Extract the function to determine the index of the slab within
the array of kmalloc caches as well as a function to determine
maximum object size from the nr of the kmalloc slab.

This is used here only to simplify slub bootstrap but will
be used later also for SLAB.
Acked-by: NGlauber Costa <glommer@parallels.com>
Signed-off-by: NChristoph Lameter <cl@linux.com>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

SLUB allows us to tune a particular cache behavior with sysfs-based
tunables.  When creating a new memcg cache copy, we'd like to preserve any
tunables the parent cache already had.

This can be done by tapping into the store attribute function provided by
the allocator.  We of course don't need to mess with read-only fields.
Since the attributes can have multiple types and are stored internally by
sysfs, the best strategy is to issue a ->show() in the root cache, and
then ->store() in the memcg cache.

The drawback of that, is that sysfs can allocate up to a page in buffering
for show(), that we are likely not to need, but also can't guarantee.  To
avoid always allocating a page for that, we can update the caches at store
time with the maximum attribute size ever stored to the root cache.  We
will then get a buffer big enough to hold it.  The corolary to this, is
that if no stores happened, nothing will be propagated.

It can also happen that a root cache has its tunables updated during
normal system operation.  In this case, we will propagate the change to
all caches that are already active.

[akpm@linux-foundation.org: tweak code to avoid __maybe_unused]
Signed-off-by: NGlauber Costa <glommer@parallels.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Frederic Weisbecker <fweisbec@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: JoonSoo Kim <js1304@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Rik van Riel <riel@redhat.com>
Cc: Suleiman Souhlal <suleiman@google.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We are able to match a cache allocation to a particular memcg.  If the
task doesn't change groups during the allocation itself - a rare event,
this will give us a good picture about who is the first group to touch a
cache page.

This patch uses the now available infrastructure by calling
memcg_kmem_get_cache() before all the cache allocations.
Signed-off-by: NGlauber Costa <glommer@parallels.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Frederic Weisbecker <fweisbec@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: JoonSoo Kim <js1304@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Rik van Riel <riel@redhat.com>
Cc: Suleiman Souhlal <suleiman@google.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

For the kmem slab controller, we need to record some extra information in
the kmem_cache structure.
Signed-off-by: NGlauber Costa <glommer@parallels.com>
Signed-off-by: NSuleiman Souhlal <suleiman@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Frederic Weisbecker <fweisbec@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: JoonSoo Kim <js1304@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Rik van Riel <riel@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Define a struct that describes common fields used in all slab allocators.
A slab allocator either uses the common definition (like SLOB) or is
required to provide members of kmem_cache with the definition given.

After that it will be possible to share code that
only operates on those fields of kmem_cache.

The patch basically takes the slob definition of kmem cache and
uses the field namees for the other allocators.

It also standardizes the names used for basic object lengths in
allocators:

object_size	Struct size specified at kmem_cache_create. Basically
		the payload expected to be used by the subsystem.

size		The size of memory allocator for each object. This size
		is larger than object_size and includes padding, alignment
		and extra metadata for each object (f.e. for debugging
		and rcu).
Signed-off-by: NChristoph Lameter <cl@linux.com>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

The node field is always page_to_nid(c->page). So its rather easy to
replace. Note that there maybe slightly more overhead in various hot paths
due to the need to shift the bits from page->flags. However, that is mostly
compensated for by a smaller footprint of the kmem_cache_cpu structure (this
patch reduces that to 3 words per cache) which allows better caching.
Signed-off-by: NChristoph Lameter <cl@linux.com>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

If a header file is making use of BUG, BUG_ON, BUILD_BUG_ON, or any
other BUG variant in a static inline (i.e. not in a #define) then
that header really should be including <linux/bug.h> and not just
expecting it to be implicitly present.

We can make this change risk-free, since if the files using these
headers didn't have exposure to linux/bug.h already, they would have
been causing compile failures/warnings.
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

This patch split the cpu_partial_free into 2 parts: cpu_partial_node, PCP refilling
times from node partial; and same name cpu_partial_free, PCP refilling times in
slab_free slow path. A new statistic 'cpu_partial_drain' is added to get PCP
drain to node partial times. These info are useful when do PCP tunning.

The slabinfo.c code is unchanged, since cpu_partial_node is not on slow path.
Signed-off-by: NAlex Shi <alex.shi@intel.com>
Acked-by: NChristoph Lameter <cl@linux.com>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

Correct comment errors, that mistake cpu partial objects number as pages
number, may make reader misunderstand.
Signed-off-by: NAlex Shi <alex.shi@intel.com>
Reviewed-by: NChristoph Lameter <cl@linux.com>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

Allow filling out the rest of the kmem_cache_cpu cacheline with pointers to
partial pages. The partial page list is used in slab_free() to avoid
per node lock taking.

In __slab_alloc() we can then take multiple partial pages off the per
node partial list in one go reducing node lock pressure.

We can also use the per cpu partial list in slab_alloc() to avoid scanning
partial lists for pages with free objects.

The main effect of a per cpu partial list is that the per node list_lock
is taken for batches of partial pages instead of individual ones.

Potential future enhancements:

1. The pickup from the partial list could be perhaps be done without disabling
   interrupts with some work. The free path already puts the page into the
   per cpu partial list without disabling interrupts.

2. __slab_free() may have some code paths that could use optimization.

Performance:

				Before		After
./hackbench 100 process 200000
				Time: 1953.047	1564.614
./hackbench 100 process 20000
				Time: 207.176   156.940
./hackbench 100 process 20000
				Time: 204.468	156.940
./hackbench 100 process 20000
				Time: 204.879	158.772
./hackbench 10 process 20000
				Time: 20.153	15.853
./hackbench 10 process 20000
				Time: 20.153	15.986
./hackbench 10 process 20000
				Time: 19.363	16.111
./hackbench 1 process 20000
				Time: 2.518	2.307
./hackbench 1 process 20000
				Time: 2.258	2.339
./hackbench 1 process 20000
				Time: 2.864	2.163
Signed-off-by: NChristoph Lameter <cl@linux.com>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

This is for tracking down suspect memory usage.
Acked-by: NChristoph Lameter <cl@linux.com>
Signed-off-by: NBen Greear <greearb@candelatech.com>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

Make deactivation occur implicitly while checking out the current freelist.

This avoids one cmpxchg operation on a slab that is now fully in use.
Signed-off-by: NChristoph Lameter <cl@linux.com>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

Slub reloads the per cpu slab if the page does not satisfy the NUMA condition. Track
those reloads since doing so has a performance impact.
Signed-off-by: NChristoph Lameter <cl@linux.com>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

Add a function that operates on the second doubleword in the page struct
and manipulates the object counters, the freelist and the frozen attribute.
Signed-off-by: NChristoph Lameter <cl@linux.com>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

Every slab has its on alignment definition in include/linux/sl?b_def.h. Extract those
and define a common set in include/linux/slab.h.

SLOB: As notes sometimes we need double word alignment on 32 bit. This gives all
structures allocated by SLOB a unsigned long long alignment like the others do.

SLAB: If ARCH_SLAB_MINALIGN is not set SLAB would set ARCH_SLAB_MINALIGN to
zero meaning no alignment at all. Give it the default unsigned long long alignment.
Signed-off-by: NChristoph Lameter <cl@linux.com>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

kmalloc_index() currently returns -1 if the PAGE_SIZE is larger than 2M
which seems to cause some concern since the callers do not check for -1.

Insert a BUG() and add a comment to the -1 explaining that the code
cannot be reached.
Signed-off-by: NChristoph Lameter <cl@linux.com>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

Remove the #ifdefs. This means that the irqsafe_cpu_cmpxchg_double() is used
everywhere.

There may be performance implications since:

A. We now have to manage a transaction ID for all arches

B. The interrupt holdoff for arches not supporting CONFIG_CMPXCHG_LOCAL is reduced
to a very short irqoff section.

There are no multiple irqoff/irqon sequences as a result of this change. Even in the fallback
case we only have to do one disable and enable like before.
Signed-off-by: NChristoph Lameter <cl@linux.com>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

Add some statistics for debugging.
Signed-off-by: NChristoph Lameter <cl@linux.com>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

There is no "struct" for slub's slab, it shares with struct page.
But struct page is very small, it is insufficient when we need
to add some metadata for slab.

So we add a field "reserved" to struct kmem_cache, when a slab
is allocated, kmem_cache->reserved bytes are automatically reserved
at the end of the slab for slab's metadata.

Changed from v1:
	Export the reserved field via sysfs
Acked-by: NChristoph Lameter <cl@linux.com>
Signed-off-by: NLai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

Use the this_cpu_cmpxchg_double functionality to implement a lockless
allocation algorithm on arches that support fast this_cpu_ops.

Each of the per cpu pointers is paired with a transaction id that ensures
that updates of the per cpu information can only occur in sequence on
a certain cpu.

A transaction id is a "long" integer that is comprised of an event number
and the cpu number. The event number is incremented for every change to the
per cpu state. This means that the cmpxchg instruction can verify for an
update that nothing interfered and that we are updating the percpu structure
for the processor where we picked up the information and that we are also
currently on that processor when we update the information.

This results in a significant decrease of the overhead in the fastpaths. It
also makes it easy to adopt the fast path for realtime kernels since this
is lockless and does not require the use of the current per cpu area
over the critical section. It is only important that the per cpu area is
current at the beginning of the critical section and at the end.

So there is no need even to disable preemption.

Test results show that the fastpath cycle count is reduced by up to ~ 40%
(alloc/free test goes from ~140 cycles down to ~80). The slowpath for kfree
adds a few cycles.

Sadly this does nothing for the slowpath which is where the main issues with
performance in slub are but the best case performance rises significantly.
(For that see the more complex slub patches that require cmpxchg_double)

Kmalloc: alloc/free test

Before:

10000 times kmalloc(8)/kfree -> 134 cycles
10000 times kmalloc(16)/kfree -> 152 cycles
10000 times kmalloc(32)/kfree -> 144 cycles
10000 times kmalloc(64)/kfree -> 142 cycles
10000 times kmalloc(128)/kfree -> 142 cycles
10000 times kmalloc(256)/kfree -> 132 cycles
10000 times kmalloc(512)/kfree -> 132 cycles
10000 times kmalloc(1024)/kfree -> 135 cycles
10000 times kmalloc(2048)/kfree -> 135 cycles
10000 times kmalloc(4096)/kfree -> 135 cycles
10000 times kmalloc(8192)/kfree -> 144 cycles
10000 times kmalloc(16384)/kfree -> 754 cycles

After:

10000 times kmalloc(8)/kfree -> 78 cycles
10000 times kmalloc(16)/kfree -> 78 cycles
10000 times kmalloc(32)/kfree -> 82 cycles
10000 times kmalloc(64)/kfree -> 88 cycles
10000 times kmalloc(128)/kfree -> 79 cycles
10000 times kmalloc(256)/kfree -> 79 cycles
10000 times kmalloc(512)/kfree -> 85 cycles
10000 times kmalloc(1024)/kfree -> 82 cycles
10000 times kmalloc(2048)/kfree -> 82 cycles
10000 times kmalloc(4096)/kfree -> 85 cycles
10000 times kmalloc(8192)/kfree -> 82 cycles
10000 times kmalloc(16384)/kfree -> 706 cycles

Kmalloc: Repeatedly allocate then free test

Before:

10000 times kmalloc(8) -> 211 cycles kfree -> 113 cycles
10000 times kmalloc(16) -> 174 cycles kfree -> 115 cycles
10000 times kmalloc(32) -> 235 cycles kfree -> 129 cycles
10000 times kmalloc(64) -> 222 cycles kfree -> 120 cycles
10000 times kmalloc(128) -> 343 cycles kfree -> 139 cycles
10000 times kmalloc(256) -> 827 cycles kfree -> 147 cycles
10000 times kmalloc(512) -> 1048 cycles kfree -> 272 cycles
10000 times kmalloc(1024) -> 2043 cycles kfree -> 528 cycles
10000 times kmalloc(2048) -> 4002 cycles kfree -> 571 cycles
10000 times kmalloc(4096) -> 7740 cycles kfree -> 628 cycles
10000 times kmalloc(8192) -> 8062 cycles kfree -> 850 cycles
10000 times kmalloc(16384) -> 8895 cycles kfree -> 1249 cycles

After:

10000 times kmalloc(8) -> 190 cycles kfree -> 129 cycles
10000 times kmalloc(16) -> 76 cycles kfree -> 123 cycles
10000 times kmalloc(32) -> 126 cycles kfree -> 124 cycles
10000 times kmalloc(64) -> 181 cycles kfree -> 128 cycles
10000 times kmalloc(128) -> 310 cycles kfree -> 140 cycles
10000 times kmalloc(256) -> 809 cycles kfree -> 165 cycles
10000 times kmalloc(512) -> 1005 cycles kfree -> 269 cycles
10000 times kmalloc(1024) -> 1999 cycles kfree -> 527 cycles
10000 times kmalloc(2048) -> 3967 cycles kfree -> 570 cycles
10000 times kmalloc(4096) -> 7658 cycles kfree -> 637 cycles
10000 times kmalloc(8192) -> 8111 cycles kfree -> 859 cycles
10000 times kmalloc(16384) -> 8791 cycles kfree -> 1173 cycles
Signed-off-by: NChristoph Lameter <cl@linux.com>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

It is used in unfreeze_slab() which is a performance critical
function.
Signed-off-by: NChristoph Lameter <cl@linux.com>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

Having the trace calls defined in the always inlined kmalloc functions
in include/linux/slub_def.h causes a lot of code duplication as the
trace functions get instantiated for each kamalloc call site. This can
simply be removed by pushing the trace calls down into the functions in
slub.c.

On my x86_64 built this patch shrinks the code size of the kernel by
approx 36K and also shrinks the code size of many modules -- too many to
list here ;)

size vmlinux (2.6.36) reports
       text        data     bss     dec     hex filename
    5410611	 743172	 828928	6982711	 6a8c37	vmlinux
    5373738	 744244	 828928	6946910	 6a005e	vmlinux + patch

The resulting kernel has had some testing & kmalloc trace still seems to
work.

This patch
- moves trace_kmalloc out of the inlined kmalloc() and pushes it down
into kmem_cache_alloc_trace() so this it only get instantiated once.

- rename kmem_cache_alloc_notrace()  to kmem_cache_alloc_trace() to
indicate that now is does have tracing. (maybe this would better being
called something like kmalloc_kmem_cache ?)

- adds a new function kmalloc_order() to handle allocation and tracing
of large allocations of page order.

- removes tracing from the inlined kmalloc_large() replacing them with a
call to kmalloc_order();

- move tracing out of inlined kmalloc_node() and pushing it down into
kmem_cache_alloc_node_trace

- rename kmem_cache_alloc_node_notrace() to
kmem_cache_alloc_node_trace()

- removes the include of trace/events/kmem.h from slub_def.h.

v2
- keep kmalloc_order_trace inline when !CONFIG_TRACE
Signed-off-by: NRichard Kennedy <richard@rsk.demon.co.uk>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

Currently disabling CONFIG_SLUB_DEBUG also disabled SYSFS support meaning
that the slabs cannot be tuned without DEBUG.

Make SYSFS support independent of CONFIG_SLUB_DEBUG
Signed-off-by: NChristoph Lameter <cl@linux.com>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

Reduce the #ifdefs and simplify bootstrap by making SMP and NUMA as much alike
as possible. This means that there will be an additional indirection to get to
the kmem_cache_node field under SMP.
Acked-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NChristoph Lameter <cl@linux.com>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

kmalloc caches are statically defined and may take up a lot of space just
because the sizes of the node array has to be dimensioned for the largest
node count supported.

This patch makes the size of the kmem_cache structure dynamic throughout by
creating a kmem_cache slab cache for the kmem_cache objects. The bootstrap
occurs by allocating the initial one or two kmem_cache objects from the
page allocator.

C2->C3
	- Fix various issues indicated by David
	- Make create kmalloc_cache return a kmem_cache * pointer.
Acked-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NChristoph Lameter <cl@linux-foundation.org>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

Now each architecture has the own dma_get_cache_alignment implementation.

dma_get_cache_alignment returns the minimum DMA alignment.  Architectures
define it as ARCH_KMALLOC_MINALIGN (it's used to make sure that malloc'ed
buffer is DMA-safe; the buffer doesn't share a cache with the others).  So
we can unify dma_get_cache_alignment implementations.

This patch:

dma_get_cache_alignment() needs to know if an architecture defines
ARCH_KMALLOC_MINALIGN or not (needs to know if architecture has DMA
alignment restriction).  However, slab.h define ARCH_KMALLOC_MINALIGN if
architectures doesn't define it.

Let's rename ARCH_KMALLOC_MINALIGN to ARCH_DMA_MINALIGN.
ARCH_KMALLOC_MINALIGN is used only in the internals of slab/slob/slub
(except for crypto).
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

kmem_cache->cpu_slab is a percpu pointer but was missing __percpu
markup.  Add it.
Signed-off-by: NNamhyung Kim <namhyung@gmail.com>
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

We have been resisting new ftrace plugins and removing existing
ones, and kmemtrace has been superseded by kmem trace events
and perf-kmem, so we remove it.
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Acked-by: NPekka Enberg <penberg@cs.helsinki.fi>
Acked-by: NEduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>
[ remove kmemtrace from the makefile, handle slob too ]
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>

Commit 756dee75 ("SLUB: Get rid of dynamic DMA
kmalloc cache allocation") makes S390 run out of kmalloc caches.  Increase the
number of kmalloc caches to a safe size.

Cc: <stable@kernel.org> [ .33 and .34 ]
Reported-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Tested-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NChristoph Lameter <cl@linux-foundation.org>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

This patch is meant to improve the performance of SLUB by moving the local
kmem_cache_node lock into it's own cacheline separate from kmem_cache.
This is accomplished by simply removing the local_node when NUMA is enabled.

On my system with 2 nodes I saw around a 5% performance increase w/
hackbench times dropping from 6.2 seconds to 5.9 seconds on average.  I
suspect the performance gain would increase as the number of nodes
increases, but I do not have the data to currently back that up.

Bugzilla-Reference: http://bugzilla.kernel.org/show_bug.cgi?id=15713
Cc: <stable@kernel.org>
Reported-by: NAlex Shi <alex.shi@intel.com>
Tested-by: NAlex Shi <alex.shi@intel.com>
Acked-by: NYanmin Zhang <yanmin_zhang@linux.intel.com>
Acked-by: NChristoph Lameter <cl@linux-foundation.org>
Signed-off-by: NAlexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

Acked-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

Remove the fields in struct kmem_cache_cpu that were used to cache data from
struct kmem_cache when they were in different cachelines. The cacheline that
holds the per cpu array pointer now also holds these values. We can cut down
the struct kmem_cache_cpu size to almost half.

The get_freepointer() and set_freepointer() functions that used to be only
intended for the slow path now are also useful for the hot path since access
to the size field does not require accessing an additional cacheline anymore.
This results in consistent use of functions for setting the freepointer of
objects throughout SLUB.

Also we initialize all possible kmem_cache_cpu structures when a slab is
created. No need to initialize them when a processor or node comes online.
Signed-off-by: NChristoph Lameter <cl@linux-foundation.org>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

Dynamic DMA kmalloc cache allocation is troublesome since the
new percpu allocator does not support allocations in atomic contexts.
Reserve some statically allocated kmalloc_cpu structures instead.
Signed-off-by: NChristoph Lameter <cl@linux-foundation.org>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

Using per cpu allocations removes the needs for the per cpu arrays in the
kmem_cache struct. These could get quite big if we have to support systems
with thousands of cpus. The use of this_cpu_xx operations results in:

1. The size of kmem_cache for SMP configuration shrinks since we will only
   need 1 pointer instead of NR_CPUS. The same pointer can be used by all
   processors. Reduces cache footprint of the allocator.

2. We can dynamically size kmem_cache according to the actual nodes in the
   system meaning less memory overhead for configurations that may potentially
   support up to 1k NUMA nodes / 4k cpus.

3. We can remove the diddle widdle with allocating and releasing of
   kmem_cache_cpu structures when bringing up and shutting down cpus. The cpu
   alloc logic will do it all for us. Removes some portions of the cpu hotplug
   functionality.

4. Fastpath performance increases since per cpu pointer lookups and
   address calculations are avoided.

V7-V8
- Convert missed get_cpu_slab() under CONFIG_SLUB_STATS
Signed-off-by: NChristoph Lameter <cl@linux-foundation.org>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

Define kmem_trace_alloc_{,node}_notrace() if CONFIG_TRACING is
enabled, otherwise perf-kmem will show wrong stats ifndef
CONFIG_KMEM_TRACE, because a kmalloc() memory allocation may
be traced by both trace_kmalloc() and trace_kmem_cache_alloc().
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Reviewed-by: NPekka Enberg <penberg@cs.helsinki.fi>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: linux-mm@kvack.org <linux-mm@kvack.org>
Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
LKML-Reference: <4B21F89A.7000801@cn.fujitsu.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

If the minalign is 64 bytes, then the 96 byte cache should not be created
because it would conflict with the 128 byte cache.

If the minalign is 256 bytes, patching the size_index table should not
result in a buffer overrun.

The calculation "(i - 1) / 8" used to access size_index[] is moved to
a separate function as suggested by Christoph Lameter.
Acked-by: NChristoph Lameter <cl@linux-foundation.org>
Signed-off-by: NAaro Koskinen <aaro.koskinen@nokia.com>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

kmem_cache_init_late() has been declared in slab.h

CC: Nick Piggin <npiggin@suse.de>
CC: Matt Mackall <mpm@selenic.com>
CC: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: NWu Fengguang <fengguang.wu@intel.com>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

The kmalloc_large() and kmalloc_large_node() functions were missed when
adding the kmemleak hooks to the slub allocator. However, they should be
traced to avoid false positives.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Acked-by: NPekka Enberg <penberg@cs.helsinki.fi>

As explained by Benjamin Herrenschmidt:

  Oh and btw, your patch alone doesn't fix powerpc, because it's missing
  a whole bunch of GFP_KERNEL's in the arch code... You would have to
  grep the entire kernel for things that check slab_is_available() and
  even then you'll be missing some.

  For example, slab_is_available() didn't always exist, and so in the
  early days on powerpc, we used a mem_init_done global that is set form
  mem_init() (not perfect but works in practice). And we still have code
  using that to do the test.

Therefore, mask out __GFP_WAIT, __GFP_IO, and __GFP_FS in the slab allocators
in early boot code to avoid enabling interrupts.
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

Impact: refactor code for future changes

Current kmemtrace.h is used both as header file of kmemtrace and kmem's
tracepoints definition.

Tracepoints' definition file may be used by other code, and should only have
definition of tracepoint.

We can separate include/trace/kmemtrace.h into 2 files:

  include/linux/kmemtrace.h: header file for kmemtrace
  include/trace/kmem.h:      definition of kmem tracepoints
Signed-off-by: NZhao Lei <zhaolei@cn.fujitsu.com>
Acked-by: NEduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Acked-by: NPekka Enberg <penberg@cs.helsinki.fi>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <49DEE68A.5040902@cn.fujitsu.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>