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>
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>
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>
* 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
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
