kmem_cache_destroy() should call rcu_barrier() *after* kmem_cache_close() and
*before* sysfs_slab_remove() or risk rcu_free_slab() being called after
kmem_cache is deleted (kfreed).

rmmod nf_conntrack can crash the machine because it has to kmem_cache_destroy()
a SLAB_DESTROY_BY_RCU enabled cache.

Cc: <stable@kernel.org>
Reported-by: NZdenek Kabelac <zdenek.kabelac@gmail.com>
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Acked-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.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>

Jesper noted that kmem_cache_destroy() invokes synchronize_rcu() rather than
rcu_barrier() in the SLAB_DESTROY_BY_RCU case, which could result in RCU
callbacks accessing a kmem_cache after it had been destroyed.

Cc: <stable@kernel.org>
Acked-by: NMatt Mackall <mpm@selenic.com>
Reported-by: NJesper Dangaard Brouer <hawk@comx.dk>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

SLUB uses higher order allocations by default but falls back to small
orders under memory pressure. Make sure the GFP mask used in the initial
allocation doesn't include __GFP_NOFAIL.
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The page allocator also needs the masking of gfp flags during boot,
so this moves it out of slab/slub and uses it with the page allocator
as well.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: NPekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

num_online_nodes() is called in a number of places but most often by the
page allocator when deciding whether the zonelist needs to be filtered
based on cpusets or the zonelist cache.  This is actually a heavy function
and touches a number of cache lines.

This patch stores the number of online nodes at boot time and updates the
value when nodes get onlined and offlined.  The value is then used in a
number of important paths in place of num_online_nodes().

[rientjes@google.com: do not override definition of node_set_online() with macro]
Signed-off-by: NChristoph Lameter <cl@linux-foundation.org>
Signed-off-by: NMel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This adds support for tracking the initializedness of memory that
was allocated with the page allocator. Highmem requests are not
tracked.

Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Acked-by: NPekka Enberg <penberg@cs.helsinki.fi>

[build fix for !CONFIG_KMEMCHECK]
Signed-off-by: NIngo Molnar <mingo@elte.hu>

[rebased for mainline inclusion]
Signed-off-by: NVegard Nossum <vegard.nossum@gmail.com>

Recent change to use slab allocations earlier exposed a bug where
SLUB can call schedule_work and try to call sysfs before it is
safe to do so.
Reported-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Tested-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NNick Piggin <npiggin@suse.de>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

Parts of this patch were contributed by Pekka Enberg but merged for
atomicity.

Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: NVegard Nossum <vegardno@ifi.uio.no>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

[rebased for mainline inclusion]
Signed-off-by: NVegard Nossum <vegardno@ifi.uio.no>

We must check for __GFP_NOFAIL like the page allocator does; otherwise we end
up with false positives. While at it, add the printk_ratelimit() check in SLUB
as well.

Cc: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

Fix this build error when CONFIG_SLUB_DEBUG is not set:
mm/slub.c: In function 'slab_out_of_memory':
mm/slub.c:1551: error: 'struct kmem_cache_node' has no member named 'nr_slabs'
mm/slub.c:1552: error: 'struct kmem_cache_node' has no member named 'total_objects'

[ penberg@cs.helsinki.fi: cleanups ]
Signed-off-by: NAlexander Beregalov <a.beregalov@gmail.com>
Signed-off-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>

This patch makes kmalloc() available earlier in the boot sequence so we can get
rid of some bootmem allocations. The bulk of the changes are due to
kmem_cache_init() being called with interrupts disabled which requires some
changes to allocator boostrap code.

Note: 32-bit x86 does WP protect test in mem_init() so we must setup traps
before we call mem_init() during boot as reported by Ingo Molnar:

  We have a hard crash in the WP-protect code:

  [    0.000000] Checking if this processor honours the WP bit even in supervisor mode...BUG: Int 14: CR2 ffcff000
  [    0.000000]      EDI 00000188  ESI 00000ac7  EBP c17eaf9c  ESP c17eaf8c
  [    0.000000]      EBX 000014e0  EDX 0000000e  ECX 01856067  EAX 00000001
  [    0.000000]      err 00000003  EIP c10135b1   CS 00000060  flg 00010002
  [    0.000000] Stack: c17eafa8 c17fd410 c16747bc c17eafc4 c17fd7e5 000011fd f8616000 c18237cc
  [    0.000000]        00099800 c17bb000 c17eafec c17f1668 000001c5 c17f1322 c166e039 c1822bf0
  [    0.000000]        c166e033 c153a014 c18237cc 00020800 c17eaff8 c17f106a 00020800 01ba5003
  [    0.000000] Pid: 0, comm: swapper Not tainted 2.6.30-tip-02161-g7a74539-dirty #52203
  [    0.000000] Call Trace:
  [    0.000000]  [<c15357c2>] ? printk+0x14/0x16
  [    0.000000]  [<c10135b1>] ? do_test_wp_bit+0x19/0x23
  [    0.000000]  [<c17fd410>] ? test_wp_bit+0x26/0x64
  [    0.000000]  [<c17fd7e5>] ? mem_init+0x1ba/0x1d8
  [    0.000000]  [<c17f1668>] ? start_kernel+0x164/0x2f7
  [    0.000000]  [<c17f1322>] ? unknown_bootoption+0x0/0x19c
  [    0.000000]  [<c17f106a>] ? __init_begin+0x6a/0x6f
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by Linus Torvalds <torvalds@linux-foundation.org>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

This patch adds the callbacks to kmemleak_(alloc|free) functions from the
slub allocator.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: NPekka Enberg <penberg@cs.helsinki.fi>

As suggested by Mel Gorman, add out-of-memory diagnostics to the SLUB allocator
to make debugging OOM conditions easier. This patch helped hunt down a nasty
OOM issue that popped up every now that was caused by SLUB debugging code which
forced 4096 byte allocations to use order 1 pages even in the fallback case.

An example print out looks like this:

  <snip page allocator out-of-memory message>
  SLUB: Unable to allocate memory on node -1 (gfp=20)
    cache: kmalloc-4096, object size: 4096, buffer size: 4168, default order: 3, min order: 1
    node 0: slabs: 95, objs: 665, free: 0
Acked-by: NChristoph Lameter <cl@linux-foundation.org>
Acked-by: NMel Gorman <mel@csn.ul.ie>
Tested-by: NLarry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

SLUB does not correctly account reclaim_state.reclaimed_slab, so it will
break memory reclaim. Account it like SLAB does.

Cc: stable@kernel.org
Cc: linux-mm@kvack.org
Cc: Matt Mackall <mpm@selenic.com>
Acked-by: NChristoph Lameter <cl@linux-foundation.org>
Signed-off-by: NNick Piggin <npiggin@suse.de>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

slub_max_order may not be equal to or greater than MAX_ORDER.

Additionally, if a single object cannot be placed in a slab of
slub_max_order, it still must allocate slabs below MAX_ORDER.
Acked-by: NChristoph Lameter <cl@linux-foundation.org>
Signed-off-by: NDavid Rientjes <rientjes@google.com>
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>

Impact: also output kfree(NULL) entries

This patch moves the trace_kfree() calls before the ZERO_OR_NULL_PTR
check so that we can trace call-sites that call kfree() with NULL many
times which might be an indication of a bug.
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
LKML-Reference: <1237971957.30175.18.camel@penberg-laptop>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

kmemtrace now uses tracepoints instead of markers. We no longer need to
use format specifiers to pass arguments.
Signed-off-by: NEduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
[ folded: Use the new TP_PROTO and TP_ARGS to fix the build.     ]
[ folded: fix build when CONFIG_KMEMTRACE is disabled.           ]
[ folded: define tracepoints when CONFIG_TRACEPOINTS is enabled. ]
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
LKML-Reference: <ae61c0f37156db8ec8dc0d5778018edde60a92e3.1237813499.git.eduard.munteanu@linux360.ro>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Use get_track() in set_track()
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

As suggested by Christoph Lameter, rename calculate_min_partial() to
set_min_partial() as the function doesn't really do any calculations.

Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

Now that a cache's min_partial has been moved to struct kmem_cache, it's
possible to easily tune it from userspace by adding a sysfs attribute.

It may not be desirable to keep a large number of partial slabs around
if a cache is used infrequently and memory, especially when constrained
by a cgroup, is scarce.  It's better to allow userspace to set the
minimum policy per cache instead of relying explicitly on
kmem_cache_shrink().

The memory savings from simply moving min_partial from struct
kmem_cache_node to struct kmem_cache is obviously not significant
(unless maybe you're from SGI or something), at the largest it's

	# allocated caches * (MAX_NUMNODES - 1) * sizeof(unsigned long)

The true savings occurs when userspace reduces the number of partial
slabs that would otherwise be wasted, especially on machines with a
large number of nodes (ia64 with CONFIG_NODES_SHIFT at 10 for default?).
As well as the kernel estimates ideal values for n->min_partial and
ensures it's within a sane range, userspace has no other input other
than writing to /sys/kernel/slab/cache/shrink.

There simply isn't any better heuristic to add when calculating the
partial values for a better estimate that works for all possible caches.
And since it's currently a static value, the user really has no way of
reclaiming that wasted space, which can be significant when constrained
by a cgroup (either cpusets or, later, memory controller slab limits)
without shrinking it entirely.

This also allows the user to specify that increased fragmentation and
more partial slabs are actually desired to avoid the cost of allocating
new slabs at runtime for specific caches.

There's also no reason why this should be a per-struct kmem_cache_node
value in the first place.  You could argue that a machine would have
such node size asymmetries that it should be specified on a per-node
basis, but we know nobody is doing that right now since it's a purely
static value at the moment and there's no convenient way to tune that
via slub's sysfs interface.

Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

Although it allows for better cacheline use, it is unnecessary to save a
copy of the cache's min_partial value in each kmem_cache_node.

Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

As a preparational patch to bump up page allocator pass-through threshold,
introduce two new constants SLUB_MAX_SIZE and SLUB_PAGE_SHIFT and convert
mm/slub.c to use them.
Reported-by: N"Zhang, Yanmin" <yanmin_zhang@linux.intel.com>
Tested-by: N"Zhang, Yanmin" <yanmin_zhang@linux.intel.com>
Signed-off-by: NChristoph Lameter <cl@linux-foundation.org>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

The default order of kmalloc-8192 on 2*4 stoakley is an issue of
calculate_order.

slab_size       order           name
-------------------------------------------------
4096            3               sgpool-128
8192            2               kmalloc-8192
16384           3               kmalloc-16384

kmalloc-8192's default order is smaller than sgpool-128's.

On 4*4 tigerton machine, a similiar issue appears on another kmem_cache.

Function calculate_order uses 'min_objects /= 2;' to shrink. Plus size
calculation/checking in slab_order, sometimes above issue appear.

Below patch against 2.6.29-rc2 fixes it.

I checked the default orders of all kmem_cache and they don't become
smaller than before. So the patch wouldn't hurt performance.

Signed-off-by Zhang Yanmin <yanmin.zhang@linux.intel.com>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

As a preparational patch to bump up page allocator pass-through threshold,
introduce two new constants SLUB_MAX_SIZE and SLUB_PAGE_SHIFT and convert
mm/slub.c to use them.
Reported-by: N"Zhang, Yanmin" <yanmin_zhang@linux.intel.com>
Tested-by: N"Zhang, Yanmin" <yanmin_zhang@linux.intel.com>
Signed-off-by: NChristoph Lameter <cl@linux-foundation.org>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

Here is another version, with the incremental patch rolled up, and
added reclaim context annotation to kswapd, and allocation tracing
to slab allocators (which may only ever reach the page allocator
in rare cases, so it is good to put annotations here too).

Haven't tested this version as such, but it should be getting closer
to merge worthy ;)

--
After noticing some code in mm/filemap.c accidentally perform a __GFP_FS
allocation when it should not have been, I thought it might be a good idea to
try to catch this kind of thing with lockdep.

I coded up a little idea that seems to work. Unfortunately the system has to
actually be in __GFP_FS page reclaim, then take the lock, before it will mark
it. But at least that might still be some orders of magnitude more common
(and more debuggable) than an actual deadlock condition, so we have some
improvement I hope (the concept is no less complete than discovery of a lock's
interrupt contexts).

I guess we could even do the same thing with __GFP_IO (normal reclaim), and
even GFP_NOIO locks too... but filesystems will have the most locks and fiddly
code paths, so let's start there and see how it goes.

It *seems* to work. I did a quick test.

=================================
[ INFO: inconsistent lock state ]
2.6.28-rc6-00007-ged313489-dirty #26
---------------------------------
inconsistent {in-reclaim-W} -> {ov-reclaim-W} usage.
modprobe/8526 [HC0[0]:SC0[0]:HE1:SE1] takes:
 (testlock){--..}, at: [<ffffffffa0020055>] brd_init+0x55/0x216 [brd]
{in-reclaim-W} state was registered at:
  [<ffffffff80267bdb>] __lock_acquire+0x75b/0x1a60
  [<ffffffff80268f71>] lock_acquire+0x91/0xc0
  [<ffffffff8070f0e1>] mutex_lock_nested+0xb1/0x310
  [<ffffffffa002002b>] brd_init+0x2b/0x216 [brd]
  [<ffffffff8020903b>] _stext+0x3b/0x170
  [<ffffffff80272ebf>] sys_init_module+0xaf/0x1e0
  [<ffffffff8020c3fb>] system_call_fastpath+0x16/0x1b
  [<ffffffffffffffff>] 0xffffffffffffffff
irq event stamp: 3929
hardirqs last  enabled at (3929): [<ffffffff8070f2b5>] mutex_lock_nested+0x285/0x310
hardirqs last disabled at (3928): [<ffffffff8070f089>] mutex_lock_nested+0x59/0x310
softirqs last  enabled at (3732): [<ffffffff8061f623>] sk_filter+0x83/0xe0
softirqs last disabled at (3730): [<ffffffff8061f5b6>] sk_filter+0x16/0xe0

other info that might help us debug this:
1 lock held by modprobe/8526:
 #0:  (testlock){--..}, at: [<ffffffffa0020055>] brd_init+0x55/0x216 [brd]

stack backtrace:
Pid: 8526, comm: modprobe Not tainted 2.6.28-rc6-00007-ged313489-dirty #26
Call Trace:
 [<ffffffff80265483>] print_usage_bug+0x193/0x1d0
 [<ffffffff80266530>] mark_lock+0xaf0/0xca0
 [<ffffffff80266735>] mark_held_locks+0x55/0xc0
 [<ffffffffa0020000>] ? brd_init+0x0/0x216 [brd]
 [<ffffffff802667ca>] trace_reclaim_fs+0x2a/0x60
 [<ffffffff80285005>] __alloc_pages_internal+0x475/0x580
 [<ffffffff8070f29e>] ? mutex_lock_nested+0x26e/0x310
 [<ffffffffa0020000>] ? brd_init+0x0/0x216 [brd]
 [<ffffffffa002006a>] brd_init+0x6a/0x216 [brd]
 [<ffffffffa0020000>] ? brd_init+0x0/0x216 [brd]
 [<ffffffff8020903b>] _stext+0x3b/0x170
 [<ffffffff8070f8b9>] ? mutex_unlock+0x9/0x10
 [<ffffffff8070f83d>] ? __mutex_unlock_slowpath+0x10d/0x180
 [<ffffffff802669ec>] ? trace_hardirqs_on_caller+0x12c/0x190
 [<ffffffff80272ebf>] sys_init_module+0xaf/0x1e0
 [<ffffffff8020c3fb>] system_call_fastpath+0x16/0x1b
Signed-off-by: NNick Piggin <npiggin@suse.de>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Commit 7b2cd92a ("crypto: api - Fix
zeroing on free") added modular user of ksize(). Export that to fix
crypto.ko compilation.

Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NKirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

The per cpu array of kmem_cache_cpu structures accomodates
NR_KMEM_CACHE_CPU such structs.

When this array overflows and a struct is allocated by kmalloc(), it may
have an address at the upper bound of this array.  If this happens, it
does not get freed and the per cpu kmem_cache_cpu_free pointer will be out
of bounds after kmem_cache_destroy() or cpu offlining.

Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

There's no reason to use ->objsize from struct kmem_cache in slab_free() for
the SLAB_DEBUG_OBJECTS case. All it does is generate extra cache pressure as we
try very hard not to touch struct kmem_cache in the fast-path.
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

It is always "an" if there is a vowel _spoken_ (not written).
So it is:
"an hour" (spoken vowel)
but
"a uniform" (spoken 'j')
Signed-off-by: NFrederik Schwarzer <schwarzerf@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Impact: Use new API

Convert kernel mm functions to use struct cpumask.

We skip include/linux/percpu.h and mm/allocpercpu.c, which are in flux.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NMike Travis <travis@sgi.com>
Reviewed-by: NChristoph Lameter <cl@linux-foundation.org>

Impact: new tracer plugin

This patch adapts kmemtrace raw events tracing to the unified tracing API.

To enable and use this tracer, just do the following:

 echo kmemtrace > /debugfs/tracing/current_tracer
 cat /debugfs/tracing/trace

You will have the following output:

 # tracer: kmemtrace
 #
 #
 # ALLOC  TYPE  REQ   GIVEN  FLAGS           POINTER         NODE    CALLER
 # FREE   |      |     |       |              |   |            |        |
 # |

type_id 1 call_site 18446744071565527833 ptr 18446612134395152256
type_id 0 call_site 18446744071565585597 ptr 18446612134405955584 bytes_req 4096 bytes_alloc 4096 gfp_flags 208 node -1
type_id 1 call_site 18446744071565585534 ptr 18446612134405955584
type_id 0 call_site 18446744071565585597 ptr 18446612134405955584 bytes_req 4096 bytes_alloc 4096 gfp_flags 208 node -1
type_id 0 call_site 18446744071565636711 ptr 18446612134345164672 bytes_req 240 bytes_alloc 240 gfp_flags 208 node -1
type_id 1 call_site 18446744071565585534 ptr 18446612134405955584
type_id 0 call_site 18446744071565585597 ptr 18446612134405955584 bytes_req 4096 bytes_alloc 4096 gfp_flags 208 node -1
type_id 0 call_site 18446744071565636711 ptr 18446612134345164912 bytes_req 240 bytes_alloc 240 gfp_flags 208 node -1
type_id 1 call_site 18446744071565585534 ptr 18446612134405955584
type_id 0 call_site 18446744071565585597 ptr 18446612134405955584 bytes_req 4096 bytes_alloc 4096 gfp_flags 208 node -1
type_id 0 call_site 18446744071565636711 ptr 18446612134345165152 bytes_req 240 bytes_alloc 240 gfp_flags 208 node -1
type_id 0 call_site 18446744071566144042 ptr 18446612134346191680 bytes_req 1304 bytes_alloc 1312 gfp_flags 208 node -1
type_id 1 call_site 18446744071565585534 ptr 18446612134405955584
type_id 0 call_site 18446744071565585597 ptr 18446612134405955584 bytes_req 4096 bytes_alloc 4096 gfp_flags 208 node -1
type_id 1 call_site 18446744071565585534 ptr 18446612134405955584

That was to stay backward compatible with the format output produced in
inux/tracepoint.h.

This is the default ouput, but note that I tried something else.

If you change an option:

echo kmem_minimalistic > /debugfs/trace_options

and then cat /debugfs/trace, you will have the following output:

 # tracer: kmemtrace
 #
 #
 # ALLOC  TYPE  REQ   GIVEN  FLAGS           POINTER         NODE    CALLER
 # FREE   |      |     |       |              |   |            |        |
 # |

   -      C                            0xffff88007c088780          file_free_rcu
   +      K   4096   4096   000000d0   0xffff88007cad6000     -1   getname
   -      C                            0xffff88007cad6000          putname
   +      K   4096   4096   000000d0   0xffff88007cad6000     -1   getname
   +      K    240    240   000000d0   0xffff8800790dc780     -1   d_alloc
   -      C                            0xffff88007cad6000          putname
   +      K   4096   4096   000000d0   0xffff88007cad6000     -1   getname
   +      K    240    240   000000d0   0xffff8800790dc870     -1   d_alloc
   -      C                            0xffff88007cad6000          putname
   +      K   4096   4096   000000d0   0xffff88007cad6000     -1   getname
   +      K    240    240   000000d0   0xffff8800790dc960     -1   d_alloc
   +      K   1304   1312   000000d0   0xffff8800791d7340     -1   reiserfs_alloc_inode
   -      C                            0xffff88007cad6000          putname
   +      K   4096   4096   000000d0   0xffff88007cad6000     -1   getname
   -      C                            0xffff88007cad6000          putname
   +      K    992   1000   000000d0   0xffff880079045b58     -1   alloc_inode
   +      K    768   1024   000080d0   0xffff88007c096400     -1   alloc_pipe_info
   +      K    240    240   000000d0   0xffff8800790dca50     -1   d_alloc
   +      K    272    320   000080d0   0xffff88007c088780     -1   get_empty_filp
   +      K    272    320   000080d0   0xffff88007c088000     -1   get_empty_filp

Yeah I shall confess kmem_minimalistic should be: kmem_alternative.

Whatever, I find it more readable but this a personal opinion of course.
We can drop it if you want.

On the ALLOC/FREE column, + means an allocation and - a free.

On the type column, you have K = kmalloc, C = cache, P = page

I would like the flags to be GFP_* strings but that would not be easy to not
break the column with strings....

About the node...it seems to always be -1. I don't know why but that shouldn't
be difficult to find.

I moved linux/tracepoint.h to trace/tracepoint.h as well. I think that would
be more easy to find the tracer headers if they are all in their common
directory.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: avoid conflicts with kmemcheck

kmemcheck modifies the same area of slab.c and slub.c - move the
include lines up a bit.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Now that we use _RET_IP_ there's no need to cast 'caller' to unsigned long.
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

This patch adds kmemtrace hooks for __kmalloc_track_caller() and
__kmalloc_node_track_caller(). Currently, they set the call site pointer
to the value recieved as a parameter. (This could change if we implement
stack trace exporting in kmemtrace.)
Signed-off-by: NEduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

This adds hooks for the SLUB allocator, to allow tracing with kmemtrace.
Signed-off-by: NEduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

This patch replaces __builtin_return_address(0) with _RET_IP_, since a
previous patch moved _RET_IP_ and _THIS_IP_ to include/linux/kernel.h and
they're widely available now. This makes for shorter and easier to read
code.

[penberg@cs.helsinki.fi: remove _RET_IP_ casts to void pointer]
Signed-off-by: NEduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

If a slab cache is mergeable and the sysfs alias cannot be added, the
target cache shall have its refcount decremented.  kmem_cache_create()
will return NULL, so if kmem_cache_destroy() is ever called on the target
cache, it will never be freed if the refcount has been leaked.

Likewise, if a slab cache is not mergeable and the sysfs link cannot be
added, the new cache shall be removed from the slab_caches list.
kmem_cache_create() will return NULL, so it will be impossible to call
kmem_cache_destroy() on it.

Both of these operations require slub_lock since refcount of all slab
caches and slab_caches are protected by the lock.

In the mergeable case, it would be better to restore objsize and offset
back to their original values, but this could race with another merge
since slub_lock was dropped.

Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>