Commit graph

1375 commits

Author SHA1 Message Date
Stephen Rothwell
193faea928 Move three functions that are only needed for CONFIG_MEMORY_HOTPLUG
into the appropriate #ifdef.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-06-08 17:23:33 -07:00
Christoph Lameter
272c1d21d6 SLUB: return ZERO_SIZE_PTR for kmalloc(0)
Instead of returning the smallest available object return ZERO_SIZE_PTR.

A ZERO_SIZE_PTR can be legitimately used as an object pointer as long as it
is not deferenced.  The dereference of ZERO_SIZE_PTR causes a distinctive
fault.  kfree can handle a ZERO_SIZE_PTR in the same way as NULL.

This enables functions to use zero sized object. e.g. n = number of objects.

	objects = kmalloc(n * sizeof(object));

	for (i = 0; i < n; i++)
		objects[i].x = y;

	kfree(objects);

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-06-08 17:23:33 -07:00
Christoph Lameter
3cdc0ed0ce slab: fix alien cache handling
cache_free_alien must be called regardless if we use alien caches or not.
cache_free_alien() will do the right thing if there are no alien caches
available.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Acked-by: Pekka J Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-06-08 17:23:32 -07:00
Hugh Dickins
a210906c1b mount -t tmpfs -o mpol=: check nodes online
Randy Dunlap reports that a tmpfs, mounted with NUMA mpol= specifying an
offline node, crashes as soon as data is allocated upon it.  Now restrict it
to online nodes, where before it restricted to MAX_NUMNODES.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: Robin Holt <holt@sgi.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Andi Kleen <ak@suse.de>
Tested-and-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>
2007-06-08 17:23:32 -07:00
Christoph Lameter
27390bc335 SLUB: fix locking for hotplug callbacks
Hotplug callbacks are performed with interrupts enabled.  Slub requires
interrupts to be disabled for flushing caches.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Michal Piotrowski <michal.k.k.piotrowski@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-06-01 08:18:30 -07:00
Yasunori Goto
13466c8419 memory hotplug: fix unnecessary calling of init_currenty_empty_zone()
zone->present_pages is updated in online_pages().  But, __add_zone() can be
called twice or more before calling online_pages().  So,
init_currenty_empty_zone() can be called unnecessary times.  It is cause of
memory leak of zone's wait_table.

Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-06-01 08:18:29 -07:00
Zou Nan hai
2e1c49db4c x86_64: allocate sparsemem memmap above 4G
On systems with huge amount of physical memory, VFS cache and memory memmap
may eat all available system memory under 4G, then the system may fail to
allocate swiotlb bounce buffer.

There was a fix for this issue in arch/x86_64/mm/numa.c, but that fix dose
not cover sparsemem model.

This patch add fix to sparsemem model by first try to allocate memmap above
4G.

Signed-off-by: Zou Nan hai <nanhai.zou@intel.com>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Andi Kleen <ak@suse.de>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-06-01 08:18:27 -07:00
Roman Zippel
12d810c1b8 m68k: discontinuous memory support
Fix support for discontinuous memory

Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-31 07:58:14 -07:00
Christoph Lameter
8ffa68755a SLUB: Fix NUMA / SYSFS bootstrap issue
We need this patch in ASAP.  Patch fixes the mysterious hang that remained
on some particular configurations with lockdep on after the first fix that
moved the #idef CONFIG_SLUB_DEBUG to the right location.  See
http://marc.info/?t=117963072300001&r=1&w=2

The kmem_cache_node cache is very special because it is needed for NUMA
bootstrap.  Under certain conditions (like for example if lockdep is
enabled and significantly increases the size of spinlock_t) the structure
may become exactly the size as one of the larger caches in the kmalloc
array.

That early during bootstrap we cannot perform merging properly.  The unique
id for the kmem_cache_node cache will match one of the kmalloc array.
Sysfs will complain about a duplicate directory entry.  All of this occurs
while the console is not yet fully operational.  Thus boot may appear to be
silently failing.

The kmem_cache_node cache is very special.  During early boostrap the main
allocation function is not operational yet and so we have to run our own
small special alloc function during early boot.  It is also special in that
it is never freed.

We really do not want any merging on that cache.  Set the refcount -1 and
forbid merging of slabs that have a negative refcount.

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>
2007-05-31 07:58:14 -07:00
Christoph Lameter
33e9e24101 SLUB Debug: fix check for super sized slabs (>512k 64bit, >256k 32bit)
The check for super sized slabs where we can no longer move the free
pointer behind the object for debugging purposes etc is accessing a
field that is not setup yet.  We must use objsize here since the size of
the slab has not been determined yet.

The effect of this is that a global slab shrink via "slabinfo -s" will
show errors about offsets being wrong if booted with slub_debug.
Potentially there are other troubles with huge slabs under slub_debug
because the calculated free pointer offset is truncated.

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>
2007-05-23 20:14:13 -07:00
Miklos Szeredi
418508c132 fix unused setup_nr_node_ids
mm/page_alloc.c:931: warning: 'setup_nr_node_ids' defined but not used

This is now the only (!) compiler warning I get in my UML build :)

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-23 20:14:13 -07:00
Christoph Lameter
c12b3c6251 SLUB Debug: Fix object size calculation
The object size calculation is wrong if !CONFIG_SLUB_DEBUG because the
#ifdef CONFIG_SLUB_DEBUG is now switching off the size adjustments for
DESTROY_BY_RCU and ctor.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Acked-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-23 20:14:11 -07:00
Linus Torvalds
080e89270a Merge git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild-fix
* git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild-fix:
  mm/slab: fix section mismatch warning
  mm: fix section mismatch warnings
  init/main: use __init_refok to fix section mismatch
  kbuild: introduce __init_refok/__initdata_refok to supress section mismatch warnings
  all-archs: consolidate .data section definition in asm-generic
  all-archs: consolidate .text section definition in asm-generic
  kbuild: add "Section mismatch" warning whitelist for powerpc
  kbuild: make better section mismatch reports on i386, arm and mips
  kbuild: make modpost section warnings clearer
  kconfig: search harder for curses library in check-lxdialog.sh
  kbuild: include limits.h in sumversion.c for PATH_MAX
  powerpc: Fix the MODALIAS generation in modpost for of devices
2007-05-21 12:03:04 -07:00
Alexey Dobriyan
e8edc6e03a Detach sched.h from mm.h
First thing mm.h does is including sched.h solely for can_do_mlock() inline
function which has "current" dereference inside. By dealing with can_do_mlock()
mm.h can be detached from sched.h which is good. See below, why.

This patch
a) removes unconditional inclusion of sched.h from mm.h
b) makes can_do_mlock() normal function in mm/mlock.c
c) exports can_do_mlock() to not break compilation
d) adds sched.h inclusions back to files that were getting it indirectly.
e) adds less bloated headers to some files (asm/signal.h, jiffies.h) that were
   getting them indirectly

Net result is:
a) mm.h users would get less code to open, read, preprocess, parse, ... if
   they don't need sched.h
b) sched.h stops being dependency for significant number of files:
   on x86_64 allmodconfig touching sched.h results in recompile of 4083 files,
   after patch it's only 3744 (-8.3%).

Cross-compile tested on

	all arm defconfigs, all mips defconfigs, all powerpc defconfigs,
	alpha alpha-up
	arm
	i386 i386-up i386-defconfig i386-allnoconfig
	ia64 ia64-up
	m68k
	mips
	parisc parisc-up
	powerpc powerpc-up
	s390 s390-up
	sparc sparc-up
	sparc64 sparc64-up
	um-x86_64
	x86_64 x86_64-up x86_64-defconfig x86_64-allnoconfig

as well as my two usual configs.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-21 09:18:19 -07:00
Sam Ravnborg
38bdc32af4 mm/slab: fix section mismatch warning
Use the new __init_refok marker to avoid the
section mismatch warning from slab.c

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2007-05-19 09:11:58 +02:00
Sam Ravnborg
577a32f620 mm: fix section mismatch warnings
modpost had two cases hardcoded for mm/
Shift over to __init_refok and kill the
hardcoded function names in modpost.

This has the drawback that the functions
will always be kept no matter configuration.
With previous code the function were placed in
init section if configuration allowed it.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2007-05-19 09:11:58 +02:00
Nick Piggin
c97a9e10ea mm: more rmap checking
Re-introduce rmap verification patches that Hugh removed when he removed
PG_map_lock. PG_map_lock actually isn't needed to synchronise access to
anonymous pages, because PG_locked and PTL together already do.

These checks were important in discovering and fixing a rare rmap corruption
in SLES9.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-17 05:23:06 -07:00
Benjamin Herrenschmidt
d55e2ca873 Make __vunmap static
__vunmap doesn't seem to be used outside of mm/vmalloc.c, and has
no prototype in any header so let's make it static

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-17 05:23:04 -07:00
Christoph Lameter
0aa817f078 Slab allocators: define common size limitations
Currently we have a maze of configuration variables that determine the
maximum slab size.  Worst of all it seems to vary between SLAB and SLUB.

So define a common maximum size for kmalloc.  For conveniences sake we use
the maximum size ever supported which is 32 MB.  We limit the maximum size
to a lower limit if MAX_ORDER does not allow such large allocations.

For many architectures this patch will have the effect of adding large
kmalloc sizes.  x86_64 adds 5 new kmalloc sizes.  So a small amount of
memory will be needed for these caches (contemporary SLAB has dynamically
sizeable node and cpu structure so the waste is less than in the past)

Most architectures will then be able to allocate object with sizes up to
MAX_ORDER.  We have had repeated breakage (in fact whenever we doubled the
number of supported processors) on IA64 because one or the other struct
grew beyond what the slab allocators supported.  This will avoid future
issues and f.e.  avoid fixes for 2k and 4k cpu support.

CONFIG_LARGE_ALLOCS is no longer necessary so drop it.

It fixes sparc64 with SLAB.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-17 05:23:04 -07:00
Christoph Lameter
3ec0974210 SLUB: Simplify debug code
Consolidate functionality into the #ifdef section.

Extract tracing into one subroutine.

Move object debug processing into the #ifdef section so that the
code in __slab_alloc and __slab_free becomes minimal.

Reduce number of functions we need to provide stubs for in the !SLUB_DEBUG case.

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 05:23:04 -07:00
Christoph Lameter
a35afb830f Remove SLAB_CTOR_CONSTRUCTOR
SLAB_CTOR_CONSTRUCTOR is always specified. No point in checking it.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Steven French <sfrench@us.ibm.com>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Dave Kleikamp <shaggy@austin.ibm.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Anton Altaparmakov <aia21@cantab.net>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jan Kara <jack@ucw.cz>
Cc: David Chinner <dgc@sgi.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-17 05:23:04 -07:00
Christoph Lameter
5577bd8a85 SLUB: Do our own flags based on PG_active and PG_error
The atomicity when handling flags in SLUB is not necessary since both flags
used by SLUB are not updated in a racy way.  Flag updates are either done
during slab creation or destruction or under slab_lock.  Some of these flags
do not have the non atomic variants that we need.  So define our own.

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
Christoph Lameter
0b44f7a5b5 slab: warn on zero-length allocations
slub warns on this, and we're working on making kmalloc(0) return NULL.
Let's make slab warn as well so our testers detect such callers more
rapidly.

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
Christoph Lameter
4b6f075045 SLUB: Define functions for cpu slab handling instead of using PageActive
Use inline functions to access the per cpu bit.  Intoduce the notion of
"freezing" a slab to make things more understandable.

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
Christoph Lameter
c59def9f22 Slab allocators: Drop support for destructors
There is no user of destructors left.  There is no reason why we should keep
checking for destructors calls in the slab allocators.

The RFC for this patch was discussed at
http://marc.info/?l=linux-kernel&m=117882364330705&w=2

Destructors were mainly used for list management which required them to take a
spinlock.  Taking a spinlock in a destructor is a bit risky since the slab
allocators may run the destructors anytime they decide a slab is no longer
needed.

Patch drops destructor support.  Any attempt to use a destructor will BUG().

Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Paul Mundt <lethal@linux-sh.org>
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
Christoph Lameter
43c0f3d25c Fix: find_or_create_page skips cpuset memory spreading.
We call alloc_page where we should be calling __page_cache_alloc.

__page_cache_alloc performs cpuset memory spreading.  alloc_page does not.
There is no reason that pages allocated via find_or_create should be
exempt.

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>
2007-05-16 21:19:15 -07:00
Hugh Dickins
1800782016 slub: don't confuse ctor and dtor
kmem_cache_create() was swapping ctor and dtor in calling find_mergeable():
though it caused no bug, and probably never would, even if destructors are
retained; but fix it so as not to generate anxiety ;)

Signed-off-by: Hugh Dickins <hugh@veritas.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>
2007-05-16 21:19:15 -07:00
Paul Mundt
6c645ac725 sh64: generic quicklist support.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2007-05-14 09:55:35 +09:00
Miklos Szeredi
0ea9718016 consolidate generic_writepages and mpage_writepages
Clean up massive code duplication between mpage_writepages() and
generic_writepages().

The new generic function, write_cache_pages() takes a function pointer
argument, which will be called for each page to be written.

Maybe cifs_writepages() too can use this infrastructure, but I'm not
touching that with a ten-foot pole.

The upcoming page writeback support in fuse will also want this.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-11 08:29:35 -07:00
Christoph Lameter
39bf6270f5 VM statistics: Make timer deferrable
VM statistics updates do not matter if the kernel is in idle powersaving
mode.  So allow the timer to be deferred.

It would be better though if we could switch the timer between deferrable
and nondeferrable based on differentials present.  The timer would start
out nondeferrable and if we find that there were no updates in the last
statistics interval then we would switch the timer to deferrable.  If the
timer later finds again that there are differentials then go to
nondeferrable again.

And yet another way would be to run the timer shortly before going to idle?

The solution here means that the VM counters may be slightly off during
idle since differentials may be still pending while the timer is deferred.

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>
2007-05-11 08:29:32 -07:00
Mika Kukkonen
7faaa5f0bf Bug in mm/thrash.c function grab_swap_token()
Following bug was uncovered by compiling with '-W' flag:

  CC      mm/thrash.o
mm/thrash.c: In function ‘grab_swap_token’:
mm/thrash.c:52: warning: comparison of unsigned expression < 0 is always false

Variable token_priority is unsigned, so decrementing first and then
checking the result does not work; fixed by reversing the test, patch
attached (compile tested only).

I am not sure if likely() makes much sense in this new situation, but
I'll let somebody else to make a decision on that.

Signed-off-by: Mika Kukkonen <mikukkon@iki.fi>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-11 08:29:32 -07:00
Christoph Lameter
bcf889f965 SLUB: remove nr_cpu_ids hack
This was in SLUB in order to head off trouble while the nr_cpu_ids
functionality was not merged.  Its merged now so no need to still have this.

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
Stephen Rothwell
6f076f5dd9 early_pfn_to_nid needs to be __meminit
Since it is referenced by memmap_init_zone (which is __meminit) via the
early_pfn_in_nid macro when CONFIG_NODES_SPAN_OTHER_NODES is set (which
basically means PowerPC 64).

This removes a section mismatch warning in those circumstances.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-10 09:26:52 -07:00
Christoph Lameter
894b8788d7 slub: support concurrent local and remote frees and allocs on a slab
Avoid atomic overhead in slab_alloc and slab_free

SLUB needs to use the slab_lock for the per cpu slabs to synchronize with
potential kfree operations.  This patch avoids that need by moving all free
objects onto a lockless_freelist.  The regular freelist continues to exist
and will be used to free objects.  So while we consume the
lockless_freelist the regular freelist may build up objects.

If we are out of objects on the lockless_freelist then we may check the
regular freelist.  If it has objects then we move those over to the
lockless_freelist and do this again.  There is a significant savings in
terms of atomic operations that have to be performed.

We can even free directly to the lockless_freelist if we know that we are
running on the same processor.  So this speeds up short lived objects.
They may be allocated and freed without taking the slab_lock.  This is
particular good for netperf.

In order to maximize the effect of the new faster hotpath we extract the
hottest performance pieces into inlined functions.  These are then inlined
into kmem_cache_alloc and kmem_cache_free.  So hotpath allocation and
freeing no longer requires a subroutine call within SLUB.

[I am not sure that it is worth doing this because it changes the easy to
read structure of slub just to reduce atomic ops.  However, there is
someone out there with a benchmark on 4 way and 8 way processor systems
that seems to show a 5% regression vs.  Slab.  Seems that the regression is
due to increased atomic operations use vs.  SLAB in SLUB).  I wonder if
this is applicable or discernable at all in a real workload?]

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 09:26:52 -07:00
Linus Torvalds
d84c4124c4 Merge master.kernel.org:/pub/scm/linux/kernel/git/lethal/sh-2.6
* master.kernel.org:/pub/scm/linux/kernel/git/lethal/sh-2.6:
  sh: Fix stacktrace simplification fallout.
  sh: SH7760 DMABRG support.
  sh: clockevent/clocksource/hrtimers/nohz TMU support.
  sh: Truncate MAX_ACTIVE_REGIONS for the common case.
  rtc: rtc-sh: Fix rtc_dev pointer for rtc_update_irq().
  sh: Convert to common die chain.
  sh: Wire up utimensat syscall.
  sh: landisk mv_nr_irqs definition.
  sh: Fixup ndelay() xloops calculation for alternate HZ.
  sh: Add 32-bit opcode feature CPU flag.
  sh: Fix PC adjustments for varying opcode length.
  sh: Support for SH-2A 32-bit opcodes.
  sh: Kill off redundant __div64_32 symbol export.
  sh: Share exception vector table for SH-3/4.
  sh: Always define TRAPA_BUG_OPCODE.
  sh: __GFP_REPEAT for pte allocations, too.
  rtc: rtc-sh: Fix up dev_dbg() warnings.
  sh: generic quicklist support.
2007-05-09 13:08:20 -07:00
David Howells
c855ff3718 Fix a bad error case handling in read_cache_page_async()
Commit 6fe6900e1e introduced a nasty bug
in read_cache_page_async().

It added a "mark_page_accessed(page)" at the final return path in
read_cache_page_async().  But in error cases, 'page' holds the error
code, and you can't mark it accessed.

[ and Glauber de Oliveira Costa points out that we can use a return
  instead of adding more goto's ]

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 13:04:03 -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
4037d45220 Move remote node draining out of slab allocators
Currently the slab allocators contain callbacks into the page allocator to
perform the draining of pagesets on remote nodes.  This requires SLUB to have
a whole subsystem in order to be compatible with SLAB.  Moving node draining
out of the slab allocators avoids a section of code in SLUB.

Move the node draining so that is is done when the vm statistics are updated.
At that point we are already touching all the cachelines with the pagesets of
a processor.

Add a expire counter there.  If we have to update per zone or global vm
statistics then assume that the pageset will require subsequent draining.

The expire counter will be decremented on each vm stats update pass until it
reaches zero.  Then we will drain one batch from the pageset.  The draining
will cause vm counter updates which will then cause another expiration until
the pcp is empty.  So we will drain a batch every 3 seconds.

Note that remote node draining is a somewhat esoteric feature that is required
on large NUMA systems because otherwise significant portions of system memory
can become trapped in pcp queues.  The number of pcp is determined by the
number of processors and nodes in a system.  A system with 4 processors and 2
nodes has 8 pcps which is okay.  But a system with 1024 processors and 512
nodes has 512k pcps with a high potential for large amount of memory being
caught in them.

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 12:30:56 -07:00
Christoph Lameter
77461ab332 Make vm statistics update interval configurable
Make it configurable.  Code in mm makes the vm statistics intervals
independent from the cache reaper use that opportunity to make it
configurable.

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 12:30:56 -07:00
Christoph Lameter
d1187ed210 vmstat: use our own timer events
vmstat is currently using the cache reaper to periodically bring the
statistics up to date.  The cache reaper does only exists in SLUB as a way to
provide compatibility with SLAB.  This patch removes the vmstat calls from the
slab allocators and provides its own handling.

The advantage is also that we can use a different frequency for the updates.
Refreshing vm stats is a pretty fast job so we can run this every second and
stagger this by only one tick.  This will lead to some overlap in large
systems.  F.e a system running at 250 HZ with 1024 processors will have 4 vm
updates occurring at once.

However, the vm stats update only accesses per node information.  It is only
necessary to stagger the vm statistics updates per processor in each node.  Vm
counter updates occurring on distant nodes will not cause cacheline
contention.

We could implement an alternate approach that runs the first processor on each
node at the second and then each of the other processor on a node on a
subsequent tick.  That may be useful to keep a large amount of the second free
of timer activity.  Maybe the timer folks will have some feedback on this one?

[jirislaby@gmail.com: add missing break]
Cc: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Jiri Slaby <jirislaby@gmail.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>
2007-05-09 12:30:56 -07:00
Rafael J. Wysocki
8bb7844286 Add suspend-related notifications for CPU hotplug
Since nonboot CPUs are now disabled after tasks and devices have been
frozen and the CPU hotplug infrastructure is used for this purpose, we need
special CPU hotplug notifications that will help the CPU-hotplug-aware
subsystems distinguish normal CPU hotplug events from CPU hotplug events
related to a system-wide suspend or resume operation in progress.  This
patch introduces such notifications and causes them to be used during
suspend and resume transitions.  It also changes all of the
CPU-hotplug-aware subsystems to take these notifications into consideration
(for now they are handled in the same way as the corresponding "normal"
ones).

[oleg@tv-sign.ru: cleanups]
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:56 -07:00
Nate Diller
01f2705daf fs: convert core functions to zero_user_page
It's very common for file systems to need to zero part or all of a page,
the simplist way is just to use kmap_atomic() and memset().  There's
actually a library function in include/linux/highmem.h that does exactly
that, but it's confusingly named memclear_highpage_flush(), which is
descriptive of *how* it does the work rather than what the *purpose* is.
So this patchset renames the function to zero_user_page(), and calls it
from the various places that currently open code it.

This first patch introduces the new function call, and converts all the
core kernel callsites, both the open-coded ones and the old
memclear_highpage_flush() ones.  Following this patch is a series of
conversions for each file system individually, per AKPM, and finally a
patch deprecating the old call.  The diffstat below shows the entire
patchset.

[akpm@linux-foundation.org: fix a few things]
Signed-off-by: Nate Diller <nate.diller@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:55 -07:00
Christoph Lameter
5830c59021 slab: shut down cache_reaper when cpu goes down
Shutdown the cache_reaper if the cpu is brought down and set the
cache_reap.func to NULL.  Otherwise hotplug shuts down the reaper for good.

Signed-off-by: Christoph Lameter <clameter@sgi.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>
2007-05-09 12:30:53 -07:00
Heiko Carstens
38c3bd96a0 slab: use CPU_LOCK_[ACQUIRE|RELEASE]
Looks like this was forgotten when CPU_LOCK_[ACQUIRE|RELEASE] was
introduced.

Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com>
Cc: Gautham Shenoy <ego@in.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.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>
2007-05-09 12:30:51 -07:00
David Howells
ef71c15c46 AFS: export a couple of core functions for AFS write support
Export a couple of core functions for AFS write support to use:

	find_get_pages_contig()
	find_get_pages_tag()

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:50 -07:00
Ken Chen
8a63011275 pretend cpuset has some form of hugetlb page reservation
When cpuset is configured, it breaks the strict hugetlb page reservation as
the accounting is done on a global variable.  Such reservation is
completely rubbish in the presence of cpuset because the reservation is not
checked against page availability for the current cpuset.  Application can
still potentially OOM'ed by kernel with lack of free htlb page in cpuset
that the task is in.  Attempt to enforce strict accounting with cpuset is
almost impossible (or too ugly) because cpuset is too fluid that task or
memory node can be dynamically moved between cpusets.

The change of semantics for shared hugetlb mapping with cpuset is
undesirable.  However, in order to preserve some of the semantics, we fall
back to check against current free page availability as a best attempt and
hopefully to minimize the impact of changing semantics that cpuset has on
hugetlb.

Signed-off-by: Ken Chen <kenchen@google.com>
Cc: Paul Jackson <pj@sgi.com>
Cc: Christoph Lameter <clameter@engr.sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:49 -07:00
Ken Chen
ace4bd29c2 fix leaky resv_huge_pages when cpuset is in use
The internal hugetlb resv_huge_pages variable can permanently leak nonzero
value in the error path of hugetlb page fault handler when hugetlb page is
used in combination of cpuset.  The leaked count can permanently trap N
number of hugetlb pages in unusable "reserved" state.

Steps to reproduce the bug:

  (1) create two cpuset, user1 and user2
  (2) reserve 50 htlb pages in cpuset user1
  (3) attempt to shmget/shmat 50 htlb page inside cpuset user2
  (4) kernel oom the user process in step 3
  (5) ipcrm the shm segment

At this point resv_huge_pages will have a count of 49, even though
there are no active hugetlbfs file nor hugetlb shared memory segment
in the system.  The leak is permanent and there is no recovery method
other than system reboot. The leaked count will hold up all future use
of that many htlb pages in all cpusets.

The culprit is that the error path of alloc_huge_page() did not
properly undo the change it made to resv_huge_page, causing
inconsistent state.

Signed-off-by: Ken Chen <kenchen@google.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Adam Litke <agl@us.ibm.com>
Cc: Martin Bligh <mbligh@google.com>
Acked-by: David Gibson <dwg@au1.ibm.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:48 -07:00
Pekka J Enberg
7ae439ce0c krealloc: fix kerneldoc comments
No "blank" (or "*") line is allowed between the function name and lines for
it parameter(s).

Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:46 -07:00
Christoph Lameter
5e6d444ea1 SLUB: rework slab order determination
In some cases SLUB is creating uselessly slabs that are larger than
slub_max_order. Also the layout of some of the slabs was not satisfactory.

Go to an iterarive approach.

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 12:30:46 -07:00