Commit Graph

559 Commits

Author SHA1 Message Date
Alex Shi 8028dcea8a slub: per cpu partial statistics change
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: Alex Shi <alex.shi@intel.com>
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2012-02-18 11:00:09 +02:00
Christoph Lameter 4de900b4d6 slub: include include for prefetch
Otherwise m68k breaks:

On Mon, 30 Jan 2012, Geert Uytterhoeven wrote:
> m68k/allmodconfig at http://kisskb.ellerman.id.au/kisskb/buildresult/5527349/
>
> mm/slub.c:274: error: implicit declaration of function 'prefetch'
>
> Sorry, didn't notice it earlier due to other build breakage in -next.

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2012-02-10 14:47:39 +02:00
Christoph Lameter 66c4c35c6b slub: Do not hold slub_lock when calling sysfs_slab_add()
sysfs_slab_add() calls various sysfs functions that actually may
end up in userspace doing all sorts of things.

Release the slub_lock after adding the kmem_cache structure to the list.
At that point the address of the kmem_cache is not known so we are
guaranteed exlusive access to the following modifications to the
kmem_cache structure.

If the sysfs_slab_add fails then reacquire the slub_lock to
remove the kmem_cache structure from the list.

Cc: <stable@vger.kernel.org>	# 3.3+
Reported-by: Sasha Levin <levinsasha928@gmail.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2012-02-06 12:24:13 +02:00
Eric Dumazet 0ad9500e16 slub: prefetch next freelist pointer in slab_alloc()
Recycling a page is a problem, since freelist link chain is hot on
cpu(s) which freed objects, and possibly very cold on cpu currently
owning slab.

Adding a prefetch of cache line containing the pointer to next object in
slab_alloc() helps a lot in many workloads, in particular on assymetric
ones (allocations done on one cpu, frees on another cpus). Added cost is
three machine instructions only.

Examples on my dual socket quad core ht machine (Intel CPU E5540
@2.53GHz) (16 logical cpus, 2 memory nodes), 64bit kernel.

Before patch :

# perf stat -r 32 hackbench 50 process 4000 >/dev/null

 Performance counter stats for 'hackbench 50 process 4000' (32 runs):

     327577,471718 task-clock                #   15,821 CPUs utilized            ( +-  0,64% )
        28 866 491 context-switches          #    0,088 M/sec                    ( +-  1,80% )
         1 506 929 CPU-migrations            #    0,005 M/sec                    ( +-  3,24% )
           127 151 page-faults               #    0,000 M/sec                    ( +-  0,16% )
   829 399 813 448 cycles                    #    2,532 GHz                      ( +-  0,64% )
   580 664 691 740 stalled-cycles-frontend   #   70,01% frontend cycles idle     ( +-  0,71% )
   197 431 700 448 stalled-cycles-backend    #   23,80% backend  cycles idle     ( +-  1,03% )
   503 548 648 975 instructions              #    0,61  insns per cycle
                                             #    1,15  stalled cycles per insn  ( +-  0,46% )
    95 780 068 471 branches                  #  292,389 M/sec                    ( +-  0,48% )
     1 426 407 916 branch-misses             #    1,49% of all branches          ( +-  1,35% )

      20,705679994 seconds time elapsed                                          ( +-  0,64% )

After patch :

# perf stat -r 32 hackbench 50 process 4000 >/dev/null

 Performance counter stats for 'hackbench 50 process 4000' (32 runs):

     286236,542804 task-clock                #   15,786 CPUs utilized            ( +-  1,32% )
        19 703 372 context-switches          #    0,069 M/sec                    ( +-  4,99% )
         1 658 249 CPU-migrations            #    0,006 M/sec                    ( +-  6,62% )
           126 776 page-faults               #    0,000 M/sec                    ( +-  0,12% )
   724 636 593 213 cycles                    #    2,532 GHz                      ( +-  1,32% )
   499 320 714 837 stalled-cycles-frontend   #   68,91% frontend cycles idle     ( +-  1,47% )
   156 555 126 809 stalled-cycles-backend    #   21,60% backend  cycles idle     ( +-  2,22% )
   463 897 792 661 instructions              #    0,64  insns per cycle
                                             #    1,08  stalled cycles per insn  ( +-  0,94% )
    87 717 352 563 branches                  #  306,451 M/sec                    ( +-  0,99% )
       941 738 280 branch-misses             #    1,07% of all branches          ( +-  3,35% )

      18,132070670 seconds time elapsed                                          ( +-  1,30% )

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Christoph Lameter <cl@linux.com>
CC: Matt Mackall <mpm@selenic.com>
CC: David Rientjes <rientjes@google.com>
CC: "Alex,Shi" <alex.shi@intel.com>
CC: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2012-01-24 21:53:57 +02:00
Heiko Carstens 2565409fc0 mm,x86,um: move CMPXCHG_DOUBLE config option
Move CMPXCHG_DOUBLE and rename it to HAVE_CMPXCHG_DOUBLE so architectures
can simply select the option if it is supported.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-12 20:13:03 -08:00
Heiko Carstens 43570fd2f4 mm,slub,x86: decouple size of struct page from CONFIG_CMPXCHG_LOCAL
While implementing cmpxchg_double() on s390 I realized that we don't set
CONFIG_CMPXCHG_LOCAL despite the fact that we have support for it.

However setting that option will increase the size of struct page by
eight bytes on 64 bit, which we certainly do not want.  Also, it doesn't
make sense that a present cpu feature should increase the size of struct
page.

Besides that it looks like the dependency to CMPXCHG_LOCAL is wrong and
that it should depend on CMPXCHG_DOUBLE instead.

This patch:

If an architecture supports CMPXCHG_LOCAL this shouldn't result
automatically in larger struct pages if the SLUB allocator is used.
Instead introduce a new config option "HAVE_ALIGNED_STRUCT_PAGE" which
can be selected if a double word aligned struct page is required.  Also
update x86 Kconfig so that it should work as before.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-12 20:13:03 -08:00
Linus Torvalds 6296e5d3c0 Merge branch 'slab/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux
* 'slab/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux:
  slub: disallow changing cpu_partial from userspace for debug caches
  slub: add missed accounting
  slub: Extract get_freelist from __slab_alloc
  slub: Switch per cpu partial page support off for debugging
  slub: fix a possible memleak in __slab_alloc()
  slub: fix slub_max_order Documentation
  slub: add missed accounting
  slab: add taint flag outputting to debug paths.
  slub: add taint flag outputting to debug paths
  slab: introduce slab_max_order kernel parameter
  slab: rename slab_break_gfp_order to slab_max_order
2012-01-11 18:52:23 -08:00
Pekka Enberg 5878cf431c Merge branch 'slab/urgent' into slab/for-linus 2012-01-11 21:11:29 +02:00
Stanislaw Gruszka fc8d8620d3 slub: min order when debug_guardpage_minorder > 0
Disable slub debug facilities and allocate slabs at minimal order when
debug_guardpage_minorder > 0 to increase probability to catch random
memory corruption by cpu exception.

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-10 16:30:43 -08:00
David Rientjes 74ee4ef1f9 slub: disallow changing cpu_partial from userspace for debug caches
For caches with debugging enabled, "slub: Switch per cpu partial page
support off for debugging" changes cpu_partial to 0.  It shouldn't be
tunable from userspace for such caches, otherwise the same accounting
issues arise during validation.

This patch disallows tuning /sys/kernel/slab/cache/cpu_partial to be non-
zero for caches with debugging enabled.

Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2012-01-10 21:31:09 +02:00
Linus Torvalds 6b3da11b3c Merge branch 'for-3.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
* 'for-3.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
  percpu: Remove irqsafe_cpu_xxx variants

Fix up conflict in arch/x86/include/asm/percpu.h due to clash with
cebef5beed ("x86: Fix and improve percpu_cmpxchg{8,16}b_double()")
which edited the (now removed) irqsafe_cpu_cmpxchg*_double code.
2012-01-09 13:08:28 -08:00
Jan Beulich cdcd629869 x86: Fix and improve cmpxchg_double{,_local}()
Just like the per-CPU ones they had several
problems/shortcomings:

Only the first memory operand was mentioned in the asm()
operands, and the 2x64-bit version didn't have a memory clobber
while the 2x32-bit one did. The former allowed the compiler to
not recognize the need to re-load the data in case it had it
cached in some register, while the latter was overly
destructive.

The types of the local copies of the old and new values were
incorrect (the types of the pointed-to variables should be used
here, to make sure the respective old/new variable types are
compatible).

The __dummy/__junk variables were pointless, given that local
copies of the inputs already existed (and can hence be used for
discarded outputs).

The 32-bit variant of cmpxchg_double_local() referenced
cmpxchg16b_local().

At once also:

 - change the return value type to what it really is: 'bool'
 - unify 32- and 64-bit variants
 - abstract out the common part of the 'normal' and 'local' variants

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/4F01F12A020000780006A19B@nat28.tlf.novell.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-01-04 15:01:54 +01:00
Christoph Lameter 933393f58f percpu: Remove irqsafe_cpu_xxx variants
We simply say that regular this_cpu use must be safe regardless of
preemption and interrupt state.  That has no material change for x86
and s390 implementations of this_cpu operations.  However, arches that
do not provide their own implementation for this_cpu operations will
now get code generated that disables interrupts instead of preemption.

-tj: This is part of on-going percpu API cleanup.  For detailed
     discussion of the subject, please refer to the following thread.

     http://thread.gmane.org/gmane.linux.kernel/1222078

Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
LKML-Reference: <alpine.DEB.2.00.1112221154380.11787@router.home>
2011-12-22 10:40:20 -08:00
Shaohua Li b13683d1cc slub: add missed accounting
With per-cpu partial list, slab is added to partial list first and then moved
to node list. The __slab_free() code path for add/remove_partial is almost
deprecated(except for slub debug). But we forget to account add/remove_partial
when move per-cpu partial pages to node list, so the statistics for such events
are always 0. Add corresponding accounting.

This is against the patch "slub: use correct parameter to add a page to
partial list tail"

Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-12-13 22:27:09 +02:00
Christoph Lameter 213eeb9fd9 slub: Extract get_freelist from __slab_alloc
get_freelist retrieves free objects from the page freelist (put there by remote
frees) or deactivates a slab page if no more objects are available.

Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-12-13 22:17:10 +02:00
Christoph Lameter 8f1e33daed slub: Switch per cpu partial page support off for debugging
Eric saw an issue with accounting of slabs during validation. Its not
possible to determine accurately how many per cpu partial slabs exist at
any time so this switches off per cpu partial pages during debug.

Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-12-13 22:14:02 +02:00
Eric Dumazet 73736e0387 slub: fix a possible memleak in __slab_alloc()
Zhihua Che reported a possible memleak in slub allocator on
CONFIG_PREEMPT=y builds.

It is possible current thread migrates right before disabling irqs in
__slab_alloc(). We must check again c->freelist, and perform a normal
allocation instead of scratching c->freelist.

Many thanks to Zhihua Che for spotting this bug, introduced in 2.6.39

V2: Its also possible an IRQ freed one (or several) object(s) and
populated c->freelist, so its not a CONFIG_PREEMPT only problem.

Cc: <stable@vger.kernel.org>        [2.6.39+]
Reported-by: Zhihua Che <zhihua.che@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-12-13 22:11:21 +02:00
Shaohua Li 4c493a5a5c slub: add missed accounting
With per-cpu partial list, slab is added to partial list first and then moved
to node list. The __slab_free() code path for add/remove_partial is almost
deprecated(except for slub debug). But we forget to account add/remove_partial
when move per-cpu partial pages to node list, so the statistics for such events
are always 0. Add corresponding accounting.

This is against the patch "slub: use correct parameter to add a page to
partial list tail"

Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-11-27 22:08:15 +02:00
Pekka Enberg 42616cacf8 Merge branch 'slab/urgent' into slab/next 2011-11-27 22:08:03 +02:00
Eric Dumazet bc6697d8a5 slub: avoid potential NULL dereference or corruption
show_slab_objects() can trigger NULL dereferences or memory corruption.

Another cpu can change its c->page to NULL or c->node to NUMA_NO_NODE
while we use them.

Use ACCESS_ONCE(c->page) and ACCESS_ONCE(c->node) to make sure this
cannot happen.

Acked-by: Christoph Lameter <cl@linux.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-11-24 08:44:19 +02:00
Christoph Lameter 42d623a8cd slub: use irqsafe_cpu_cmpxchg for put_cpu_partial
The cmpxchg must be irq safe. The fallback for this_cpu_cmpxchg only
disables preemption which results in per cpu partial page operation
potentially failing on non x86 platforms.

This patch fixes the following problem reported by Christian Kujau:

  I seem to hit it with heavy disk & cpu IO is in progress on this
  PowerBook
  G4. Full dmesg & .config: http://nerdbynature.de/bits/3.2.0-rc1/oops/

  I've enabled some debug options and now it really points to slub.c:2166

    http://nerdbynature.de/bits/3.2.0-rc1/oops/oops4m.jpg

  With debug options enabled I'm currently in the xmon debugger, not sure
  what to make of it yet, I'll try to get something useful out of it :)

Reported-by: Christian Kujau <lists@nerdbynature.de>
Tested-by: Christian Kujau <lists@nerdbynature.de>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-11-24 08:44:14 +02:00
Dave Jones 265d47e711 slub: add taint flag outputting to debug paths
When we get corruption reports, it's useful to see if the kernel was
tainted, to rule out problems we can't do anything about.

Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-11-16 21:14:40 +02:00
Shaohua Li 9ada19342b slub: move discard_slab out of node lock
Lockdep reports there is potential deadlock for slub node list_lock.
discard_slab() is called with the lock hold in unfreeze_partials(),
which could trigger a slab allocation, which could hold the lock again.

discard_slab() doesn't need hold the lock actually, if the slab is
already removed from partial list.

Acked-by: Christoph Lameter <cl@linux.com>
Reported-and-tested-by: Yong Zhang <yong.zhang0@gmail.com>
Reported-and-tested-by: Julie Sullivan <kernelmail.jms@gmail.com>
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-11-15 20:41:00 +02:00
Shaohua Li f64ae042d9 slub: use correct parameter to add a page to partial list tail
unfreeze_partials() needs add the page to partial list tail, since such page
hasn't too many free objects. We now explictly use DEACTIVATE_TO_TAIL for this,
while DEACTIVATE_TO_TAIL != 1. This will cause performance regression (eg, more
lock contention in node->list_lock) without below fix.

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Acked-by: Christoph Lameter <cl@linux.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-11-15 20:37:15 +02:00
Akinobu Mita 798248206b lib/string.c: introduce memchr_inv()
memchr_inv() is mainly used to check whether the whole buffer is filled
with just a specified byte.

The function name and prototype are stolen from logfs and the
implementation is from SLUB.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: Matt Mackall <mpm@selenic.com>
Acked-by: Joern Engel <joern@logfs.org>
Cc: Marcin Slusarz <marcin.slusarz@gmail.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-31 17:30:47 -07:00
Pekka Enberg e182a345d4 Merge branches 'slab/next' and 'slub/partial' into slab/for-linus 2011-10-26 18:09:12 +03:00
Alex Shi dcc3be6a54 slub: Discard slab page when node partial > minimum partial number
Discarding slab should be done when node partial > min_partial.  Otherwise,
node partial slab may eat up all memory.

Signed-off-by: Alex Shi <alex.shi@intel.com>
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-09-27 23:03:31 +03:00
Alex Shi 9f26490412 slub: correct comments error for per cpu partial
Correct comment errors, that mistake cpu partial objects number as pages
number, may make reader misunderstand.

Signed-off-by: Alex Shi <alex.shi@intel.com>
Reviewed-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-09-27 23:03:30 +03:00
Vasiliy Kulikov ab067e99d2 mm: restrict access to slab files under procfs and sysfs
Historically /proc/slabinfo and files under /sys/kernel/slab/* have
world read permissions and are accessible to the world.  slabinfo
contains rather private information related both to the kernel and
userspace tasks.  Depending on the situation, it might reveal either
private information per se or information useful to make another
targeted attack.  Some examples of what can be learned by
reading/watching for /proc/slabinfo entries:

1) dentry (and different *inode*) number might reveal other processes fs
activity.  The number of dentry "active objects" doesn't strictly show
file count opened/touched by a process, however, there is a good
correlation between them.  The patch "proc: force dcache drop on
unauthorized access" relies on the privacy of dentry count.

2) different inode entries might reveal the same information as (1), but
these are more fine granted counters.  If a filesystem is mounted in a
private mount point (or even a private namespace) and fs type differs from
other mounted fs types, fs activity in this mount point/namespace is
revealed.  If there is a single ecryptfs mount point, the whole fs
activity of a single user is revealed.  Number of files in ecryptfs
mount point is a private information per se.

3) fuse_* reveals number of files / fs activity of a user in a user
private mount point.  It is approx. the same severity as ecryptfs
infoleak in (2).

4) sysfs_dir_cache similar to (2) reveals devices' addition/removal,
which can be otherwise hidden by "chmod 0700 /sys/".  With 0444 slabinfo
the precise number of sysfs files is known to the world.

5) buffer_head might reveal some kernel activity.  With other
information leaks an attacker might identify what specific kernel
routines generate buffer_head activity.

6) *kmalloc* infoleaks are very situational.  Attacker should watch for
the specific kmalloc size entry and filter the noise related to the unrelated
kernel activity.  If an attacker has relatively silent victim system, he
might get rather precise counters.

Additional information sources might significantly increase the slabinfo
infoleak benefits.  E.g. if an attacker knows that the processes
activity on the system is very low (only core daemons like syslog and
cron), he may run setxid binaries / trigger local daemon activity /
trigger network services activity / await sporadic cron jobs activity
/ etc. and get rather precise counters for fs and network activity of
these privileged tasks, which is unknown otherwise.

Also hiding slabinfo and /sys/kernel/slab/* is a one step to complicate
exploitation of kernel heap overflows (and possibly, other bugs).  The
related discussion:

http://thread.gmane.org/gmane.linux.kernel/1108378

To keep compatibility with old permission model where non-root
monitoring daemon could watch for kernel memleaks though slabinfo one
should do:

    groupadd slabinfo
    usermod -a -G slabinfo $MONITOR_USER

And add the following commands to init scripts (to mountall.conf in
Ubuntu's upstart case):

    chmod g+r /proc/slabinfo /sys/kernel/slab/*/*
    chgrp slabinfo /proc/slabinfo /sys/kernel/slab/*/*

Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Reviewed-by: Kees Cook <kees@ubuntu.com>
Reviewed-by: Dave Hansen <dave@linux.vnet.ibm.com>
Acked-by: Christoph Lameter <cl@gentwo.org>
Acked-by: David Rientjes <rientjes@google.com>
CC: Valdis.Kletnieks@vt.edu
CC: Linus Torvalds <torvalds@linux-foundation.org>
CC: Alan Cox <alan@linux.intel.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-09-27 22:59:27 +03:00
Pekka Enberg d20bbfab01 Merge branch 'slab/urgent' into slab/next 2011-09-19 17:46:07 +03:00
Alex,Shi 12d79634f8 slub: Code optimization in get_partial_node()
I find a way to reduce a variable in get_partial_node(). That is also helpful
for code understanding.

Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Alex Shi <alex.shi@intel.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-09-13 20:41:25 +03:00
Shaohua Li 136333d104 slub: explicitly document position of inserting slab to partial list
Adding slab to partial list head/tail is sensitive to performance.
So explicitly uses DEACTIVATE_TO_TAIL/DEACTIVATE_TO_HEAD to document
it to avoid we get it wrong.

Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Shaohua Li <shli@kernel.org>
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-08-27 11:59:00 +03:00
Shaohua Li 130655ef09 slub: add slab with one free object to partial list tail
The slab has just one free object, adding it to partial list head doesn't make
sense. And it can cause lock contentation. For example,
1. CPU takes the slab from partial list
2. fetch an object
3. switch to another slab
4. free an object, then the slab is added to partial list again
In this way n->list_lock will be heavily contended.
In fact, Alex had a hackbench regression. 3.1-rc1 performance drops about 70%
against 3.0. This patch fixes it.

Acked-by: Christoph Lameter <cl@linux.com>
Reported-by: Alex Shi <alex.shi@intel.com>
Signed-off-by: Shaohua Li <shli@kernel.org>
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-08-27 11:58:59 +03:00
Christoph Lameter 49e2258586 slub: per cpu cache for partial pages
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: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-08-19 19:34:27 +03:00
Christoph Lameter 497b66f2ec slub: return object pointer from get_partial() / new_slab().
There is no need anymore to return the pointer to a slab page from get_partial()
since the page reference can be stored in the kmem_cache_cpu structures "page" field.

Return an object pointer instead.

That in turn allows a simplification of the spaghetti code in __slab_alloc().

Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-08-19 19:34:27 +03:00
Christoph Lameter acd19fd1a7 slub: pass kmem_cache_cpu pointer to get_partial()
Pass the kmem_cache_cpu pointer to get_partial(). That way
we can avoid the this_cpu_write() statements.

Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-08-19 19:34:26 +03:00
Christoph Lameter e6e82ea112 slub: Prepare inuse field in new_slab()
inuse will always be set to page->objects. There is no point in
initializing the field to zero in new_slab() and then overwriting
the value in __slab_alloc().

Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-08-19 19:34:26 +03:00
Christoph Lameter 7db0d70540 slub: Remove useless statements in __slab_alloc
Two statements in __slab_alloc() do not have any effect.

1. c->page is already set to NULL by deactivate_slab() called right before.

2. gfpflags are masked in new_slab() before being passed to the page
   allocator. There is no need to mask gfpflags in __slab_alloc in particular
   since most frequent processing in __slab_alloc does not require the use of a
   gfpmask.

Cc: torvalds@linux-foundation.org
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-08-19 19:34:25 +03:00
Christoph Lameter 69cb8e6b7c slub: free slabs without holding locks
There are two situations in which slub holds a lock while releasing
pages:

	A. During kmem_cache_shrink()
	B. During kmem_cache_close()

For A build a list while holding the lock and then release the pages
later. In case of B we are the last remaining user of the slab so
there is no need to take the listlock.

After this patch all calls to the page allocator to free pages are
done without holding any spinlocks. kmem_cache_destroy() will still
hold the slub_lock semaphore.

Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-08-19 19:34:25 +03:00
Christoph Lameter 81107188f1 slub: Fix partial count comparison confusion
deactivate_slab() has the comparison if more than the minimum number of
partial pages are in the partial list wrong. An effect of this may be that
empty pages are not freed from deactivate_slab(). The result could be an
OOM due to growth of the partial slabs per node. Frees mostly occur from
__slab_free which is okay so this would only affect use cases where a lot
of switching around of per cpu slabs occur.

Switching per cpu slabs occurs with high frequency if debugging options are
enabled.

Reported-and-tested-by: Xiaotian Feng <xtfeng@gmail.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-08-09 21:12:31 +03:00
Akinobu Mita ef62fb32b7 slub: fix check_bytes() for slub debugging
The check_bytes() function is used by slub debugging.  It returns a pointer
to the first unmatching byte for a character in the given memory area.

If the character for matching byte is greater than 0x80, check_bytes()
doesn't work.  Becuase 64-bit pattern is generated as below.

	value64 = value | value << 8 | value << 16 | value << 24;
	value64 = value64 | value64 << 32;

The integer promotions are performed and sign-extended as the type of value
is u8.  The upper 32 bits of value64 is 0xffffffff in the first line, and
the second line has no effect.

This fixes the 64-bit pattern generation.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Matt Mackall <mpm@selenic.com>
Reviewed-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-08-09 16:37:48 +03:00
Christoph Lameter 6fbabb20fa slub: Fix full list corruption if debugging is on
When a slab is freed by __slab_free() and the slab can only contain a
single object ever then it was full (and therefore not on the partial
lists but on the full list in the debug case) before we reached
slab_empty.

This caused the following full list corruption when SLUB debugging was enabled:

  [ 5913.233035] ------------[ cut here ]------------
  [ 5913.233097] WARNING: at lib/list_debug.c:53 __list_del_entry+0x8d/0x98()
  [ 5913.233101] Hardware name: Adamo 13
  [ 5913.233105] list_del corruption. prev->next should be ffffea000434fd20, but was ffffea0004199520
  [ 5913.233108] Modules linked in: nfs fscache fuse ebtable_nat ebtables ppdev parport_pc lp parport ipt_MASQUERADE iptable_nat nf_nat nfsd lockd nfs_acl auth_rpcgss xt_CHECKSUM sunrpc iptable_mangle bridge stp llc cpufreq_ondemand acpi_cpufreq freq_table mperf ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_filter ip6_tables rfcomm bnep arc4 iwlagn snd_hda_codec_hdmi snd_hda_codec_idt snd_hda_intel btusb mac80211 snd_hda_codec bluetooth snd_hwdep snd_seq snd_seq_device snd_pcm usb_debug dell_wmi sparse_keymap cdc_ether usbnet cdc_acm uvcvideo cdc_wdm mii cfg80211 snd_timer dell_laptop videodev dcdbas snd microcode v4l2_compat_ioctl32 soundcore joydev tg3 pcspkr snd_page_alloc iTCO_wdt i2c_i801 rfkill iTCO_vendor_support wmi virtio_net kvm_intel kvm ipv6 xts gf128mul dm_crypt i915 drm_kms_helper drm i2c_algo_bit i2c_core video [last unloaded: scsi_wait_scan]
  [ 5913.233213] Pid: 0, comm: swapper Not tainted 3.0.0+ #127
  [ 5913.233213] Call Trace:
  [ 5913.233213]  <IRQ>  [<ffffffff8105df18>] warn_slowpath_common+0x83/0x9b
  [ 5913.233213]  [<ffffffff8105dfd3>] warn_slowpath_fmt+0x46/0x48
  [ 5913.233213]  [<ffffffff8127e7c1>] __list_del_entry+0x8d/0x98
  [ 5913.233213]  [<ffffffff8127e7da>] list_del+0xe/0x2d
  [ 5913.233213]  [<ffffffff814e0430>] __slab_free+0x1db/0x235
  [ 5913.233213]  [<ffffffff811706ab>] ? bvec_free_bs+0x35/0x37
  [ 5913.233213]  [<ffffffff811706ab>] ? bvec_free_bs+0x35/0x37
  [ 5913.233213]  [<ffffffff811706ab>] ? bvec_free_bs+0x35/0x37
  [ 5913.233213]  [<ffffffff81133085>] kmem_cache_free+0x88/0x102
  [ 5913.233213]  [<ffffffff811706ab>] bvec_free_bs+0x35/0x37
  [ 5913.233213]  [<ffffffff811706e1>] bio_free+0x34/0x64
  [ 5913.233213]  [<ffffffff813dc390>] dm_bio_destructor+0x12/0x14
  [ 5913.233213]  [<ffffffff8116fef6>] bio_put+0x2b/0x2d
  [ 5913.233213]  [<ffffffff813dccab>] clone_endio+0x9e/0xb4
  [ 5913.233213]  [<ffffffff8116f7dd>] bio_endio+0x2d/0x2f
  [ 5913.233213]  [<ffffffffa00148da>] crypt_dec_pending+0x5c/0x8b [dm_crypt]
  [ 5913.233213]  [<ffffffffa00150a9>] crypt_endio+0x78/0x81 [dm_crypt]

[ Full discussion here: https://lkml.org/lkml/2011/8/4/375 ]

Make sure that we remove such a slab also from the full lists.

Reported-and-tested-by: Dave Jones <davej@redhat.com>
Reported-and-tested-by: Xiaotian Feng <xtfeng@gmail.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-08-09 16:36:02 +03:00
Sebastian Andrzej Siewior ffc79d2880 slub: use print_hex_dump
Less code and same functionality. The output would be:

| Object c7428000: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
| Object c7428010: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
| Object c7428020: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
| Object c7428030: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b a5              kkkkkkkkkkk.
| Redzone c742803c: bb bb bb bb                                      ....
| Padding c7428064: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a  ZZZZZZZZZZZZZZZZ
| Padding c7428074: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a              ZZZZZZZZZZZZ

Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-07-31 19:16:48 +03:00
Linus Torvalds c11abbbaa3 Merge branch 'slub/lockless' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6
* 'slub/lockless' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6: (21 commits)
  slub: When allocating a new slab also prep the first object
  slub: disable interrupts in cmpxchg_double_slab when falling back to pagelock
  Avoid duplicate _count variables in page_struct
  Revert "SLUB: Fix build breakage in linux/mm_types.h"
  SLUB: Fix build breakage in linux/mm_types.h
  slub: slabinfo update for cmpxchg handling
  slub: Not necessary to check for empty slab on load_freelist
  slub: fast release on full slab
  slub: Add statistics for the case that the current slab does not match the node
  slub: Get rid of the another_slab label
  slub: Avoid disabling interrupts in free slowpath
  slub: Disable interrupts in free_debug processing
  slub: Invert locking and avoid slab lock
  slub: Rework allocator fastpaths
  slub: Pass kmem_cache struct to lock and freeze slab
  slub: explicit list_lock taking
  slub: Add cmpxchg_double_slab()
  mm: Rearrange struct page
  slub: Move page->frozen handling near where the page->freelist handling occurs
  slub: Do not use frozen page flag but a bit in the page counters
  ...
2011-07-30 08:21:48 -10:00
Linus Torvalds d3ec4844d4 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (43 commits)
  fs: Merge split strings
  treewide: fix potentially dangerous trailing ';' in #defined values/expressions
  uwb: Fix misspelling of neighbourhood in comment
  net, netfilter: Remove redundant goto in ebt_ulog_packet
  trivial: don't touch files that are removed in the staging tree
  lib/vsprintf: replace link to Draft by final RFC number
  doc: Kconfig: `to be' -> `be'
  doc: Kconfig: Typo: square -> squared
  doc: Konfig: Documentation/power/{pm => apm-acpi}.txt
  drivers/net: static should be at beginning of declaration
  drivers/media: static should be at beginning of declaration
  drivers/i2c: static should be at beginning of declaration
  XTENSA: static should be at beginning of declaration
  SH: static should be at beginning of declaration
  MIPS: static should be at beginning of declaration
  ARM: static should be at beginning of declaration
  rcu: treewide: Do not use rcu_read_lock_held when calling rcu_dereference_check
  Update my e-mail address
  PCIe ASPM: forcedly -> forcibly
  gma500: push through device driver tree
  ...

Fix up trivial conflicts:
 - arch/arm/mach-ep93xx/dma-m2p.c (deleted)
 - drivers/gpio/gpio-ep93xx.c (renamed and context nearby)
 - drivers/net/r8169.c (just context changes)
2011-07-25 13:56:39 -07:00
Christoph Lameter 9e577e8b46 slub: When allocating a new slab also prep the first object
We need to branch to the debug code for the first object if we allocate
a new slab otherwise the first object will be marked wrongly as inactive.

Tested-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-07-25 20:58:19 +03:00
Linus Torvalds f99b7880cb Merge branch 'slab-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6
* 'slab-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6:
  slab: fix DEBUG_SLAB warning
  slab: shrink sizeof(struct kmem_cache)
  slab: fix DEBUG_SLAB build
  SLUB: Fix missing <linux/stacktrace.h> include
  slub: reduce overhead of slub_debug
  slub: Add method to verify memory is not freed
  slub: Enable backtrace for create/delete points
  slab allocators: Provide generic description of alignment defines
  slab, slub, slob: Unify alignment definition
  slob/lockdep: Fix gfp flags passed to lockdep
2011-07-22 12:44:30 -07:00
Phil Carmody 497888cf69 treewide: fix potentially dangerous trailing ';' in #defined values/expressions
All these are instances of
  #define NAME value;
or
  #define NAME(params_opt) value;

These of course fail to build when used in contexts like
  if(foo $OP NAME)
  while(bar $OP NAME)
and may silently generate the wrong code in contexts such as
  foo = NAME + 1;    /* foo = value; + 1; */
  bar = NAME - 1;    /* bar = value; - 1; */
  baz = NAME & quux; /* baz = value; & quux; */

Reported on comp.lang.c,
Message-ID: <ab0d55fe-25e5-482b-811e-c475aa6065c3@c29g2000yqd.googlegroups.com>
Initial analysis of the dangers provided by Keith Thompson in that thread.

There are many more instances of more complicated macros having unnecessary
trailing semicolons, but this pile seems to be all of the cases of simple
values suffering from the problem. (Thus things that are likely to be found
in one of the contexts above, more complicated ones aren't.)

Signed-off-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-07-21 14:10:00 +02:00
Christoph Lameter 1d07171c5e slub: disable interrupts in cmpxchg_double_slab when falling back to pagelock
Split cmpxchg_double_slab into two functions. One for the case where we know that
interrupts are disabled (and therefore the fallback does not need to disable
interrupts) and one for the other cases where fallback will also disable interrupts.

This fixes the issue that __slab_free called cmpxchg_double_slab in some scenarios
without disabling interrupts.

Tested-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-07-18 15:17:02 +03:00
Pekka Enberg bfa71457a0 SLUB: Fix missing <linux/stacktrace.h> include
This fixes the following build breakage commit d6543e3 ("slub: Enable backtrace
for create/delete points"):

  CC      mm/slub.o
mm/slub.c: In function ‘set_track’:
mm/slub.c:428: error: storage size of ‘trace’ isn’t known
mm/slub.c:435: error: implicit declaration of function ‘save_stack_trace’
mm/slub.c:428: warning: unused variable ‘trace’
make[1]: *** [mm/slub.o] Error 1
make: *** [mm/slub.o] Error 2

Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-07-07 22:47:01 +03:00
Marcin Slusarz c4089f98e9 slub: reduce overhead of slub_debug
slub checks for poison one byte by one, which is highly inefficient
and shows up frequently as a highest cpu-eater in perf top.

Joining reads gives nice speedup:

(Compiling some project with different options)
                                 make -j12    make clean
slub_debug disabled:             1m 27s       1.2 s
slub_debug enabled:              1m 46s       7.6 s
slub_debug enabled + this patch: 1m 33s       3.2 s

check_bytes still shows up high, but not always at the top.

Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Matt Mackall <mpm@selenic.com>
Cc: linux-mm@kvack.org
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-07-07 22:44:45 +03:00
Ben Greear d18a90dd85 slub: Add method to verify memory is not freed
This is for tracking down suspect memory usage.

Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-07-07 22:17:08 +03:00
Ben Greear d6543e3935 slub: Enable backtrace for create/delete points
This patch attempts to grab a backtrace for the creation
and deletion points of the slub object.  When a fault is
detected, we can then get a better idea of where the item
was deleted.

Example output from debugging some funky nfs/rpc behaviour:

=============================================================================
BUG kmalloc-64: Object is on free-list
-----------------------------------------------------------------------------

INFO: Allocated in rpcb_getport_async+0x39c/0x5a5 [sunrpc] age=381 cpu=3 pid=3750
       __slab_alloc+0x348/0x3ba
       kmem_cache_alloc_trace+0x67/0xe7
       rpcb_getport_async+0x39c/0x5a5 [sunrpc]
       call_bind+0x70/0x75 [sunrpc]
       __rpc_execute+0x78/0x24b [sunrpc]
       rpc_execute+0x3d/0x42 [sunrpc]
       rpc_run_task+0x79/0x81 [sunrpc]
       rpc_call_sync+0x3f/0x60 [sunrpc]
       rpc_ping+0x42/0x58 [sunrpc]
       rpc_create+0x4aa/0x527 [sunrpc]
       nfs_create_rpc_client+0xb1/0xf6 [nfs]
       nfs_init_client+0x3b/0x7d [nfs]
       nfs_get_client+0x453/0x5ab [nfs]
       nfs_create_server+0x10b/0x437 [nfs]
       nfs_fs_mount+0x4ca/0x708 [nfs]
       mount_fs+0x6b/0x152
INFO: Freed in rpcb_map_release+0x3f/0x44 [sunrpc] age=30 cpu=2 pid=29049
       __slab_free+0x57/0x150
       kfree+0x107/0x13a
       rpcb_map_release+0x3f/0x44 [sunrpc]
       rpc_release_calldata+0x12/0x14 [sunrpc]
       rpc_free_task+0x59/0x61 [sunrpc]
       rpc_final_put_task+0x82/0x8a [sunrpc]
       __rpc_execute+0x23c/0x24b [sunrpc]
       rpc_async_schedule+0x10/0x12 [sunrpc]
       process_one_work+0x230/0x41d
       worker_thread+0x133/0x217
       kthread+0x7d/0x85
       kernel_thread_helper+0x4/0x10
INFO: Slab 0xffffea00029aa470 objects=20 used=9 fp=0xffff8800be7830d8 flags=0x20000000004081
INFO: Object 0xffff8800be7830d8 @offset=4312 fp=0xffff8800be7827a8

Bytes b4 0xffff8800be7830c8:  87 a8 96 00 01 00 00 00 5a 5a 5a 5a 5a 5a 5a 5a .�......ZZZZZZZZ
 Object 0xffff8800be7830d8:  6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
 Object 0xffff8800be7830e8:  6b 6b 6b 6b 01 08 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkk..kkkkkkkkkk
 Object 0xffff8800be7830f8:  6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
 Object 0xffff8800be783108:  6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b a5 kkkkkkkkkkkkkkk�
 Redzone 0xffff8800be783118:  bb bb bb bb bb bb bb bb                         �������������
 Padding 0xffff8800be783258:  5a 5a 5a 5a 5a 5a 5a 5a                         ZZZZZZZZ
Pid: 29049, comm: kworker/2:2 Not tainted 3.0.0-rc4+ #8
Call Trace:
 [<ffffffff811055c3>] print_trailer+0x131/0x13a
 [<ffffffff81105601>] object_err+0x35/0x3e
 [<ffffffff8110746f>] verify_mem_not_deleted+0x7a/0xb7
 [<ffffffffa02851b5>] rpcb_getport_done+0x23/0x126 [sunrpc]
 [<ffffffffa027d0ba>] rpc_exit_task+0x3f/0x6d [sunrpc]
 [<ffffffffa027d4ab>] __rpc_execute+0x78/0x24b [sunrpc]
 [<ffffffffa027d6c0>] ? rpc_execute+0x42/0x42 [sunrpc]
 [<ffffffffa027d6d0>] rpc_async_schedule+0x10/0x12 [sunrpc]
 [<ffffffff810611b7>] process_one_work+0x230/0x41d
 [<ffffffff81061102>] ? process_one_work+0x17b/0x41d
 [<ffffffff81063613>] worker_thread+0x133/0x217
 [<ffffffff810634e0>] ? manage_workers+0x191/0x191
 [<ffffffff81066e10>] kthread+0x7d/0x85
 [<ffffffff81485924>] kernel_thread_helper+0x4/0x10
 [<ffffffff8147eb18>] ? retint_restore_args+0x13/0x13
 [<ffffffff81066d93>] ? __init_kthread_worker+0x56/0x56
 [<ffffffff81485920>] ? gs_change+0x13/0x13

Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-07-07 22:17:03 +03:00
Christoph Lameter 4eade540fc slub: Not necessary to check for empty slab on load_freelist
load_freelist is now only branched to only if there are objects available.
So no need to check the object variable for NULL.

Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-07-02 13:26:57 +03:00
Christoph Lameter 03e404af26 slub: fast release on full slab
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: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-07-02 13:26:57 +03:00
Christoph Lameter e36a2652d7 slub: Add statistics for the case that the current slab does not match the node
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: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-07-02 13:26:56 +03:00
Christoph Lameter fc59c05306 slub: Get rid of the another_slab label
We can avoid deactivate slab in special cases if we do the
deactivation of slabs in each code flow that leads to new_slab.

Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-07-02 13:26:56 +03:00
Christoph Lameter 80f08c191f slub: Avoid disabling interrupts in free slowpath
Disabling interrupts can be avoided now. However, list operation still require
disabling interrupts since allocations can occur from interrupt
contexts and there is no way to perform atomic list operations.

The acquition of the list_lock therefore has to disable interrupts as well.

Dropping interrupt handling significantly simplifies the slowpath.

Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-07-02 13:26:56 +03:00
Christoph Lameter 5c2e4bbbd6 slub: Disable interrupts in free_debug processing
We will be calling free_debug_processing with interrupts disabled
in some case when the later patches are applied. Some of the
functions called by free_debug_processing expect interrupts to be
off.

Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-07-02 13:26:55 +03:00
Christoph Lameter 881db7fb03 slub: Invert locking and avoid slab lock
Locking slabs is no longer necesary if the arch supports cmpxchg operations
and if no debuggin features are used on a slab. If the arch does not support
cmpxchg then we fallback to use the slab lock to do a cmpxchg like operation.

The patch also changes the lock order. Slab locks are subsumed to the node lock
now. With that approach slab_trylocking is no longer necessary.

Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-07-02 13:26:55 +03:00
Christoph Lameter 2cfb7455d2 slub: Rework allocator fastpaths
Rework the allocation paths so that updates of the page freelist, frozen state
and number of objects use cmpxchg_double_slab().

Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-07-02 13:26:54 +03:00
Christoph Lameter 61728d1efc slub: Pass kmem_cache struct to lock and freeze slab
We need more information about the slab for the cmpxchg implementation.

Signed-off-by: Christoph Lameter <cl@linux.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-07-02 13:26:54 +03:00
Christoph Lameter 5cc6eee8a8 slub: explicit list_lock taking
The allocator fastpath rework does change the usage of the list_lock.
Remove the list_lock processing from the functions that hide them from the
critical sections and move them into those critical sections.

This in turn simplifies the support functions (no __ variant needed anymore)
and simplifies the lock handling on bootstrap.

Inline add_partial since it becomes pretty simple.

Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-07-02 13:26:54 +03:00
Christoph Lameter b789ef518b slub: Add cmpxchg_double_slab()
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: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-07-02 13:26:53 +03:00
Christoph Lameter 8cb0a5068f slub: Move page->frozen handling near where the page->freelist handling occurs
This is necessary because the frozen bit has to be handled in the same cmpxchg_double
with the freelist and the counters.

Signed-off-by: Christoph Lameter <cl@linux.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-07-02 13:26:53 +03:00
Christoph Lameter 50d5c41cd1 slub: Do not use frozen page flag but a bit in the page counters
Do not use a page flag for the frozen bit. It needs to be part
of the state that is handled with cmpxchg_double(). So use a bit
in the counter struct in the page struct for that purpose.

Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-07-02 13:26:52 +03:00
Christoph Lameter 7e0528dadc slub: Push irq disable into allocate_slab()
Do the irq handling in allocate_slab() instead of __slab_alloc().

__slab_alloc() is already cluttered and allocate_slab() is already
fiddling around with gfp flags.

v6->v7:
	Only increment ORDER_FALLBACK if we get a page during fallback

Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-07-02 13:26:52 +03:00
Chris Metcalf d4d84fef6d slub: always align cpu_slab to honor cmpxchg_double requirement
On an architecture without CMPXCHG_LOCAL but with DEBUG_VM enabled,
the VM_BUG_ON() in __pcpu_double_call_return_bool() will cause an early
panic during boot unless we always align cpu_slab properly.

In principle we could remove the alignment-testing VM_BUG_ON() for
architectures that don't have CMPXCHG_LOCAL, but leaving it in means
that new code will tend not to break x86 even if it is introduced
on another platform, and it's low cost to require alignment.

Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-06-03 19:33:49 +03:00
Linus Torvalds 49a78d085f slub: remove no-longer used 'unlock_out' label
Commit a71ae47a2c ("slub: Fix double bit unlock in debug mode")
removed the only goto to this label, resulting in

  mm/slub.c: In function '__slab_alloc':
  mm/slub.c:1834: warning: label 'unlock_out' defined but not used

fixed trivially by the removal of the label itself too.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-25 18:06:54 -07:00
Christoph Lameter a71ae47a2c slub: Fix double bit unlock in debug mode
Commit 442b06bcea ("slub: Remove node check in slab_free") added a
call to deactivate_slab() in the debug case in __slab_alloc(), which
unlocks the current slab used for allocation.  Going to the label
'unlock_out' then does it again.

Also, in the debug case we do not need all the other processing that the
'unlock_out' path does.  We always fall back to the slow path in the
debug case.  So the tid update is useless.

Similarly, ALLOC_SLOWPATH would just be incremented for all allocations.
Also a pretty useless thing.

So simply restore irq flags and return the object.

Signed-off-by: Christoph Lameter <cl@linux.com>
Reported-and-bisected-by: James Morris <jmorris@namei.org>
Reported-by: Ingo Molnar <mingo@elte.hu>
Reported-by: Jens Axboe <jaxboe@fusionio.com>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-25 08:38:24 -07:00
Pekka Enberg bfb91fb650 Merge branch 'slab/next' into for-linus
Conflicts:
	mm/slub.c
2011-05-23 19:50:39 +03:00
Christoph Lameter 442b06bcea slub: Remove node check in slab_free
We can set the page pointing in the percpu structure to
NULL to have the same effect as setting c->node to NUMA_NO_NODE.

Gets rid of one check in slab_free() that was only used for
forcing the slab_free to the slowpath for debugging.

We still need to set c->node to NUMA_NO_NODE to force the
slab_alloc() fastpath to the slowpath in case of debugging.

Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-05-21 12:53:53 +03:00
David Rientjes bd07d87fd4 slub: avoid label inside conditional
Jumping to a label inside a conditional is considered poor style,
especially considering the current organization of __slab_alloc().

This removes the 'load_from_page' label and just duplicates the three
lines of code that it uses:

	c->node = page_to_nid(page);
	c->page = page;
	goto load_freelist;

since it's probably not worth making this a separate helper function.

Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-05-17 22:19:00 +03:00
Christoph Lameter 1393d9a185 slub: Make CONFIG_DEBUG_PAGE_ALLOC work with new fastpath
Fastpath can do a speculative access to a page that CONFIG_DEBUG_PAGE_ALLOC may have
marked as invalid to retrieve the pointer to the next free object.

Use probe_kernel_read in that case in order not to cause a page fault.

Cc: <stable@kernel.org> # 38.x
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-05-17 22:18:55 +03:00
Christoph Lameter 6332aa9d25 slub: Avoid warning for !CONFIG_SLUB_DEBUG
Move the #ifdef so that get_map is only defined if CONFIG_SLUB_DEBUG is defined.

Reported-by: David Rientjes <rientjes@google.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-05-17 22:16:08 +03:00
Christoph Lameter 1759415e63 slub: Remove CONFIG_CMPXCHG_LOCAL ifdeffery
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: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-05-07 20:25:38 +03:00
Thomas Gleixner 30106b8ce2 slub: Fix the lockless code on 32-bit platforms with no 64-bit cmpxchg
The SLUB allocator use of the cmpxchg_double logic was wrong: it
actually needs the irq-safe one.

That happens automatically when we use the native unlocked 'cmpxchg8b'
instruction, but when compiling the kernel for older x86 CPUs that do
not support that instruction, we fall back to the generic emulation
code.

And if you don't specify that you want the irq-safe version, the generic
code ends up just open-coding the cmpxchg8b equivalent without any
protection against interrupts or preemption.  Which definitely doesn't
work for SLUB.

This was reported by Werner Landgraf <w.landgraf@ru.ru>, who saw
instability with his distro-kernel that was compiled to support pretty
much everything under the sun.  Most big Linux distributions tend to
compile for PPro and later, and would never have noticed this problem.

This also fixes the prototypes for the irqsafe cmpxchg_double functions
to use 'bool' like they should.

[ Btw, that whole "generic code defaults to no protection" design just
  sounds stupid - if the code needs no protection, there is no reason to
  use "cmpxchg_double" to begin with.  So we should probably just remove
  the unprotected version entirely as pointless.   - Linus ]

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reported-and-tested-by: werner <w.landgraf@ru.ru>
Acked-and-tested-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1105041539050.3005@ionos
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-04 14:20:20 -07:00
Christoph Lameter 8dc16c6c04 slub: Move debug handlign in __slab_free
Its easier to read if its with the check for debugging flags.

Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-04-17 14:03:20 +03:00
Christoph Lameter dc1fb7f436 slub: Move node determination out of hotpath
If the node does not change then there is no need to recalculate
the node from the page struct. So move the node determination
into the places where we acquire a new slab page.

Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-04-17 14:03:20 +03:00
Christoph Lameter 01ad8a7bc2 slub: Eliminate repeated use of c->page through a new page variable
__slab_alloc is full of "c->page" repeats. Lets just use one local variable
named "page" for this. Also avoids the need to a have another variable
called "new".

Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-04-17 14:03:19 +03:00
Christoph Lameter 5f80b13ae4 slub: get_map() function to establish map of free objects in a slab
The bit map of free objects in a slab page is determined in various functions
if debugging is enabled.

Provide a common function for that purpose.

Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-04-17 14:03:19 +03:00
Christoph Lameter 33de04ec4c slub: Use NUMA_NO_NODE in get_partial
A -1 was leftover during the conversion.

Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-04-17 14:03:19 +03:00
Li Zefan 607bf324ab slub: Fix a typo in config name
There's no config named SLAB_DEBUG, and it should be a typo
of SLUB_DEBUG.

Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-04-12 22:27:27 +03:00
Lucas De Marchi 25985edced Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 11:26:23 -03:00
Christoph Lameter b8c4c96ed4 SLUB: Write to per cpu data when allocating it
It turns out that the cmpxchg16b emulation has to access vmalloced
percpu memory with interrupts disabled. If the memory has never
been touched before then the fault necessary to establish the
mapping will not to occur and the kernel will fail on boot.

Fix that by reusing the CONFIG_PREEMPT code that writes the
cpu number into a field on every cpu. Writing to the per cpu
area before causes the mapping to be established before we get
to a cmpxchg16b emulation.

Tested-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-03-24 21:53:07 +02:00
Thomas Gleixner f9b615de46 slub: Fix debugobjects with lockless fastpath
On Thu, 24 Mar 2011, Ingo Molnar wrote:
> RIP: 0010:[<ffffffff810570a9>]  [<ffffffff810570a9>] get_next_timer_interrupt+0x119/0x260

That's a typical timer crash, but you were unable to debug it with
debugobjects because commit d3f661d6 broke those.

Cc: Christoph Lameter <cl@linux.com>
Tested-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-03-24 21:26:46 +02:00
Christoph Lameter 4fdccdfbb4 slub: Add statistics for this_cmpxchg_double failures
Add some statistics for debugging.

Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-03-22 20:48:04 +02:00
Christoph Lameter 2fd66c517d slub: Add missing irq restore for the OOM path
OOM path is missing the irq restore in the CONFIG_CMPXCHG_LOCAL case.

Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-03-22 20:48:04 +02:00
Pekka Enberg e8c500c2b6 Merge branch 'slub/lockless' into for-linus
Conflicts:
	include/linux/slub_def.h
2011-03-20 18:13:26 +02:00
Christoph Lameter a24c5a0ea9 slub: Dont define useless label in the !CONFIG_CMPXCHG_LOCAL case
The redo label needs #ifdeffery. Fixes the following problem introduced by
commit 8a5ec0ba42 ("Lockless (and preemptless) fastpaths for slub"):

  mm/slub.c: In function 'slab_free':
  mm/slub.c:2124: warning: label 'redo' defined but not used

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-03-20 18:11:07 +02:00
Pekka Enberg c914955675 Merge branch 'slab/rcu' into slab/next
Conflicts:
	mm/slub.c
2011-03-11 18:10:45 +02:00
Lai Jiangshan da9a638c6f slub,rcu: don't assume the size of struct rcu_head
The size of struct rcu_head may be changed. When it becomes larger,
it will pollute the page array.

We reserve some some bytes for struct rcu_head when a slab
is allocated in this situation.

Changed from V1:
	use VM_BUG_ON instead BUG_ON

Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-03-11 18:06:34 +02:00
Lai Jiangshan ab9a0f196f slub: automatically reserve bytes at the end of slab
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: Christoph Lameter <cl@linux.com>
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-03-11 18:06:34 +02:00
Christoph Lameter 8a5ec0ba42 Lockless (and preemptless) fastpaths for slub
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: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-03-11 17:42:49 +02:00
Christoph Lameter d3f661d69a slub: Get rid of slab_free_hook_irq()
The following patch will make the fastpaths lockless and will no longer
require interrupts to be disabled. Calling the free hook with irq disabled
will no longer be possible.

Move the slab_free_hook_irq() logic into slab_free_hook. Only disable
interrupts if the features are selected that require callbacks with
interrupts off and reenable after calls have been made.

Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-03-11 17:42:49 +02:00
Mariusz Kozlowski d71f606f68 slub: fix ksize() build error
mm/slub.c: In function 'ksize':
mm/slub.c:2728: error: implicit declaration of function 'slab_ksize'

slab_ksize() needs to go out of CONFIG_SLUB_DEBUG section.

Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Mariusz Kozlowski <mk@lab.zgora.pl>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-02-27 12:05:16 +02:00
Eric Dumazet b3d41885d9 slub: fix kmemcheck calls to match ksize() hints
Recent use of ksize() in network stack (commit ca44ac38 : net: don't
reallocate skb->head unless the current one hasn't the needed extra size
or is shared) triggers kmemcheck warnings, because ksize() can return
more space than kmemcheck is aware of.

Pekka Enberg noticed SLAB+kmemcheck is doing the right thing, while SLUB
+kmemcheck doesnt.

Bugzilla reference #27212

Reported-by: Christian Casteyde <casteyde.christian@free.fr>
Suggested-by: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Christoph Lameter <cl@linux.com>
CC: Changli Gao <xiaosuo@gmail.com>
CC: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-02-23 11:59:30 +02:00
Christoph Lameter 63310467a3 mm: Remove support for kmem_cache_name()
The last user was ext4 and Eric Sandeen removed the call in a recent patch. See
the following URL for the discussion:

http://marc.info/?l=linux-ext4&m=129546975702198&w=2

Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-01-23 21:00:05 +02:00
Pekka Enberg 597fb188cb Merge branch 'slub/hotplug' into slab/urgent 2011-01-15 13:28:17 +02:00
Joe Perches 62c70bce8a mm: convert sprintf_symbol to %pS
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: Jiri Kosina <trivial@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13 17:32:33 -08:00
Christoph Lameter 04d94879c8 slub: Avoid use of slub_lock in show_slab_objects()
The purpose of the locking is to prevent removal and additions
of nodes when statistics are gathered for a slab cache. So we
need to avoid racing with memory hotplug functionality.

It is enough to take the memory hotplug locks there instead
of the slub_lock.

online_pages() currently does not acquire the memory_hotplug
lock. Another patch will be submitted by the memory hotplug
authors to take the memory hotplug lock and describe the
uses of the memory hotplug lock to protect against
adding and removal of nodes from non hotplug data structures.

Cc: <stable@kernel.org> # 2.6.37
Reported-and-tested-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-01-11 17:09:53 +02:00
Linus Torvalds a1e8fad590 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6:
  slub: Fix a crash during slabinfo -v
  tracing/slab: Move kmalloc tracepoint out of inline code
  slub: Fix slub_lock down/up imbalance
  slub: Fix build breakage in Documentation/vm
  slub tracing: move trace calls out of always inlined functions to reduce kernel code size
  slub: move slabinfo.c to tools/slub/slabinfo.c
2011-01-10 08:38:01 -08:00
Nick Piggin ccd35fb9f4 kernel: kmem_ptr_validate considered harmful
This is a nasty and error prone API. It is no longer used, remove it.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:16 +11:00
Tero Roponen 37d57443d5 slub: Fix a crash during slabinfo -v
Commit f7cb193362 ("SLUB: Pass active
and inactive redzone flags instead of boolean to debug functions")
missed two instances of check_object(). This caused a lot of warnings
during 'slabinfo -v' finally leading to a crash:

  BUG ext4_xattr: Freepointer corrupt
  ...
  BUG buffer_head: Freepointer corrupt
  ...
  BUG ext4_alloc_context: Freepointer corrupt
  ...
  ...
  BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
  IP: [<ffffffff810a291f>] file_sb_list_del+0x1c/0x35
  PGD 79d78067 PUD 79e67067 PMD 0
  Oops: 0002 [#1] SMP
  last sysfs file: /sys/kernel/slab/:t-0000192/validate

This patch fixes the problem by converting the two missed instances.

Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tero Roponen <tero.roponen@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2010-12-04 09:53:49 +02:00
Tero Roponen 8165984acf slub: Fix a crash during slabinfo -v
Commit f7cb193362 ("SLUB: Pass active
and inactive redzone flags instead of boolean to debug functions")
missed two instances of check_object(). This caused a lot of warnings
during 'slabinfo -v' finally leading to a crash:

  BUG ext4_xattr: Freepointer corrupt
  ...
  BUG buffer_head: Freepointer corrupt
  ...
  BUG ext4_alloc_context: Freepointer corrupt
  ...
  ...
  BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
  IP: [<ffffffff810a291f>] file_sb_list_del+0x1c/0x35
  PGD 79d78067 PUD 79e67067 PMD 0
  Oops: 0002 [#1] SMP
  last sysfs file: /sys/kernel/slab/:t-0000192/validate

This patch fixes the problem by converting the two missed instances.

Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tero Roponen <tero.roponen@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2010-12-04 09:40:16 +02:00
Pavel Emelyanov 68cee4f118 slub: Fix slub_lock down/up imbalance
There are two places, that do not release the slub_lock.

Respective bugs were introduced by sysfs changes ab4d5ed5 (slub: Enable
sysfs support for !CONFIG_SLUB_DEBUG) and 2bce6485 ( slub: Allow removal
of slab caches during boot).

Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2010-11-14 16:53:11 +02:00
Pavel Emelyanov 98072e4d97 slub: Fix slub_lock down/up imbalance
There are two places, that do not release the slub_lock.

Respective bugs were introduced by sysfs changes ab4d5ed5 (slub: Enable
sysfs support for !CONFIG_SLUB_DEBUG) and 2bce6485 ( slub: Allow removal
of slab caches during boot).

Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2010-11-06 09:04:33 +02:00
Richard Kennedy 4a92379bdf slub tracing: move trace calls out of always inlined functions to reduce kernel code size
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: Richard Kennedy <richard@rsk.demon.co.uk>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2010-11-06 09:04:33 +02:00
Pekka Enberg 92a5bbc11f SLUB: Fix memory hotplug with !NUMA
This patch fixes the following build breakage when memory hotplug is enabled on
UMA configurations:

  /home/test/linux-2.6/mm/slub.c: In function 'kmem_cache_init':
  /home/test/linux-2.6/mm/slub.c:3031:2: error: 'slab_memory_callback'
  undeclared (first use in this function)
  /home/test/linux-2.6/mm/slub.c:3031:2: note: each undeclared
  identifier is reported only once for each function it appears in
  make[2]: *** [mm/slub.o] Error 1
  make[1]: *** [mm] Error 2
  make: *** [sub-make] Error 2

Reported-by: Zimny Lech <napohybelskurwysynom2010@gmail.com>
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2010-10-06 21:16:42 +03:00
Christoph Lameter a5a84755c5 slub: Move functions to reduce #ifdefs
There is a lot of #ifdef/#endifs that can be avoided if functions would be in different
places. Move them around and reduce #ifdef.

Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2010-10-06 16:54:37 +03:00
Christoph Lameter ab4d5ed5ee slub: Enable sysfs support for !CONFIG_SLUB_DEBUG
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: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2010-10-06 16:54:36 +03:00
Pekka Enberg 15b7c51420 SLUB: Optimize slab_free() debug check
This patch optimizes slab_free() debug check to use "c->node != NUMA_NO_NODE"
instead of "c->node >= 0" because the former generates smaller code on x86-64:

  Before:

    4736:       48 39 70 08             cmp    %rsi,0x8(%rax)
    473a:       75 26                   jne    4762 <kfree+0xa2>
    473c:       44 8b 48 10             mov    0x10(%rax),%r9d
    4740:       45 85 c9                test   %r9d,%r9d
    4743:       78 1d                   js     4762 <kfree+0xa2>

  After:

    4736:       48 39 70 08             cmp    %rsi,0x8(%rax)
    473a:       75 23                   jne    475f <kfree+0x9f>
    473c:       83 78 10 ff             cmpl   $0xffffffffffffffff,0x10(%rax)
    4740:       74 1d                   je     475f <kfree+0x9f>

This patch also cleans up __slab_alloc() to use NUMA_NO_NODE instead of "-1"
for enabling debugging for a per-CPU cache.

Acked-by: Christoph Lameter <cl@linux.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2010-10-06 16:52:26 +03:00
Namhyung Kim 5d1f57e4d3 slub: Move NUMA-related functions under CONFIG_NUMA
Make kmalloc_cache_alloc_node_notrace(), kmalloc_large_node()
and __kmalloc_node_track_caller() to be compiled only when
CONFIG_NUMA is selected.

Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2010-10-02 10:47:53 +03:00
Namhyung Kim 3478973ded slub: Add lock release annotation
The unfreeze_slab() releases page's PG_locked bit but was missing
proper annotation. The deactivate_slab() needs to be marked also
since it calls unfreeze_slab() without grabbing the lock.

Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2010-10-02 10:47:53 +03:00
Namhyung Kim a5dd5c117c slub: Fix signedness warnings
The bit-ops routines require its arg to be a pointer to unsigned long.
This leads sparse to complain about different signedness as follows:

 mm/slub.c:2425:49: warning: incorrect type in argument 2 (different signedness)
 mm/slub.c:2425:49:    expected unsigned long volatile *addr
 mm/slub.c:2425:49:    got long *map

Acked-by: Christoph Lameter <cl@linux.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2010-10-02 10:47:52 +03:00
Christoph Lameter 62e346a830 slub: extract common code to remove objects from partial list without locking
There are a couple of places where repeat the same statements when removing
a page from the partial list. Consolidate that into __remove_partial().

Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2010-10-02 10:44:10 +03:00
Christoph Lameter f7cb193362 SLUB: Pass active and inactive redzone flags instead of boolean to debug functions
Pass the actual values used for inactive and active redzoning to the
functions that check the objects. Avoids a lot of the ? : things to
lookup the values in the functions.

Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2010-10-02 10:44:10 +03:00
Christoph Lameter 7340cc8414 slub: reduce differences between SMP and NUMA
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: David Rientjes <rientjes@google.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2010-10-02 10:44:10 +03:00
Pekka Enberg ed59ecbf89 Revert "Slub: UP bandaid"
This reverts commit 5249d039500f05a5ab379286b1d23ab9b04d3f2c. It's not needed
after commit bbddff0545 ("percpu: use percpu
allocator on UP too").
2010-10-02 10:28:55 +03:00
Pekka Enberg 84c1cf6246 SLUB: Fix merged slab cache names
As explained by Linus "I'm Proud to be an American" Torvalds:

  Looking at the merging code, I actually think it's totally
  buggy. If you have something like this:

   - load module A: create slab cache A

   - load module B: create slab cache B that can merge with A

   - unload module A

   - "cat /proc/slabinfo": BOOM. Oops.

  exactly because the name is not handled correctly, and you'll have
  module B holding open a slab cache that has a name pointer that points
  to module A that no longer exists.

This patch fixes the problem by using kstrdup() to allocate dynamic memory for
->name of "struct kmem_cache" as suggested by Christoph Lameter.

Acked-by: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

Conflicts:

	mm/slub.c
2010-10-02 10:24:29 +03:00
Christoph Lameter db210e70e5 Slub: UP bandaid
Since the percpu allocator does not provide early allocation in UP mode (only
in SMP configurations) use __get_free_page() to improvise a compound page
allocation that can be later freed via kfree().

Compound pages will be released when the cpu caches are resized.

Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2010-10-02 10:24:29 +03:00
David Rientjes a016471a16 slub: fix SLUB_RESILIENCY_TEST for dynamic kmalloc caches
Now that the kmalloc_caches array is dynamically allocated at boot,
SLUB_RESILIENCY_TEST needs to be fixed to pass the correct type.

Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2010-10-02 10:24:29 +03:00
Christoph Lameter 8de66a0c02 slub: Fix up missing kmalloc_cache -> kmem_cache_node case for memoryhotplug
Memory hotplug allocates and frees per node structures. Use the correct name.

Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2010-10-02 10:24:28 +03:00
Christoph Lameter 7d550c56a2 slub: Add dummy functions for the !SLUB_DEBUG case
On Wed, 25 Aug 2010, Randy Dunlap wrote:
> mm/slub.c:1732: error: implicit declaration of function 'slab_pre_alloc_hook'
> mm/slub.c:1751: error: implicit declaration of function 'slab_post_alloc_hook'
> mm/slub.c:1881: error: implicit declaration of function 'slab_free_hook'
> mm/slub.c:1886: error: implicit declaration of function 'slab_free_hook_irq'

Empty functions are missing if the runtime debuggability option is compiled
out.

Provide the fall back functions to empty hooks if SLUB_DEBUG is not set.

Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2010-10-02 10:24:28 +03:00
Christoph Lameter c1d508365e slub: Move gfpflag masking out of the hotpath
Move the gfpflags masking into the hooks for checkers and into the slowpaths.
gfpflag masking requires access to a global variable and thus adds an
additional cacheline reference to the hotpaths.

If no hooks are active then the gfpflag masking will result in
code that the compiler can toss out.

Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2010-10-02 10:24:27 +03:00
Christoph Lameter c016b0bdee slub: Extract hooks for memory checkers from hotpaths
Extract the code that memory checkers and other verification tools use from
the hotpaths. Makes it easier to add new ones and reduces the disturbances
of the hotpaths.

Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2010-10-02 10:24:27 +03:00
Christoph Lameter 51df114281 slub: Dynamically size kmalloc cache allocations
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: David Rientjes <rientjes@google.com>
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2010-10-02 10:24:27 +03:00
Christoph Lameter 6c182dc0de slub: Remove static kmem_cache_cpu array for boot
The percpu allocator can now handle allocations during early boot.
So drop the static kmem_cache_cpu array.

Cc: Tejun Heo <tj@kernel.org>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2010-10-02 10:24:26 +03:00
Christoph Lameter 55136592fe slub: Remove dynamic dma slab allocation
Remove the dynamic dma slab allocation since this causes too many issues with
nested locks etc etc. The change avoids passing gfpflags into many functions.

V3->V4:
- Create dma caches in kmem_cache_init() instead of kmem_cache_init_late().

Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2010-10-02 10:24:26 +03:00
Christoph Lameter 1537066c69 slub: Force no inlining of debug functions
Compiler folds the debgging functions into the critical paths.
Avoid that by adding noinline to the functions that check for
problems.

Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2010-10-02 10:24:26 +03:00
Linus Torvalds b57bdda58c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6:
  slub: Allow removal of slab caches during boot
  Revert "slub: Allow removal of slab caches during boot"
  slub numa: Fix rare allocation from unexpected node
  slab: use deferable timers for its periodic housekeeping
  slub: Use kmem_cache flags to detect if slab is in debugging mode.
  slub: Allow removal of slab caches during boot
  slub: Check kasprintf results in kmem_cache_init()
  SLUB: Constants need UL
  slub: Use a constant for a unspecified node.
  SLOB: Free objects to their own list
  slab: fix caller tracking on !CONFIG_DEBUG_SLAB && CONFIG_TRACING
2010-08-06 11:44:08 -07:00
Pekka Enberg 415cb47998 Merge branches 'slab/fixes', 'slob/fixes', 'slub/cleanups' and 'slub/fixes' into for-linus 2010-08-04 22:04:43 +03:00
Christoph Lameter 2bce648584 slub: Allow removal of slab caches during boot
Serialize kmem_cache_create and kmem_cache_destroy using the slub_lock. Only
possible after the use of the slub_lock during dynamic dma creation has been
removed.

Then make sure that the setup of the slab sysfs entries does not race
with kmem_cache_create and kmem_cache destroy.

If a slab cache is removed before we have setup sysfs then simply skip over
the sysfs handling.

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Roland Dreier <rdreier@cisco.com>
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2010-08-03 07:28:32 +03:00
Pekka Enberg e438444de8 Revert "slub: Allow removal of slab caches during boot"
This reverts commit f5b801ac38.
2010-08-03 07:28:21 +03:00
Christoph Lameter bc6488e910 slub numa: Fix rare allocation from unexpected node
The network developers have seen sporadic allocations resulting in objects
coming from unexpected NUMA nodes despite asking for objects from a
specific node.

This is due to get_partial() calling get_any_partial() if partial
slabs are exhausted for a node even if a node was specified and therefore
one would expect allocations only from the specified node.

get_any_partial() sporadically may return a slab from a foreign
node to gradually reduce the size of partial lists on remote nodes
and thereby reduce total memory use for a slab cache.

The behavior is controlled by the remote_defrag_ratio of each cache.

Strictly speaking this is permitted behavior since __GFP_THISNODE was
not specified for the allocation but it is certain surprising.

This patch makes sure that the remote defrag behavior only occurs
if no node was specified.

Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2010-07-29 12:59:00 +03:00
Christoph Lameter af537b0a6c slub: Use kmem_cache flags to detect if slab is in debugging mode.
The cacheline with the flags is reachable from the hot paths after the
percpu allocator changes went in. So there is no need anymore to put a
flag into each slab page. Get rid of the SlubDebug flag and use
the flags in kmem_cache instead.

Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2010-07-16 11:13:08 +03:00
Christoph Lameter f5b801ac38 slub: Allow removal of slab caches during boot
If a slab cache is removed before we have setup sysfs then simply skip over
the sysfs handling.

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Roland Dreier <rdreier@cisco.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2010-07-16 11:13:07 +03:00
Christoph Lameter d7278bd7d1 slub: Check kasprintf results in kmem_cache_init()
Small allocations may fail during slab bringup which is fatal. Add a BUG_ON()
so that we fail immediately rather than failing later during sysfs
processing.

Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2010-07-16 11:13:07 +03:00
Christoph Lameter f90ec39014 SLUB: Constants need UL
UL suffix is missing in some constants. Conform to how slab.h uses constants.

Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2010-07-16 11:13:07 +03:00
Christoph Lameter 2154a33638 slub: Use a constant for a unspecified node.
kmalloc_node() and friends can be passed a constant -1 to indicate
that no choice was made for the node from which the object needs to
come.

Use NUMA_NO_NODE instead of -1.

CC: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2010-07-16 11:13:06 +03:00
Ingo Molnar c726b61c6a Merge branch 'perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing into perf/core 2010-06-09 18:55:57 +02:00
Li Zefan 039ca4e74a tracing: Remove kmemtrace ftrace plugin
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: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Eduard - 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: Frederic Weisbecker <fweisbec@gmail.com>
2010-06-09 17:31:22 +02:00
Linus Torvalds 3b03117c5c Merge branch 'slub/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6
* 'slub/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6:
  SLUB: Allow full duplication of kmalloc array for 390
  slub: move kmem_cache_node into it's own cacheline
2010-05-30 12:46:17 -07:00
Miao Xie c0ff7453bb cpuset,mm: fix no node to alloc memory when changing cpuset's mems
Before applying this patch, cpuset updates task->mems_allowed and
mempolicy by setting all new bits in the nodemask first, and clearing all
old unallowed bits later.  But in the way, the allocator may find that
there is no node to alloc memory.

The reason is that cpuset rebinds the task's mempolicy, it cleans the
nodes which the allocater can alloc pages on, for example:

(mpol: mempolicy)
	task1			task1's mpol	task2
	alloc page		1
	  alloc on node0? NO	1
				1		change mems from 1 to 0
				1		rebind task1's mpol
				0-1		  set new bits
				0	  	  clear disallowed bits
	  alloc on node1? NO	0
	  ...
	can't alloc page
	  goto oom

This patch fixes this problem by expanding the nodes range first(set newly
allowed bits) and shrink it lazily(clear newly disallowed bits).  So we
use a variable to tell the write-side task that read-side task is reading
nodemask, and the write-side task clears newly disallowed nodes after
read-side task ends the current memory allocation.

[akpm@linux-foundation.org: fix spello]
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Paul Menage <menage@google.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Ravikiran Thirumalai <kiran@scalex86.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:06:57 -07:00
Alexander Duyck 73367bd8ee slub: move kmem_cache_node into it's own cacheline
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: Alex Shi <alex.shi@intel.com>
Tested-by: Alex Shi <alex.shi@intel.com>
Acked-by: Yanmin Zhang <yanmin_zhang@linux.intel.com>
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2010-05-24 21:11:29 +03:00
Pekka Enberg bb4f6b0cd7 Merge branches 'slab/align', 'slab/cleanups', 'slab/fixes', 'slab/memhotadd' and 'slub/fixes' into slab-for-linus 2010-05-22 10:57:52 +03:00
Minchan Kim 6b65aaf302 slub: Use alloc_pages_exact_node() for page allocation
The alloc_slab_page() in SLUB uses alloc_pages() if node is '-1'.  This means
that node validity check in alloc_pages_node is unnecessary and we can use
alloc_pages_exact_node() to avoid comparison and branch as commit
6484eb3e2a ("page allocator: do not check NUMA node ID when the caller
knows the node is valid") did for the page allocator.

Cc: Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2010-05-22 10:57:31 +03:00
Xiaotian Feng d3e14aa336 slub: __kmalloc_node_track_caller should trace kmalloc_large_node case
commit 94b528d (kmemtrace: SLUB hooks for caller-tracking functions)
missed tracing kmalloc_large_node in __kmalloc_node_track_caller. We
should trace it same as __kmalloc_node.

Acked-by: David Rientjes <rientjes@google.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Vegard Nossum <vegard.nossum@gmail.com>
Signed-off-by: Xiaotian Feng <dfeng@redhat.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2010-05-22 10:57:31 +03:00
Eric Dumazet bbd7d57bfe slub: Potential stack overflow
I discovered that we can overflow stack if CONFIG_SLUB_DEBUG=y and use slabs
with many objects, since list_slab_objects() and process_slab() use
DECLARE_BITMAP(map, page->objects).

With 65535 bits, we use 8192 bytes of stack ...

Switch these allocations to dynamic allocations.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2010-05-22 10:57:30 +03:00
David Woodhouse 4581ced379 mm: Move ARCH_SLAB_MINALIGN and ARCH_KMALLOC_MINALIGN to <linux/slub_def.h>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2010-05-19 22:03:13 +03:00