <serue@us.ibm.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Pavel Emelianov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:47 -07:00
Jan Engelhardt
66da573320 Use menuconfig objects II - module menu
Change menuconfig objects from "menu, config" into "menuconfig" so that the
user can disable the whole feature without entering its menu first.

Signed-off-by: Jan Engelhardt <jengelh@gmx.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:40 -07:00
Paul Mundt
84a01c2f8e slob: sparsemem support
Currently slob is disabled if we're using sparsemem, due to an earlier
patch from Goto-san.  Slob and static sparsemem work without any trouble as
it is, and the only hiccup is a missing slab_is_available() in the case of
sparsemem extreme.  With this, we're rid of the last set of restrictions
for slob usage.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Matt Mackall <mpm@selenic.com>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:36 -07:00
Jan Engelhardt
5f5c926e3c block/Kconfig already has its own "menuconfig" so remove these
"menu, endmenu" that did not get cleaned up in the block patch
[ http://lkml.org/lkml/2007/4/10/251 ]

Signed-off-by: Jan Engelhardt <jengelh@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-07-10 13:43:28 +02:00
Christoph Lameter
9fbf09a09e SLUB: Remove depends on EXPERIMENTAL and !ARCH_USES_SLAB_PAGE_STRUCT
No arch sets ARCH_USES_SLAB_PAGE_STRUCT anymore.

Remove the experimental dependency as well since we want to have it as
a real alternative to SLAB.

It all comes down to killing a single line from init/Kconfig.

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>
2007-05-17 05:23:03 -07:00
Nick Piggin
afc0cedbe9 slob: implement RCU freeing
The SLOB allocator should implement SLAB_DESTROY_BY_RCU correctly, because
even on UP, RCU freeing semantics are not equivalent to simply freeing
immediately.  This also allows SLOB to be used on SMP.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-17 05:23:02 -07:00
Davide Libenzi
e1ad7468c7 signal/timer/event: eventfd core
This is a very simple and light file descriptor, that can be used as event
wait/dispatch by userspace (both wait and dispatch) and by the kernel
(dispatch only).  It can be used instead of pipe(2) in all cases where those
would simply be used to signal events.  Their kernel overhead is much lower
than pipes, and they do not consume two fds.  When used in the kernel, it can
offer an fd-bridge to enable, for example, functionalities like KAIO or
syslets/threadlets to signal to an fd the completion of certain operations.
But more in general, an eventfd can be used by the kernel to signal readiness,
in a POSIX poll/select way, of interfaces that would otherwise be incompatible
with it.  The API is:

int eventfd(unsigned int count);

The eventfd API accepts an initial "count" parameter, and returns an eventfd
fd.  It supports poll(2) (POLLIN, POLLOUT, POLLERR), read(2) and write(2).

The POLLIN flag is raised when the internal counter is greater than zero.

The POLLOUT flag is raised when at least a value of "1" can be written to the
internal counter.

The POLLERR flag is raised when an overflow in the counter value is detected.

The write(2) operation can never overflow the counter, since it blocks (unless
O_NONBLOCK is set, in which case -EAGAIN is returned).

But the eventfd_signal() function can do it, since it's supposed to not sleep
during its operation.

The read(2) function reads the __u64 counter value, and reset the internal
value to zero.  If the value read is equal to (__u64) -1, an overflow happened
on the internal counter (due to 2^64 eventfd_signal() posts that has never
been retired - unlickely, but possible).

The write(2) call writes an __u64 count value, and adds it to the current
counter.  The eventfd fd supports O_NONBLOCK also.

On the kernel side, we have:

struct file *eventfd_fget(int fd);
int eventfd_signal(struct file *file, unsigned int n);

The eventfd_fget() should be called to get a struct file* from an eventfd fd
(this is an fget() + check of f_op being an eventfd fops pointer).

The kernel can then call eventfd_signal() every time it wants to post an event
to userspace.  The eventfd_signal() function can be called from any context.
An eventfd() simple test and bench is available here:

http://www.xmailserver.org/eventfd-bench.c

This is the eventfd-based version of pipetest-4 (pipe(2) based):

http://www.xmailserver.org/pipetest-4.c

Not that performance matters much in the eventfd case, but eventfd-bench
shows almost as double as performance than pipetest-4.

[akpm@linux-foundation.org: fix i386 build]
[akpm@linux-foundation.org: add sys_eventfd to sys_ni.c]
Signed-off-by: Davide Libenzi <davidel@xmailserver.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-11 08:29:36 -07:00
Davide Libenzi
b215e28399 signal/timer/event: timerfd core
This patch introduces a new system call for timers events delivered though
file descriptors.  This allows timer event to be used with standard POSIX
poll(2), select(2) and read(2).  As a consequence of supporting the Linux
f_op->poll subsystem, they can be used with epoll(2) too.

The system call is defined as:

int timerfd(int ufd, int clockid, int flags, const struct itimerspec *utmr);

The "ufd" parameter allows for re-use (re-programming) of an existing timerfd
w/out going through the close/open cycle (same as signalfd).  If "ufd" is -1,
s new file descriptor will be created, otherwise the existing "ufd" will be
re-programmed.

The "clockid" parameter is either CLOCK_MONOTONIC or CLOCK_REALTIME.  The time
specified in the "utmr->it_value" parameter is the expiry time for the timer.

If the TFD_TIMER_ABSTIME flag is set in "flags", this is an absolute time,
otherwise it's a relative time.

If the time specified in the "utmr->it_interval" is not zero (.tv_sec == 0,
tv_nsec == 0), this is the period at which the following ticks should be
generated.

The "utmr->it_interval" should be set to zero if only one tick is requested.
Setting the "utmr->it_value" to zero will disable the timer, or will create a
timerfd without the timer enabled.

The function returns the new (or same, in case "ufd" is a valid timerfd
descriptor) file, or -1 in case of error.

As stated before, the timerfd file descriptor supports poll(2), select(2) and
epoll(2).  When a timer event happened on the timerfd, a POLLIN mask will be
returned.

The read(2) call can be used, and it will return a u32 variable holding the
number of "ticks" that happened on the interface since the last call to
read(2).  The read(2) call supportes the O_NONBLOCK flag too, and EAGAIN will
be returned if no ticks happened.

A quick test program, shows timerfd working correctly on my amd64 box:

http://www.xmailserver.org/timerfd-test.c

[akpm@linux-foundation.org: add sys_timerfd to sys_ni.c]
Signed-off-by: Davide Libenzi <davidel@xmailserver.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-11 08:29:36 -07:00
Davide Libenzi
fba2afaaec signal/timer/event: signalfd core
This patch series implements the new signalfd() system call.

I took part of the original Linus code (and you know how badly it can be
broken :), and I added even more breakage ;) Signals are fetched from the same
signal queue used by the process, so signalfd will compete with standard
kernel delivery in dequeue_signal().  If you want to reliably fetch signals on
the signalfd file, you need to block them with sigprocmask(SIG_BLOCK).  This
seems to be working fine on my Dual Opteron machine.  I made a quick test
program for it:

http://www.xmailserver.org/signafd-test.c

The signalfd() system call implements signal delivery into a file descriptor
receiver.  The signalfd file descriptor if created with the following API:

int signalfd(int ufd, const sigset_t *mask, size_t masksize);

The "ufd" parameter allows to change an existing signalfd sigmask, w/out going
to close/create cycle (Linus idea).  Use "ufd" == -1 if you want a brand new
signalfd file.

The "mask" allows to specify the signal mask of signals that we are interested
in.  The "masksize" parameter is the size of "mask".

The signalfd fd supports the poll(2) and read(2) system calls.  The poll(2)
will return POLLIN when signals are available to be dequeued.  As a direct
consequence of supporting the Linux poll subsystem, the signalfd fd can use
used together with epoll(2) too.

The read(2) system call will return a "struct signalfd_siginfo" structure in
the userspace supplied buffer.  The return value is the number of bytes copied
in the supplied buffer, or -1 in case of error.  The read(2) call can also
return 0, in case the sighand structure to which the signalfd was attached,
has been orphaned.  The O_NONBLOCK flag is also supported, and read(2) will
return -EAGAIN in case no signal is available.

If the size of the buffer passed to read(2) is lower than sizeof(struct
signalfd_siginfo), -EINVAL is returned.  A read from the signalfd can also
return -ERESTARTSYS in case a signal hits the process.  The format of the
struct signalfd_siginfo is, and the valid fields depends of the (->code &
__SI_MASK) value, in the same way a struct siginfo would:

struct signalfd_siginfo {
	__u32 signo;	/* si_signo */
	__s32 err;	/* si_errno */
	__s32 code;	/* si_code */
	__u32 pid;	/* si_pid */
	__u32 uid;	/* si_uid */
	__s32 fd;	/* si_fd */
	__u32 tid;	/* si_fd */
	__u32 band;	/* si_band */
	__u32 overrun;	/* si_overrun */
	__u32 trapno;	/* si_trapno */
	__s32 status;	/* si_status */
	__s32 svint;	/* si_int */
	__u64 svptr;	/* si_ptr */
	__u64 utime;	/* si_utime */
	__u64 stime;	/* si_stime */
	__u64 addr;	/* si_addr */
};

[akpm@linux-foundation.org: fix signalfd_copyinfo() on i386]
Signed-off-by: Davide Libenzi <davidel@xmailserver.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-11 08:29:36 -07:00
Davide Libenzi
5dc8bf8132 signal/timer/event fds: anonymous inode source
This patch add an anonymous inode source, to be used for files that need
and inode only in order to create a file*. We do not care of having an
inode for each file, and we do not even care of having different names in
the associated dentries (dentry names will be same for classes of file*).
This allow code reuse, and will be used by epoll, signalfd and timerfd
(and whatever else there'll be).

Signed-off-by: Davide Libenzi <davidel@xmailserver.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-11 08:29:36 -07:00
Christoph Lameter
d4751a2797 SLUB: SLUB_DEBUG must depend on SLUB
Otherwise people get asked about SLUB_DEBUG even if they have another
slab allocator enabled.

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>
2007-05-10 09:26:53 -07:00
Linus Torvalds
9a9136e270 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivial
* git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivial: (25 commits)
  sound: convert "sound" subdirectory to UTF-8
  MAINTAINERS: Add cxacru website/mailing list
  include files: convert "include" subdirectory to UTF-8
  general: convert "kernel" subdirectory to UTF-8
  documentation: convert the Documentation directory to UTF-8
  Convert the toplevel files CREDITS and MAINTAINERS to UTF-8.
  remove broken URLs from net drivers' output
  Magic number prefix consistency change to Documentation/magic-number.txt
  trivial: s/i_sem /i_mutex/
  fix file specification in comments
  drivers/base/platform.c: fix small typo in doc
  misc doc and kconfig typos
  Remove obsolete fat_cvf help text
  Fix occurrences of "the the "
  Fix minor typoes in kernel/module.c
  Kconfig: Remove reference to external mqueue library
  Kconfig: A couple of grammatical fixes in arch/i386/Kconfig
  Correct comments in genrtc.c to refer to correct /proc file.
  Fix more "deprecated" spellos.
  Fix "deprecated" typoes.
  ...

Fix trivial comment conflict in kernel/relay.c.
2007-05-09 12:54:17 -07:00
Christoph Lameter
34013886ef Fix spellings of slab allocator section in init/Kconfig
Fix some of the spelling issues. Fix sentences. Discourage SLOB use
since SLUB can pack objects denser.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:46 -07:00
Christoph Lameter
41ecc55b8a SLUB: add CONFIG_SLUB_DEBUG
CONFIG_SLUB_DEBUG can be used to switch off the debugging and sysfs components
of SLUB.  Thus SLUB will be able to replace SLOB.  SLUB can arrange objects in
a denser way than SLOB and the code size should be minimal without debugging
and sysfs support.

Note that CONFIG_SLUB_DEBUG is materially different from CONFIG_SLAB_DEBUG.
CONFIG_SLAB_DEBUG is used to enable slab debugging in SLAB.  SLUB enables
debugging via a boot parameter.  SLUB debug code should always be present.

CONFIG_SLUB_DEBUG can be modified in the embedded config section.

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>
2007-05-09 12:30:45 -07:00
Robert P. J. Day
b0e3765040 Kconfig: Remove reference to external mqueue library
Remove the reference to an external mqueue library since that was
merged into glibc in 2004.

Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2007-05-09 07:25:13 +02:00
David Sterba
3dde6ad8fc Fix trivial typos in Kconfig* files
Fix several typos in help text in Kconfig* files.

Signed-off-by: David Sterba <dave@jikos.cz>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2007-05-09 07:12:20 +02:00
Alistair John Strachan
794543a236 Move LOG_BUF_SHIFT to a more sensible place
Several people have observed that perhaps LOG_BUF_SHIFT should be in a more
obvious place than under DEBUG_KERNEL. Under some circumstances (such as the
PARISC architecture), DEBUG_KERNEL can increase kernel size, which is an
undesirable trade off for something as trivial as increasing the kernel log
buffer size.

Instead, move LOG_BUF_SHIFT into "General Setup", so that people are more
likely to be able to change it such a circumstance that the default buffer
size is insufficient.

Signed-off-by: Alistair John Strachan <s0348365@sms.ed.ac.uk>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 11:15:14 -07:00
Bryan Wu
1394f03221 blackfin architecture
This adds support for the Analog Devices Blackfin processor architecture, and
currently supports the BF533, BF532, BF531, BF537, BF536, BF534, and BF561
(Dual Core) devices, with a variety of development platforms including those
avaliable from Analog Devices (BF533-EZKit, BF533-STAMP, BF537-STAMP,
BF561-EZKIT), and Bluetechnix!  Tinyboards.

The Blackfin architecture was jointly developed by Intel and Analog Devices
Inc.  (ADI) as the Micro Signal Architecture (MSA) core and introduced it in
December of 2000.  Since then ADI has put this core into its Blackfin
processor family of devices.  The Blackfin core has the advantages of a clean,
orthogonal,RISC-like microprocessor instruction set.  It combines a dual-MAC
(Multiply/Accumulate), state-of-the-art signal processing engine and
single-instruction, multiple-data (SIMD) multimedia capabilities into a single
instruction-set architecture.

The Blackfin architecture, including the instruction set, is described by the
ADSP-BF53x/BF56x Blackfin Processor Programming Reference
http://blackfin.uclinux.org/gf/download/frsrelease/29/2549/Blackfin_PRM.pdf

The Blackfin processor is already supported by major releases of gcc, and
there are binary and source rpms/tarballs for many architectures at:
http://blackfin.uclinux.org/gf/project/toolchain/frs There is complete
documentation, including "getting started" guides available at:
http://docs.blackfin.uclinux.org/ which provides links to the sources and
patches you will need in order to set up a cross-compiling environment for
bfin-linux-uclibc

This patch, as well as the other patches (toolchain, distribution,
uClibc) are actively supported by Analog Devices Inc, at:
http://blackfin.uclinux.org/

We have tested this on LTP, and our test plan (including pass/fails) can
be found at:
http://docs.blackfin.uclinux.org/doku.php?id=testing_the_linux_kernel

[m.kozlowski@tuxland.pl: balance parenthesis in blackfin header files]
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
Signed-off-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl>
Signed-off-by: Aubrey Li <aubrey.li@analog.com>
Signed-off-by: Jie Zhang <jie.zhang@analog.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:12:58 -07:00
Christoph Lameter
81819f0fc8 SLUB core
This is a new slab allocator which was motivated by the complexity of the
existing code in mm/slab.c. It attempts to address a variety of concerns
with the existing implementation.

A. Management of object queues

   A particular concern was the complex management of the numerous object
   queues in SLAB. SLUB has no such queues. Instead we dedicate a slab for
   each allocating CPU and use objects from a slab directly instead of
   queueing them up.

B. Storage overhead of object queues

   SLAB Object queues exist per node, per CPU. The alien cache queue even
   has a queue array that contain a queue for each processor on each
   node. For very large systems the number of queues and the number of
   objects that may be caught in those queues grows exponentially. On our
   systems with 1k nodes / processors we have several gigabytes just tied up
   for storing references to objects for those queues  This does not include
   the objects that could be on those queues. One fears that the whole
   memory of the machine could one day be consumed by those queues.

C. SLAB meta data overhead

   SLAB has overhead at the beginning of each slab. This means that data
   cannot be naturally aligned at the beginning of a slab block. SLUB keeps
   all meta data in the corresponding page_struct. Objects can be naturally
   aligned in the slab. F.e. a 128 byte object will be aligned at 128 byte
   boundaries and can fit tightly into a 4k page with no bytes left over.
   SLAB cannot do this.

D. SLAB has a complex cache reaper

   SLUB does not need a cache reaper for UP systems. On SMP systems
   the per CPU slab may be pushed back into partial list but that
   operation is simple and does not require an iteration over a list
   of objects. SLAB expires per CPU, shared and alien object queues
   during cache reaping which may cause strange hold offs.

E. SLAB has complex NUMA policy layer support

   SLUB pushes NUMA policy handling into the page allocator. This means that
   allocation is coarser (SLUB does interleave on a page level) but that
   situation was also present before 2.6.13. SLABs application of
   policies to individual slab objects allocated in SLAB is
   certainly a performance concern due to the frequent references to
   memory policies which may lead a sequence of objects to come from
   one node after another. SLUB will get a slab full of objects
   from one node and then will switch to the next.

F. Reduction of the size of partial slab lists

   SLAB has per node partial lists. This means that over time a large
   number of partial slabs may accumulate on those lists. These can
   only be reused if allocator occur on specific nodes. SLUB has a global
   pool of partial slabs and will consume slabs from that pool to
   decrease fragmentation.

G. Tunables

   SLAB has sophisticated tuning abilities for each slab cache. One can
   manipulate the queue sizes in detail. However, filling the queues still
   requires the uses of the spin lock to check out slabs. SLUB has a global
   parameter (min_slab_order) for tuning. Increasing the minimum slab
   order can decrease the locking overhead. The bigger the slab order the
   less motions of pages between per CPU and partial lists occur and the
   better SLUB will be scaling.

G. Slab merging

   We often have slab caches with similar parameters. SLUB detects those
   on boot up and merges them into the corresponding general caches. This
   leads to more effective memory use. About 50% of all caches can
   be eliminated through slab merging. This will also decrease
   slab fragmentation because partial allocated slabs can be filled
   up again. Slab merging can be switched off by specifying
   slub_nomerge on boot up.

   Note that merging can expose heretofore unknown bugs in the kernel
   because corrupted objects may now be placed differently and corrupt
   differing neighboring objects. Enable sanity checks to find those.

H. Diagnostics

   The current slab diagnostics are difficult to use and require a
   recompilation of the kernel. SLUB contains debugging code that
   is always available (but is kept out of the hot code paths).
   SLUB diagnostics can be enabled via the "slab_debug" option.
   Parameters can be specified to select a single or a group of
   slab caches for diagnostics. This means that the system is running
   with the usual performance and it is much more likely that
   race conditions can be reproduced.

I. Resiliency

   If basic sanity checks are on then SLUB is capable of detecting
   common error conditions and recover as best as possible to allow the
   system to continue.

J. Tracing

   Tracing can be enabled via the slab_debug=T,<slabcache> option
   during boot. SLUB will then protocol all actions on that slabcache
   and dump the object contents on free.

K. On demand DMA cache creation.

   Generally DMA caches are not needed. If a kmalloc is used with
   __GFP_DMA then just create this single slabcache that is needed.
   For systems that have no ZONE_DMA requirement the support is
   completely eliminated.

L. Performance increase

   Some benchmarks have shown speed improvements on kernbench in the
   range of 5-10%. The locking overhead of slub is based on the
   underlying base allocation size. If we can reliably allocate
   larger order pages then it is possible to increase slub
   performance much further. The anti-fragmentation patches may
   enable further performance increases.

Tested on:
i386 UP + SMP, x86_64 UP + SMP + NUMA emulation, IA64 NUMA + Simulator

SLUB Boot options

slub_nomerge		Disable merging of slabs
slub_min_order=x	Require a minimum order for slab caches. This
			increases the managed chunk size and therefore
			reduces meta data and locking overhead.
slub_min_objects=x	Mininum objects per slab. Default is 8.
slub_max_order=x	Avoid generating slabs larger than order specified.
slub_debug		Enable all diagnostics for all caches
slub_debug=<options>	Enable selective options for all caches
slub_debug=<o>,<cache>	Enable selective options for a certain set of
			caches

Available Debug options
F		Double Free checking, sanity and resiliency
R		Red zoning
P		Object / padding poisoning
U		Track last free / alloc
T		Trace all allocs / frees (only use for individual slabs).

To use SLUB: Apply this patch and then select SLUB as the default slab
allocator.

[hugh@veritas.com: fix an oops-causing locking error]
[akpm@linux-foundation.org: various stupid cleanups and small fixes]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:12:53 -07:00
Robert P. J. Day
6e5a5420b7 kbuild: clarify the creation of the LOCALVERSION_AUTO string.
Clarify the creation of the LOCALVERSION_AUTO string during kernel
configuration, and fix a couple typoes while we're there.

Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2007-05-02 20:58:11 +02:00
Dimitri Gorokhovik
f991633de6 [PATCH] initramfs should not depend on CONFIG_BLOCK
initramfs ended up depending on BLOCK:

  INITRAMFS_SOURCE <-- BLK_DEV_INITRD <-- BLOCK

This inhibits use of customized-initramfs-over-ramfs without block layer
(ramfs would still be enabled), useful in embedded applications.

Move BLK_DEV_INITRD out of 'drivers/block/Kconfig' and into 'init/Kconfig',
make it unconditional.

Signed-off-by: Dimitri Gorokhovik <dimitri.gorokhovik@free.fr>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-06 09:30:25 -08:00
Eric W. Biederman
a5494dcd8b [PATCH] sysctl: move SYSV IPC sysctls to their own file
This is just a simple cleanup to keep kernel/sysctl.c from getting to crowded
with special cases, and by keeping all of the ipc logic to together it makes
the code a little more readable.

[gcoady.lk@gmail.com: build fix]
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Serge E. Hallyn <serue@us.ibm.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Kirill Korotaev <dev@sw.ru>
Signed-off-by: Grant Coady <gcoady.lk@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-14 08:09:59 -08:00
Alexey Dobriyan
18f705f49a [PATCH] Move TASK_XACCT, TASK_IO_ACCOUNTING up in menus
Since they depends on TASKSTATS, it would be nice to move them closer to
another options depending on TASKSTATS.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-11 11:18:07 -08:00
Jean-Paul Saman
c33df4eaaf [PATCH] disable init/initramfs.c
The file init/initramfs.c is always compiled and linked in the kernel
vmlinux even when BLK_DEV_RAM and BLK_DEV_INITRD are disabled and the
system isn't using any form of an initramfs or initrd.  In this situation
the code is only used to unpack a (static) default initial rootfilesystem.
The current init/initramfs.c code.  usr/initramfs_data.o compiles to a size
of ~15 kbytes.  Disabling BLK_DEV_RAM and BLK_DEV_INTRD shrinks the kernel
code size with ~60 Kbytes.

This patch avoids compiling in the code and data for initramfs support if
CONFIG_BLK_DEV_INITRD is not defined.  Instead of the initramfs code and
data it uses a small routine in init/noinitramfs.c to setup an initial
static default environment for mounting a rootfilesystem later on in the
kernel initialisation process.  The new code is: 164 bytes of size.

The patch is separated in two parts:
1) doesn't compile initramfs code when CONFIG_BLK_DEV_INITRD is not set
2) changing all plaforms vmlinux.lds.S files to not reserve an area of
PAGE_SIZE when CONFIG_BLK_DEV_INITRD is not set.

[deweerdt@free.fr: warning fix]
Signed-off-by: Jean-Paul Saman <jean-paul.saman@nxp.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Frederik Deweerdt <frederik.deweerdt@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-11 10:51:25 -08:00
Yasunori Goto
561ccd3a97 [PATCH] handle SLOB with sparsemen
This is to disallow to make SLOB with SMP or SPARSEMEM.  This avoids latent
troubles of SLOB with SLAB_DESTROY_BY_RCU.  And fix compile error.

Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-22 08:55:49 -08:00
Paul Jackson
2aea4fb616 [PATCH] CONFIG_VM_EVENT_COUNTER comment decrustify
The VM event counters, enabled by CONFIG_VM_EVENT_COUNTERS, which provides
VM event counters in /proc/vmstat, has become more essential to
non-EMBEDDED kernel configurations than they were in the past.  Comments in
the code and the Kconfig configuration explanation were stale, downplaying
their role excessively.

Refresh those comments to correctly reflect the current role of VM event
counters.

Signed-off-by: Paul Jackson <pj@sgi.com>
Acked-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-22 08:55:46 -08:00
Jesper Juhl
979c6a1e49 Kconfig: fix spelling error in config KALLSYMS help text
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Acked-By: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-12-12 19:25:11 +01:00
Andrew Morton
7c3ab7381e [PATCH] io-accounting: core statistics
The present per-task IO accounting isn't very useful.  It simply counts the
number of bytes passed into read() and write().  So if a process reads 1MB
from an already-cached file, it is accused of having performed 1MB of I/O,
which is wrong.

(David Wright had some comments on the applicability of the present logical IO accounting:

  For billing purposes it is useless but for workload analysis it is very
  useful

  read_bytes/read_calls  average read request size
  write_bytes/write_calls average write request size

  read_bytes/read_blocks ie logical/physical can indicate hit rate or thrashing
  write_bytes/write_blocks  ie logical/physical  guess since pdflush writes can
                                                be missed

  I often look for logical larger than physical to see filesystem cache
  problems.  And the bytes/cpusec can help find applications that are
  dominating the cache and causing slow interactive response from page cache
  contention.

  I want to find the IO intensive applications and make sure they are doing
  efficient IO.  Thus the acctcms(sysV) or csacms command would give the high
  IO commands).

This patchset adds new accounting which tries to be more accurate.  We account
for three things:

reads:

  attempt to count the number of bytes which this process really did cause
  to be fetched from the storage layer.  Done at the submit_bio() level, so it
  is accurate for block-backed filesystems.  I also attempt to wire up NFS and
  CIFS.

writes:

  attempt to count the number of bytes which this process caused to be sent
  to the storage layer.  This is done at page-dirtying time.

  The big inaccuracy here is truncate.  If a process writes 1MB to a file
  and then deletes the file, it will in fact perform no writeout.  But it will
  have been accounted as having caused 1MB of write.

  So...

cancelled_writes:

  account the number of bytes which this process caused to not happen, by
  truncating pagecache.

  We _could_ just subtract this from the process's `write' accounting.  But
  that means that some processes would be reported to have done negative
  amounts of write IO, which is silly.

  So we just report the raw number and punt this decision up to userspace.

Now, we _could_ account for writes at the physical I/O level.  But

- This would require that we track memory-dirtying tasks at the per-page
  level (would require a new pointer in struct page).

- It would mean that IO statistics for a process are usually only available
  long after that process has exitted.  Which means that we probably cannot
  communicate this info via taskstats.

This patch:

Wire up the kernel-private data structures and the accessor functions to
manipulate them.

Cc: Jay Lan <jlan@sgi.com>
Cc: Shailabh Nagar <nagar@watson.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Chris Sturtivant <csturtiv@sgi.com>
Cc: Tony Ernst <tee@sgi.com>
Cc: Guillaume Thouvenin <guillaume.thouvenin@bull.net>
Cc: David Wright <daw@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 09:55:41 -08:00
Kay Sievers
88a22c985e CONFIG_SYSFS_DEPRECATED
Provide a way to support older versions of udev that are shipped in
older distros.  If this option is disabled, it will also turn off the
compatible symlinks in sysfs that older programs might rely on.

When in doubt, or if running a distro older than 2006, say Yes here.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-12-01 14:51:58 -08:00
Eric W. Biederman
13bb7e37e5 [PATCH] sysctl: Undeprecate sys_sysctl
The basic issue is that despite have been deprecated and warned about as a
very bad thing in the man pages since its inception there are a few real
users of sys_sysctl.  It was my assumption that because sysctl had been
deprecated for all of 2.6 there would be no user space users by this point,
so I initially gave sys_sysctl a very short deprecation period.

Now that I know there are a few real users the only sane way to proceed
with deprecation is to push the time limit out to a year or two work and
work with distributions that have big testing pools like fedora core to
find these last remaining users.

Which means that the sys_sysctl interface needs to be maintained in the
meantime.

Since I have provided a technical measure that allows us to add new sysctl
entries without reserving more binary numbers I believe that is enough to
fix the sys_sysctl binary interface maintenance problems, because there is
no longer a need to change the binary interface at all.

Since the sys_sysctl implementation needs to stay around for a while and
the worst of the maintenance issues that caused us to occasionally break
the ABI have been addressed I don't see any advantage in continuing with
the removal of sys_sysctl.

So instead of merely increasing the deprecation period this patch removes
the deprecation of sys_sysctl and modifies the kernel to compile the code
in by default.

With committing to maintain sys_sysctl we get all of the advantages of a
fast interface for anything that needs it.  Currently sys_sysctl is about
5x faster than /proc/sys, for the same string data.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-11-08 18:29:24 -08:00
Paolo 'Blaisorblade' Giarrusso
b2670eacfb [PATCH] uml: use DEFCONFIG_LIST to avoid reading host's config
This should make sure that, for UML, host's configuration files are not
considered, which avoids various pains to the user.  Our dependency are such
that the obtained Kconfig will be valid and will lead to successful
compilation - however they cannot prevent an user from disabling any boot
device, and if an option is not set in the read .config (say
/boot/config-XXX), with make menuconfig ARCH=um, it is not set.  This always
disables UBD and all console I/O channels, which leads to non-working UML
kernels, so this bothers users - especially now, since it will happen on
almost every machine (/boot/config-`uname -r` exists almost on every machine).
 It can be workarounded with make defconfig ARCH=um, but it is non-obvious and
can be avoided, so please _do_ merge this patch.

Given the existence of options, it could be interesting to implement
(additionally) "option required" - with it, Kconfig will refuse reading a
.config file (from wherever it comes) if the given option is not set.  With
this, one could mark with it the option characteristic of the given
architecture (it was an old proposal of Roman Zippel, when I pointed out our
problem):

config UML
	option required
	default y

However this should be further discussed:
*) for x86, it must support constructs like:

==arch/i386/Kconfig==
config 64BIT
	option required
	default n
where Kconfig must require that CONFIG_64BIT is disabled or not present in the
read .config.

*) do we want to do such checks only for the starting defconfig or also for
   .config? Which leads to:
*) I may want to port a x86_64 .config to x86 and viceversa, or even among more
   different archs. Should that be allowed, and in which measure (the user may
   force skipping the check for a .config or it is only given a warning by
   default)?

Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: <kbuild-devel@lists.sourceforge.net>
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-20 10:26:36 -07:00
Kirill Korotaev
25b21cb2f6 [PATCH] IPC namespace core
This patch set allows to unshare IPCs and have a private set of IPC objects
(sem, shm, msg) inside namespace.  Basically, it is another building block of
containers functionality.

This patch implements core IPC namespace changes:
- ipc_namespace structure
- new config option CONFIG_IPC_NS
- adds CLONE_NEWIPC flag
- unshare support

[clg@fr.ibm.com: small fix for unshare of ipc namespace]
[akpm@osdl.org: build fix]
Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Signed-off-by: Kirill Korotaev <dev@openvz.org>
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02 07:57:22 -07:00
Serge E. Hallyn
4865ecf131 [PATCH] namespaces: utsname: implement utsname namespaces
This patch defines the uts namespace and some manipulators.
Adds the uts namespace to task_struct, and initializes a
system-wide init namespace.

It leaves a #define for system_utsname so sysctl will compile.
This define will be removed in a separate patch.

[akpm@osdl.org: build fix, cleanup]
Signed-off-by: Serge Hallyn <serue@us.ibm.com>
Cc: Kirill Korotaev <dev@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Andrey Savochkin <saw@sw.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02 07:57:21 -07:00
Jay Lan
9acc185351 [PATCH] csa: Extended system accounting over taskstats
Add extended system accounting handling over taskstats interface.  A
CONFIG_TASK_XACCT flag is created to enable the extended accounting code.

Signed-off-by: Jay Lan <jlan@sgi.com>
Cc: Shailabh Nagar <nagar@watson.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Jes Sorensen <jes@sgi.com>
Cc: Chris Sturtivant <csturtiv@sgi.com>
Cc: Tony Ernst <tee@sgi.com>
Cc: Guillaume Thouvenin <guillaume.thouvenin@bull.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 00:39:29 -07:00
Randy Dunlap
0847062ad5 [PATCH] fix EMBEDDED + SYSCTL menu
SYSCTL should still depend on EMBEDDED.  This unbreaks the EMBEDDED menu
(from the recent SYSCTL_SYCALL menu option patch).

Fix typos in new SYSCTL_SYSCALL menu.

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 00:39:25 -07:00
Ross Biro
f2443ab6c4 [PATCH] allow /proc/config.gz to be built as a module
The driver for /proc/config.gz consumes rather a lot of memory and it is in
fact possible to build it as a module.

In some ways this is a bit risky, because the .config which is used for
compiling kernel/configs.c isn't necessarily the same as the .config which was
used to build vmlinux.

But OTOH the potential memory savings are decent, and it'd be fairly dumb to
build your configs.o with a different .config.

Signed-off-by: Andrew Morton <akpm@google.com>
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 00:39:20 -07:00
David Howells
9361401eb7 [PATCH] BLOCK: Make it possible to disable the block layer [try #6]
Make it possible to disable the block layer.  Not all embedded devices require
it, some can make do with just JFFS2, NFS, ramfs, etc - none of which require
the block layer to be present.

This patch does the following:

 (*) Introduces CONFIG_BLOCK to disable the block layer, buffering and blockdev
     support.

 (*) Adds dependencies on CONFIG_BLOCK to any configuration item that controls
     an item that uses the block layer.  This includes:

     (*) Block I/O tracing.

     (*) Disk partition code.

     (*) All filesystems that are block based, eg: Ext3, ReiserFS, ISOFS.

     (*) The SCSI layer.  As far as I can tell, even SCSI chardevs use the
     	 block layer to do scheduling.  Some drivers that use SCSI facilities -
     	 such as USB storage - end up disabled indirectly from this.

     (*) Various block-based device drivers, such as IDE and the old CDROM
     	 drivers.

     (*) MTD blockdev handling and FTL.

     (*) JFFS - which uses set_bdev_super(), something it could avoid doing by
     	 taking a leaf out of JFFS2's book.

 (*) Makes most of the contents of linux/blkdev.h, linux/buffer_head.h and
     linux/elevator.h contingent on CONFIG_BLOCK being set.  sector_div() is,
     however, still used in places, and so is still available.

 (*) Also made contingent are the contents of linux/mpage.h, linux/genhd.h and
     parts of linux/fs.h.

 (*) Makes a number of files in fs/ contingent on CONFIG_BLOCK.

 (*) Makes mm/bounce.c (bounce buffering) contingent on CONFIG_BLOCK.

 (*) set_page_dirty() doesn't call __set_page_dirty_buffers() if CONFIG_BLOCK
     is not enabled.

 (*) fs/no-block.c is created to hold out-of-line stubs and things that are
     required when CONFIG_BLOCK is not set:

     (*) Default blockdev file operations (to give error ENODEV on opening).

 (*) Makes some /proc changes:

     (*) /proc/devices does not list any blockdevs.

     (*) /proc/diskstats and /proc/partitions are contingent on CONFIG_BLOCK.

 (*) Makes some compat ioctl handling contingent on CONFIG_BLOCK.

 (*) If CONFIG_BLOCK is not defined, makes sys_quotactl() return -ENODEV if
     given command other than Q_SYNC or if a special device is specified.

 (*) In init/do_mounts.c, no reference is made to the blockdev routines if
     CONFIG_BLOCK is not defined.  This does not prohibit NFS roots or JFFS2.

 (*) The bdflush, ioprio_set and ioprio_get syscalls can now be absent (return
     error ENOSYS by way of cond_syscall if so).

 (*) The seclvl_bd_claim() and seclvl_bd_release() security calls do nothing if
     CONFIG_BLOCK is not set, since they can't then happen.

Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2006-09-30 20:52:31 +02:00