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  1. 26 Nov, 2008 2 commits
  3. 23 Oct, 2008 2 commits
  5. 29 Jul, 2008 1 commit
  7. 26 Jul, 2008 1 commit
  9. 15 Jul, 2008 1 commit
  11. 26 Jun, 2008 1 commit
  13. 21 Jun, 2008 1 commit
  15. 30 Apr, 2008 2 commits
    • Harvey Harrison's avatar
      mm: remove remaining __FUNCTION__ occurrences · d40cee24
      Harvey Harrison authored 
      
__FUNCTION__ is gcc-specific, use __func__
Signed-off-by: default avatarHarvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      d40cee24
    • Thomas Gleixner's avatar
      infrastructure to debug (dynamic) objects · 3ac7fe5a
      Thomas Gleixner authored 
      
We can see an ever repeating problem pattern with objects of any kind in the
kernel:

1) freeing of active objects
2) reinitialization of active objects

Both problems can be hard to debug because the crash happens at a point where
we have no chance to decode the root cause anymore.  One problem spot are
kernel timers, where the detection of the problem often happens in interrupt
context and usually causes the machine to panic.

While working on a timer related bug report I had to hack specialized code
into the timer subsystem to get a reasonable hint for the root cause.  This
debug hack was fine for temporary use, but far from a mergeable solution due
to the intrusiveness into the timer code.

The code further lacked the ability to detect and report the root cause
instantly and keep the system operational.

Keeping the system operational is important to get hold of the debug
information without special debugging aids like serial consoles and special
knowledge of the bug reporter.

The problems described above are not restricted to timers, but timers tend to
expose it usually in a full system crash.  Other objects are less explosive,
but the symptoms caused by such mistakes can be even harder to debug.

Instead of creating specialized debugging code for the timer subsystem a
generic infrastructure is created which allows developers to verify their code
and provides an easy to enable debug facility for users in case of trouble.

The debugobjects core code keeps track of operations on static and dynamic
objects by inserting them into a hashed list and sanity checking them on
object operations and provides additional checks whenever kernel memory is
freed.

The tracked object operations are:
- initializing an object
- adding an object to a subsystem list
- deleting an object from a subsystem list

Each operation is sanity checked before the operation is executed and the
subsystem specific code can provide a fixup function which allows to prevent
the damage of the operation.  When the sanity check triggers a warning message
and a stack trace is printed.

The list of operations can be extended if the need arises.  For now it's
limited to the requirements of the first user (timers).

The core code enqueues the objects into hash buckets.  The hash index is
generated from the address of the object to simplify the lookup for the check
on kfree/vfree.  Each bucket has it's own spinlock to avoid contention on a
global lock.

The debug code can be compiled in without being active.  The runtime overhead
is minimal and could be optimized by asm alternatives.  A kernel command line
option enables the debugging code.

Thanks to Ingo Molnar for review, suggestions and cleanup patches.
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Cc: Greg KH <greg@kroah.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      3ac7fe5a
  17. 28 Apr, 2008 4 commits
  19. 19 Apr, 2008 1 commit
    • Mike Travis's avatar
      nodemask: use new node_to_cpumask_ptr function · c5f59f08
      Mike Travis authored 
      
  * Use new node_to_cpumask_ptr.  This creates a pointer to the
    cpumask for a given node.  This definition is in mm patch:

	asm-generic-add-node_to_cpumask_ptr-macro.patch

  * Use new set_cpus_allowed_ptr function.

Depends on:
	[mm-patch]: asm-generic-add-node_to_cpumask_ptr-macro.patch
	[sched-devel]: sched: add new set_cpus_allowed_ptr function
	[x86/latest]: x86: add cpus_scnprintf function

Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Greg Banks <gnb@melbourne.sgi.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: default avatarMike Travis <travis@sgi.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      c5f59f08
  21. 26 Mar, 2008 1 commit
  23. 20 Mar, 2008 1 commit
  25. 07 Mar, 2008 3 commits
  27. 14 Feb, 2008 1 commit
  29. 11 Feb, 2008 1 commit
  31. 25 Jan, 2008 2 commits
  33. 24 Jan, 2008 1 commit
  35. 02 Jan, 2008 1 commit
  37. 05 Dec, 2007 1 commit
  39. 30 Nov, 2007 1 commit
  41. 15 Nov, 2007 1 commit
  43. 19 Oct, 2007 1 commit
  45. 18 Oct, 2007 2 commits
  47. 17 Oct, 2007 2 commits
  49. 16 Oct, 2007 4 commits
    • Mel Gorman's avatar
      Group short-lived and reclaimable kernel allocations · e12ba74d
      Mel Gorman authored 
      
This patch marks a number of allocations that are either short-lived such as
network buffers or are reclaimable such as inode allocations.  When something
like updatedb is called, long-lived and unmovable kernel allocations tend to
be spread throughout the address space which increases fragmentation.

This patch groups these allocations together as much as possible by adding a
new MIGRATE_TYPE.  The MIGRATE_RECLAIMABLE type is for allocations that can be
reclaimed on demand, but not moved.  i.e.  they can be migrated by deleting
them and re-reading the information from elsewhere.
Signed-off-by: default avatarMel Gorman <mel@csn.ul.ie>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      e12ba74d
    • Christoph Lameter's avatar
      Categorize GFP flags · 6cb06229
      Christoph Lameter authored 
      
The function of GFP_LEVEL_MASK seems to be unclear.  In order to clear up
the mystery we get rid of it and replace GFP_LEVEL_MASK with 3 sets of GFP
flags:

GFP_RECLAIM_MASK	Flags used to control page allocator reclaim behavior.

GFP_CONSTRAINT_MASK	Flags used to limit where allocations can occur.

GFP_SLAB_BUG_MASK	Flags that the slab allocator BUG()s on.

These replace the uses of GFP_LEVEL mask in the slab allocators and in
vmalloc.c.

The use of the flags not included in these sets may occur as a result of a
slab allocation standing in for a page allocation when constructing scatter
gather lists.  Extraneous flags are cleared and not passed through to the
page allocator.  __GFP_MOVABLE/RECLAIMABLE, __GFP_COLD and __GFP_COMP will
now be ignored if passed to a slab allocator.

Change the allocation of allocator meta data in SLAB and vmalloc to not
pass through flags listed in GFP_CONSTRAINT_MASK.  SLAB already removes the
__GFP_THISNODE flag for such allocations.  Generalize that to also cover
vmalloc.  The use of GFP_CONSTRAINT_MASK also includes __GFP_HARDWALL.

The impact of allocator metadata placement on access latency to the
cachelines of the object itself is minimal since metadata is only
referenced on alloc and free.  The attempt is still made to place the meta
data optimally but we consistently allow fallback both in SLAB and vmalloc
(SLUB does not need to allocate metadata like that).

Allocator metadata may serve multiple in kernel users and thus should not
be subject to the limitations arising from a single allocation context.

[akpm@linux-foundation.org: fix fallback_alloc()]
Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      6cb06229
    • Christoph Lameter's avatar
      Memoryless nodes: Slab support · 04231b30
      Christoph Lameter authored 
      
Slab should not allocate control structures for nodes without memory.  This
may seem to work right now but its unreliable since not all allocations can
fall back due to the use of GFP_THISNODE.

Switching a few for_each_online_node's to N_NORMAL_MEMORY will allow us to
only allocate for nodes that have regular memory.
Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
Acked-by: default avatarNishanth Aravamudan <nacc@us.ibm.com>
Acked-by: default avatarLee Schermerhorn <lee.schermerhorn@hp.com>
Acked-by: default avatarBob Picco <bob.picco@hp.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@skynet.ie>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      04231b30
    • Christoph Lameter's avatar
      Slab allocators: fail if ksize is called with a NULL parameter · ef8b4520
      Christoph Lameter authored 
      
A NULL pointer means that the object was not allocated.  One cannot
determine the size of an object that has not been allocated.  Currently we
return 0 but we really should BUG() on attempts to determine the size of
something nonexistent.

krealloc() interprets NULL to mean a zero sized object.  Handle that
separately in krealloc().
Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
Acked-by: default avatarPekka Enberg <penberg@cs.helsinki.fi>
Cc: Matt Mackall <mpm@selenic.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      ef8b4520
  51. 23 Aug, 2007 1 commit
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