28 Jun, 2006
5 commits
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Runtime debugging functionality for rt-mutexes.
Signed-off-by: Ingo Molnar
Signed-off-by: Thomas Gleixner
Signed-off-by: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add debug_check_no_locks_freed(), as a central inline to add
bad-lock-free-debugging functionality to.Signed-off-by: Ingo Molnar
Signed-off-by: Thomas Gleixner
Signed-off-by: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Make notifier_blocks associated with cpu_notifier as __cpuinitdata.
__cpuinitdata makes sure that the data is init time only unless
CONFIG_HOTPLUG_CPU is defined.Signed-off-by: Chandra Seetharaman
Cc: Ashok Raj
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
In 2.6.17, there was a problem with cpu_notifiers and XFS. I provided a
band-aid solution to solve that problem. In the process, i undid all the
changes you both were making to ensure that these notifiers were available
only at init time (unless CONFIG_HOTPLUG_CPU is defined).We deferred the real fix to 2.6.18. Here is a set of patches that fixes the
XFS problem cleanly and makes the cpu notifiers available only at init time
(unless CONFIG_HOTPLUG_CPU is defined).If CONFIG_HOTPLUG_CPU is defined then cpu notifiers are available at run
time.This patch reverts the notifier_call changes made in 2.6.17
Signed-off-by: Chandra Seetharaman
Cc: Ashok Raj
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Localize poison values into one header file for better documentation and
easier/quicker debugging and so that the same values won't be used for
multiple purposes.Use these constants in core arch., mm, driver, and fs code.
Signed-off-by: Randy Dunlap
Acked-by: Matt Mackall
Cc: Paul Mackerras
Cc: Benjamin Herrenschmidt
Cc: "David S. Miller"
Cc: Andi Kleen
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
23 Jun, 2006
8 commits
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- Move comments for kmalloc to right place, currently it near __do_kmalloc
- Comments for kzalloc
- More detailed comments for kmalloc
- Appearance of "kmalloc" and "kzalloc" man pages after "make mandocs"
[rdunlap@xenotime.net: simplification]
Signed-off-by: Paul Drynoff
Acked-by: Randy Dunlap
Cc: Pekka Enberg
Cc: Manfred Spraul
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The SLAB bootstrap code assumes that the first two kmalloc caches created
(the INDEX_AC and INDEX_L3 kmalloc caches) wont be off-slab. But due to AC
and L3 structure size increase in lockdep, one of them ended up being
off-slab, and subsequently crashing with:Unable to handle kernel NULL pointer dereference at 0000000000000000 RIP:
[] kmem_cache_alloc+0x26/0x7dThe fix is to introduce a bootstrap flag and to use it to prevent off-slab
caches being created so early during bootup.(The calculation for off-slab caches is quite complex so i didnt want to
complicate things with introducing yet another INDEX_ calculation, the flag
approach is simpler and smaller.)Signed-off-by: Ingo Molnar
Cc: Manfred Spraul
Cc: Pekka Enberg
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Passing an invalid pointer to kfree() and kmem_cache_free() is likely to
cause bad memory corruption or even take down the whole system because the
bad pointer is likely reused immediately due to the per-CPU caches. Until
now, we don't do any verification for this if CONFIG_DEBUG_SLAB is
disabled.As suggested by Linus, add PageSlab check to page_to_cache() and
page_to_slab() to verify pointers passed to kfree(). Also, move the
stronger check from cache_free_debugcheck() to kmem_cache_free() to ensure
the passed pointer actually belongs to the cache we're about to free the
object.For page_to_cache() and page_to_slab(), the assertions should have
virtually no extra cost (two instructions, no data cache pressure) and for
kmem_cache_free() the overhead should be minimal.Signed-off-by: Pekka Enberg
Cc: Manfred Spraul
Cc: Christoph Lameter
Cc: Linus Torvalds
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
At present our slab debugging tells us that it detected a double-free or
corruption - it does not distinguish between them. Sometimes it's useful
to be able to differentiate between these two types of information.Add double-free detection to redzone verification when freeing an object.
As explained by Manfred, when we are freeing an object, both redzones
should be RED_ACTIVE. However, if both are RED_INACTIVE, we are trying to
free an object that was already free'd.Signed-off-by: Manfred Spraul
Signed-off-by: Pekka Enberg
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Use the _entry variant everywhere to clean the code up a tiny bit.
Signed-off-by: Christoph Hellwig
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The last ifdef addition hit the ugliness treshold on this functions, so:
- rename the variable i to nr_pages so it's somewhat descriptive
- remove the addr variable and do the page_address call at the very end
- instead of ifdef'ing the whole alloc_pages_node call just make the
__GFP_COMP addition to flags conditional
- rewrite the __GFP_COMP comment to make senseSigned-off-by: Christoph Hellwig
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Clean up slab allocator page mapping a bit. The memory allocated for a
slab is physically contiguous so it is okay to assume struct pages are too
so kill the long-standing comment. Furthermore, rename set_slab_attr to
slab_map_pages and add a comment explaining why its needed.Signed-off-by: Pekka Enberg
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Move alien object freeing to cache_free_alien() to reduce #ifdef clutter in
__cache_free().Signed-off-by: Pekka Enberg
Acked-by: Christoph Lameter
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
03 Jun, 2006
1 commit
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mm/slab.c's offlab_limit logic is totally broken.
Firstly, "offslab_limit" is a global variable while it should either be
calculated in situ or should be passed in as a parameter.Secondly, the more serious problem with it is that the condition for
calculating it:if (!(OFF_SLAB(sizes->cs_cachep))) {
offslab_limit = sizes->cs_size - sizeof(struct slab);
offslab_limit /= sizeof(kmem_bufctl_t);is in total disconnect with the condition that makes use of it:
/* More than offslab_limit objects will cause problems */
if ((flags & CFLGS_OFF_SLAB) && num > offslab_limit)
break;but due to offslab_limit being a global variable this breakage was
hidden.Up until lockdep came along and perturbed the slab sizes sufficiently so
that the first off-slab cache would still see a (non-calculated) zero
value for offslab_limit and would panic with:kmem_cache_create: couldn't create cache size-512.
Call Trace:
[] show_trace+0x96/0x1c8
[] dump_stack+0x13/0x15
[] panic+0x39/0x21a
[] kmem_cache_create+0x5a0/0x5d0
[] kmem_cache_init+0x193/0x379
[] start_kernel+0x17f/0x218
[] _sinittext+0x263/0x26aKernel panic - not syncing: kmem_cache_create(): failed to create slab `size-512'
Paolo Ornati's config on x86_64 managed to trigger it.
The fix is to move the calculation to the place that makes use of it.
This also makes slab.o 54 bytes smaller.Btw., the check itself is quite silly. Its intention is to test whether
the number of objects per slab would be higher than the number of slab
control pointers possible. In theory it could be triggered: if someone
tried to allocate 4-byte objects cache and explicitly requested with
CFLGS_OFF_SLAB. So i kept the check.Out of historic interest i checked how old this bug was and it's
ancient, 10 years old! It is the oldest hidden and then truly triggering
bugs i ever saw being fixed in the kernel!Signed-off-by: Ingo Molnar
Signed-off-by: Linus Torvalds
16 May, 2006
2 commits
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With CONFIG_NUMA set, kmem_cache_destroy() may fail and say "Can't
free all objects." The problem is caused by sequences such as the
following (suppose we are on a NUMA machine with two nodes, 0 and 1):* Allocate an object from cache on node 0.
* Free the object on node 1. The object is put into node 1's alien
array_cache for node 0.
* Call kmem_cache_destroy(), which ultimately ends up in __cache_shrink().
* __cache_shrink() does drain_cpu_caches(), which loops through all nodes.
For each node it drains the shared array_cache and then handles the
alien array_cache for the other node.However this means that node 0's shared array_cache will be drained,
and then node 1 will move the contents of its alien[0] array_cache
into that same shared array_cache. node 0's shared array_cache is
never looked at again, so the objects left there will appear to be in
use when __cache_shrink() calls __node_shrink() for node 0. So
__node_shrink() will return 1 and kmem_cache_destroy() will fail.This patch fixes this by having drain_cpu_caches() do
drain_alien_cache() on every node before it does drain_array() on the
nodes' shared array_caches.The problem was originally reported by Or Gerlitz .
Signed-off-by: Roland Dreier
Acked-by: Christoph Lameter
Acked-by: Pekka Enberg
Signed-off-by: Linus Torvalds -
slab_is_available() indicates slab based allocators are available for use.
SPARSEMEM code needs to know this as it can be called at various times
during the boot process.Signed-off-by: Mike Kravetz
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
29 Apr, 2006
1 commit
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transfer_objects should only be called when all of the cpus in the
node are online. CPU_DEAD notifier callback marks l3->shared to NULL.Signed-off-by: Jacob Shin
Signed-off-by: Linus Torvalds
26 Apr, 2006
1 commit
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Few of the notifier_chain_register() callers use __init in the definition
of notifier_call. It is incorrect as the function definition should be
available after the initializations (they do not unregister them during
initializations).This patch fixes all such usages to _not_ have the notifier_call __init
section.Signed-off-by: Chandra Seetharaman
Signed-off-by: Linus Torvalds
11 Apr, 2006
3 commits
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The earlier patch to consolidate mmu and nommu page allocation and
refcounting by using compound pages for nommu allocations had a bug:
kmalloc slabs who's pages were initially allocated by a non-__GFP_COMP
allocator could be passed into mm/nommu.c kmalloc allocations which really
wanted __GFP_COMP underlying pages. Fix that by having nommu pass
__GFP_COMP to all higher order slab allocations.Signed-off-by: Luke Yang
Acked-by: Nick Piggin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add a statistics counter which is incremented everytime the alien cache
overflows. alien_cache limit is hardcoded to 12 right now. We can use
this statistics to tune alien cache if needed in the future.Signed-off-by: Alok N Kataria
Signed-off-by: Ravikiran Thirumalai
Signed-off-by: Shai Fultheim
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Allocate off-slab slab descriptors from node local memory.
Signed-off-by: Alok N Kataria
Signed-off-by: Ravikiran Thirumalai
Signed-off-by: Shai Fultheim
Acked-by: Christoph Lameter
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
02 Apr, 2006
1 commit
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this changes if() BUG(); constructs to BUG_ON() which is
cleaner, contains unlikely() and can better optimized away.Signed-off-by: Eric Sesterhenn
Signed-off-by: Adrian Bunk
29 Mar, 2006
1 commit
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replaces for_each_cpu with for_each_possible_cpu().
Signed-off-by: KAMEZAWA Hiroyuki
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
26 Mar, 2006
7 commits
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We have had this memory leak for a while now. The situation is complicated
by the use of alloc_kmemlist() as a function to resize various caches by
do_tune_cpucache().What we do here is first of all make sure that we deallocate properly in
the loop over all the nodes.If we are just resizing caches then we can simply return with -ENOMEM if an
allocation fails.If the cache is new then we need to rollback and remove all earlier
allocations.We detect that a cache is new by checking if the link to the global cache
chain has been setup. This is a bit hackish ....(also fix up too overlong lines that I added in the last patch...)
Signed-off-by: Christoph Lameter
Cc: Jesper Juhl
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Inspired by Jesper Juhl's patch from today
1. Get rid of err
We do not set it to anything else but zero.2. Drop the CONFIG_NUMA stuff.
There are definitions for alloc_alien_cache and free_alien_cache()
that do the right thing for the non NUMA case.3. Better naming of variables.
4. Remove redundant cachep->nodelists[node] expressions.
Signed-off-by: Christoph Lameter
Signed-off-by: Jesper Juhl
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
__drain_alien_cache() currently drains objects by freeing them to the
(remote) freelists of the original node. However, each node also has a
shared list containing objects to be used on any processor of that node.
We can avoid a number of remote node accesses by copying the pointers to
the free objects directly into the remote shared array.And while we are at it: Skip alien draining if the alien cache spinlock is
already taken.Kiran reported that this is a performance benefit.
Signed-off-by: Christoph Lameter
Cc: Pekka Enberg
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
slabr_objects() can be used to transfer objects between various object
caches of the slab allocator. It is currently only used during
__cache_alloc() to retrieve elements from the shared array. We will be
using it soon to transfer elements from the alien caches to the remote
shared array.Signed-off-by: Christoph Lameter
Cc: Pekka Enberg
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Convert mm/ to use the new kmem_cache_zalloc allocator.
Signed-off-by: Pekka Enberg
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Introduce a memory-zeroing variant of kmem_cache_alloc. The allocator
already exits in XFS and there are potential users for it so this patch
makes the allocator available for the general public.Signed-off-by: Pekka Enberg
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Implement /proc/slab_allocators. It produces output like:
idr_layer_cache: 80 idr_pre_get+0x33/0x4e
buffer_head: 2555 alloc_buffer_head+0x20/0x75
mm_struct: 9 mm_alloc+0x1e/0x42
mm_struct: 20 dup_mm+0x36/0x370
vm_area_struct: 384 dup_mm+0x18f/0x370
vm_area_struct: 151 do_mmap_pgoff+0x2e0/0x7c3
vm_area_struct: 1 split_vma+0x5a/0x10e
vm_area_struct: 11 do_brk+0x206/0x2e2
vm_area_struct: 2 copy_vma+0xda/0x142
vm_area_struct: 9 setup_arg_pages+0x99/0x214
fs_cache: 8 copy_fs_struct+0x21/0x133
fs_cache: 29 copy_process+0xf38/0x10e3
files_cache: 30 alloc_files+0x1b/0xcf
signal_cache: 81 copy_process+0xbaa/0x10e3
sighand_cache: 77 copy_process+0xe65/0x10e3
sighand_cache: 1 de_thread+0x4d/0x5f8
anon_vma: 241 anon_vma_prepare+0xd9/0xf3
size-2048: 1 add_sect_attrs+0x5f/0x145
size-2048: 2 journal_init_revoke+0x99/0x302
size-2048: 2 journal_init_revoke+0x137/0x302
size-2048: 2 journal_init_inode+0xf9/0x1c4Cc: Manfred Spraul
Cc: Alexander Nyberg
Cc: Pekka Enberg
Cc: Christoph Lameter
Cc: Ravikiran Thirumalai
Signed-off-by: Al Viro
DESC
slab-leaks3-locking-fix
EDESC
From: Andrew MortonUpdate for slab-remove-cachep-spinlock.patch
Cc: Al Viro
Cc: Manfred Spraul
Cc: Alexander Nyberg
Cc: Pekka Enberg
Cc: Christoph Lameter
Cc: Ravikiran Thirumalai
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
24 Mar, 2006
3 commits
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The hook in the slab cache allocation path to handle cpuset memory
spreading for tasks in cpusets with 'memory_spread_slab' enabled has a
modest performance bug. The hook calls into the memory spreading handler
alternate_node_alloc() if either of 'memory_spread_slab' or
'memory_spread_page' is enabled, even though the handler does nothing
(albeit harmlessly) for the page caseFix - drop PF_SPREAD_PAGE from the set of flag bits that are used to
trigger a call to alternate_node_alloc().The page case is handled by separate hooks -- see the calls conditioned on
cpuset_do_page_mem_spread() in mm/filemap.cSigned-off-by: Paul Jackson
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The hooks in the slab cache allocator code path for support of NUMA
mempolicies and cpuset memory spreading are in an important code path. Many
systems will use neither feature.This patch optimizes those hooks down to a single check of some bits in the
current tasks task_struct flags. For non NUMA systems, this hook and related
code is already ifdef'd out.The optimization is done by using another task flag, set if the task is using
a non-default NUMA mempolicy. Taking this flag bit along with the
PF_SPREAD_PAGE and PF_SPREAD_SLAB flag bits added earlier in this 'cpuset
memory spreading' patch set, one can check for the combination of any of these
special case memory placement mechanisms with a single test of the current
tasks task_struct flags.This patch also tightens up the code, to save a few bytes of kernel text
space, and moves some of it out of line. Due to the nested inlines called
from multiple places, we were ending up with three copies of this code, which
once we get off the main code path (for local node allocation) seems a bit
wasteful of instruction memory.Signed-off-by: Paul Jackson
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Provide the slab cache infrastructure to support cpuset memory spreading.
See the previous patches, cpuset_mem_spread, for an explanation of cpuset
memory spreading.This patch provides a slab cache SLAB_MEM_SPREAD flag. If set in the
kmem_cache_create() call defining a slab cache, then any task marked with the
process state flag PF_MEMSPREAD will spread memory page allocations for that
cache over all the allowed nodes, instead of preferring the local (faulting)
node.On systems not configured with CONFIG_NUMA, this results in no change to the
page allocation code path for slab caches.On systems with cpusets configured in the kernel, but the "memory_spread"
cpuset option not enabled for the current tasks cpuset, this adds a call to a
cpuset routine and failed bit test of the processor state flag PF_SPREAD_SLAB.For tasks so marked, a second inline test is done for the slab cache flag
SLAB_MEM_SPREAD, and if that is set and if the allocation is not
in_interrupt(), this adds a call to to a cpuset routine that computes which of
the tasks mems_allowed nodes should be preferred for this allocation.==> This patch adds another hook into the performance critical
code path to allocating objects from the slab cache, in the
____cache_alloc() chunk, below. The next patch optimizes this
hook, reducing the impact of the combined mempolicy plus memory
spreading hooks on this critical code path to a single check
against the tasks task_struct flags word.This patch provides the generic slab flags and logic needed to apply memory
spreading to a particular slab.A subsequent patch will mark a few specific slab caches for this placement
policy.Signed-off-by: Paul Jackson
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
22 Mar, 2006
7 commits
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The alien cache rotor in mm/slab.c assumes that the first online node is
node 0. Eventually for some archs, especially with hotplug, this will no
longer be true.Fix the interleave rotor to handle the general case of node numbering.
Signed-off-by: Paul Jackson
Acked-by: Christoph Lameter
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The list_lock also protects the shared array and we call drain_array() with
the shared array. Therefore we cannot go as far as I wanted to but have to
take the lock in a way so that it also protects the array_cache in
drain_pages.(Note: maybe we should make the array_cache locking more consistent? I.e.
always take the array cache lock for shared arrays and disable interrupts
for the per cpu arrays?)Signed-off-by: Christoph Lameter
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Remove drain_array_locked and use that opportunity to limit the time the l3
lock is taken further.Signed-off-by: Christoph Lameter
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
And a parameter to drain_array to control the freeing of all objects and
then use drain_array() to replace instances of drain_array_locked with
drain_array. Doing so will avoid taking locks in those locations if the
arrays are empty.Signed-off-by: Christoph Lameter
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
cache_reap takes the l3->list_lock (disabling interrupts) unconditionally
and then does a few checks and maybe does some cleanup. This patch makes
cache_reap() only take the lock if there is work to do and then the lock is
taken and released for each cleaning action.The checking of when to do the next reaping is done without any locking and
becomes racy. Should not matter since reaping can also be skipped if the
slab mutex cannot be acquired.The same is true for the touched processing. If we get this wrong once in
awhile then we will mistakenly clean or not clean the shared cache. This
will impact performance slightly.Note that the additional drain_array() function introduced here will fall
out in a subsequent patch since array cleaning will now be very similar
from all callers.Signed-off-by: Christoph Lameter
Cc: Pekka Enberg
Cc: Manfred Spraul
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Now that compound page handling is properly fixed in the VM, move nommu
over to using compound pages rather than rolling their own refcounting.nommu vm page refcounting is broken anyway, but there is no need to have
divergent code in the core VM now, nor when it gets fixed.Signed-off-by: Nick Piggin
Cc: David Howells(Needs testing, please).
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Slab duplicates on_each_cpu().
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
