Signed-off-by: NChristopher Li <sparse@chrisli.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

remoteproc.txt should have been .h
Signed-off-by: NJoe Perches <joe@perches.com>
Cc: Ohad Ben-Cohen <ohad@wizery.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

As described in e6fa16ab ("signal: sigprocmask() should do
retarget_shared_pending()") the modification of current->blocked is
incorrect as we need to check for shared signals we're about to block.

Also, use the new helper function introduced in commit 5e6292c0
("signal: add block_sigmask() for adding sigmask to current->blocked")
which centralises the code for updating current->blocked after
successfully delivering a signal and reduces the amount of duplicate
code across architectures.  In the past some architectures got this code
wrong, so using this helper function should stop that from happening
again.

Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: NOleg Nesterov <oleg@redhat.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Many users of debugfs copy the implementation of default_open() when
they want to support a custom read/write function op.  This leads to a
proliferation of the default_open() implementation across the entire
tree.

Now that the common implementation has been consolidated into libfs we
can replace all the users of this function with simple_open().

This replacement was done with the following semantic patch:

<smpl>
@ open @
identifier open_f != simple_open;
identifier i, f;
@@
-int open_f(struct inode *i, struct file *f)
-{
(
-if (i->i_private)
-f->private_data = i->i_private;
|
-f->private_data = i->i_private;
)
-return 0;
-}

@ has_open depends on open @
identifier fops;
identifier open.open_f;
@@
struct file_operations fops = {
...
-.open = open_f,
+.open = simple_open,
...
};
</smpl>

[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Acked-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Find instances of an open-coded simple_open() and replace them with
calls to simple_open().
Signed-off-by: NJulia Lawall <Julia.Lawall@lip6.fr>
Reported-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

debugfs and a few other drivers use an open-coded version of
simple_open() to pass a pointer from the file to the read/write file
ops.  Add support for this simple case to libfs so that we can remove
the many duplicate copies of this simple function.
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

It was introduced by d1d5e05f ("hugetlbfs: return error code when
initializing module") but as Al pointed out, is a bad idea.

Quoted comments from Al:
 "Note that unregister_filesystem() in module init is *always* wrong;
  it's not an issue here (it's done too early to care about and
  realistically the box is not going anywhere - it'll panic when attempt
  to exec /sbin/init fails, if not earlier), but it's a damn bad
  example.

  Consider a normal fs module.  Somebody loads it and in parallel with
  that we get a mount attempt on that fs type.  It comes between
  register and failure exits that causes unregister; at that point we
  are screwed since grabbing a reference to module as done by mount is
  enough to prevent exit, but not to prevent the failure of init.  As
  the result, module will get freed when init fails, mounted fs of that
  type be damned."

So remove it.
Signed-off-by: NHillf Danton <dhillf@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

According to 88pm860x spec, rtc alarm irq enable control is bit3 for
RTC_ALARM_EN, so fix it.
Signed-off-by: NJett.Zhou <jtzhou@marvell.com>
Cc: Axel Lin <axel.lin@gmail.com>
Cc: Haojian Zhuang <haojian.zhuang@marvell.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This allocation can be as large as 64k.

 - Add __GFP_NOWARN so the a falied kmalloc() is silent

 - Fall back to vmalloc() if the kmalloc() failed

Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: David Rientjes <rientjes@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This allocation can be as large as 64k.  As David points out, "falling
back to vmalloc here is much better solution than failing to retreive
the attribute - it will work no matter how fragmented memory gets.  That
means we don't get incomplete backups occurring after days or months of
uptime and successful backups".

Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: David Rientjes <rientjes@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This size is user controllable, up to a maximum of XATTR_LIST_MAX (64k).
So it's trivial for someone to trigger a stream of order:4 page
allocation errors.
Signed-off-by: NDave Jones <davej@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dave Chinner <david@fromorbit.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Change send_sig_all() to use do_send_sig_info(SEND_SIG_FORCED) instead
of force_sig(SIGKILL).  With the recent changes we do not need force_ to
kill the CLONE_NEWPID tasks.

And this is more correct.  force_sig() can race with the exiting thread,
while do_send_sig_info(group => true) kill the whole process.

Some more notes from Oleg Nesterov:

> Just one note. This change makes no difference for sysrq_handle_kill().
> But it obviously changes the behaviour sysrq_handle_term(). I think
> this is fine, if you want to really kill the task which blocks/ignores
> SIGTERM you can use sysrq_handle_kill().
>
> Even ignoring the reasons why force_sig() is simply wrong here,
> force_sig(SIGTERM) looks strange. The task won't be killed if it has
> a handler, but SIG_IGN can't help. However if it has the handler
> but blocks SIGTERM temporary (this is very common) it will be killed.

Also,

> force_sig() can't kill the process if the main thread has already
> exited. IOW, it is trivial to create the process which can't be
> killed by sysrq.

So, this patch fixes the issue.
Suggested-by: NOleg Nesterov <oleg@redhat.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: NOleg Nesterov <oleg@redhat.com>
Signed-off-by: NAnton Vorontsov <anton.vorontsov@linaro.org>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The proc_parse_options() call from proc_mount() runs only once at boot
time.  So on any later mount attempt, any mount options are ignored
because ->s_root is already initialized.

As a consequence, "mount -o <options>" will ignore the options.  The
only way to change mount options is "mount -o remount,<options>".

To fix this, parse the mount options unconditionally.
Signed-off-by: NVasiliy Kulikov <segoon@openwall.com>
Reported-by: NArkadiusz Miskiewicz <a.miskiewicz@gmail.com>
Tested-by: NArkadiusz Miskiewicz <a.miskiewicz@gmail.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 025c5b24 ("thp: optimize away unnecessary page table
locking") moves spin_lock() into pmd_trans_huge_lock() in order to avoid
locking unless pmd is for thp.  So this spin_lock() is a bug.
Reported-by: NSasha Levin <levinsasha928@gmail.com>
Signed-off-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix typo in drivers/video/backlight/tosa_lcd.c
"tosa_lcd_reume" should be "tosa_lcd_resume".
Signed-off-by: NMasanari Iida <standby24x7@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add help text to the crc32 algorithm selection option in Kconfig.
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Reported-by: NStefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

hugepage-mmap.c, hugepage-shm.c and map_hugetlb.c in Documentation/vm are
simple pass/fail tests, It's better to promote them to
tools/testing/selftests.

Thanks suggestion of Andrew Morton about this.  They all need firstly
setting up proper nr_hugepages and hugepage-mmap need to mount hugetlbfs.
So I add a shell script run_vmtests to do such work which will call the
three test programs and check the return value of them.

Changes to original code including below:
a. add run_vmtests script
b. return error when read_bytes mismatch with writed bytes.
c. coding style fixes: do not use assignment in if condition

[akpm@linux-foundation.org: build the targets before trying to execute them]
[akpm@linux-foundation.org: Documentation/vm/ no longer has a Makefile. Fixes "make clean"]
Signed-off-by: NDave Young <dyoung@redhat.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We have tools/vm/ folder for vm tools, so move slabinfo.c from tools/slub/
to tools/vm/
Signed-off-by: NDave Young <dyoung@redhat.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Acked-by: NChristoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

tools/ is the better place for vm tools which are used by many people.
Moving them to tools also make them open to more users instead of hide in
Documentation folder.

This patch moves page-types.c to tools/vm/page-types.c.  Also add a
Makefile in tools/vm and fix two coding style problems: a) change const
arrary to 'const char * const', b) change a space to tab for indent.
Signed-off-by: NDave Young <dyoung@redhat.com>
Acked-by: NWu Fengguang <fengguang.wu@intel.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

So a "make run_tests" will build the tests before trying to run them.
Acked-by: NFrederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Remove the run_tests script and launch the selftests by calling "make
run_tests" from the selftests top directory instead.  This delegates to
the Makefile in each selftest directory, where it is decided how to launch
the local test.

This removes the need to add each selftest directory to the now removed
"run_tests" top script.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Replace radix_tree_gang_lookup_slot() and
radix_tree_gang_lookup_tag_slot() in page-cache lookup functions with
brand-new radix-tree direct iterating.  This avoids the double-scanning
and pointer copying.

Iterator don't stop after nr_pages page-get fails in a row, it continue
lookup till the radix-tree end.  Thus we can safely remove these restart
conditions.

Unfortunately, old implementation didn't forbid nr_pages == 0, this corner
case does not fit into new code, so the patch adds an extra check at the
beginning.
Signed-off-by: NKonstantin Khlebnikov <khlebnikov@openvz.org>
Tested-by: NHugh Dickins <hughd@google.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Rewrite radix_tree_gang_lookup_* functions using the new radix-tree
iterator.
Signed-off-by: NKonstantin Khlebnikov <khlebnikov@openvz.org>
Tested-by: NHugh Dickins <hughd@google.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

A series of radix tree cleanups, and usage of them in the core pagecache
code.

Micro-benchmark:

lookup 14 slots (typical page-vector size)
in radix-tree there earch <step> slot filled and tagged
before/after - nsec per full scan through tree

* Intel Sandy Bridge i7-2620M 4Mb L3
New code always faster

* AMD Athlon 6000+ 2x1Mb L2, without L3
New code generally faster,
Minor degradation (marked with "*") for huge sparse trees

* i386 on Sandy Bridge
New code faster for common cases: tagged and dense trees.
Some degradations for non-tagged lookup on sparse trees.

Ideally, there might help __ffs() analog for searching first non-zero
long element in array, gcc sometimes cannot optimize this loop corretly.

Numbers:

CPU: Intel Sandy Bridge i7-2620M 4Mb L3

radix-tree with 1024 slots:

tagged lookup

step  1      before  7156        after  3613
step  2      before  5399        after  2696
step  3      before  4779        after  1928
step  4      before  4456        after  1429
step  5      before  4292        after  1213
step  6      before  4183        after  1052
step  7      before  4157        after  951
step  8      before  4016        after  812
step  9      before  3952        after  851
step  10     before  3937        after  732
step  11     before  4023        after  709
step  12     before  3872        after  657
step  13     before  3892        after  633
step  14     before  3720        after  591
step  15     before  3879        after  578
step  16     before  3561        after  513

normal lookup

step  1      before  4266       after  3301
step  2      before  2695       after  2129
step  3      before  2083       after  1712
step  4      before  1801       after  1534
step  5      before  1628       after  1313
step  6      before  1551       after  1263
step  7      before  1475       after  1185
step  8      before  1432       after  1167
step  9      before  1373       after  1092
step  10     before  1339       after  1134
step  11     before  1292       after  1056
step  12     before  1319       after  1030
step  13     before  1276       after  1004
step  14     before  1256       after  987
step  15     before  1228       after  992
step  16     before  1247       after  999

radix-tree with 1024*1024*128 slots:

tagged lookup

step  1      before  1086102841  after  674196409
step  2      before  816839155   after  498138306
step  7      before  599728907   after  240676762
step  15     before  555729253   after  185219677
step  63     before  606637748   after  128585664
step  64     before  608384432   after  102945089
step  65     before  596987114   after  123996019
step  128    before  304459225   after  56783056
step  256    before  158846855   after  31232481
step  512    before  86085652    after  18950595
step  12345  before  6517189     after  1674057

normal lookup

step  1      before  626064869  after  544418266
step  2      before  418809975  after  336321473
step  7      before  242303598  after  207755560
step  15     before  208380563  after  176496355
step  63     before  186854206  after  167283638
step  64     before  176188060  after  170143976
step  65     before  185139608  after  167487116
step  128    before  88181865   after  86913490
step  256    before  45733628   after  45143534
step  512    before  24506038   after  23859036
step  12345  before  2177425    after  2018662

* AMD Athlon 6000+ 2x1Mb L2, without L3

radix-tree with 1024 slots:

tag-lookup

step  1      before  8164        after  5379
step  2      before  5818        after  5581
step  3      before  4959        after  4213
step  4      before  4371        after  3386
step  5      before  4204        after  2997
step  6      before  4950        after  2744
step  7      before  4598        after  2480
step  8      before  4251        after  2288
step  9      before  4262        after  2243
step  10     before  4175        after  2131
step  11     before  3999        after  2024
step  12     before  3979        after  1994
step  13     before  3842        after  1929
step  14     before  3750        after  1810
step  15     before  3735        after  1810
step  16     before  3532        after  1660

normal-lookup

step  1      before  7875        after  5847
step  2      before  4808        after  4071
step  3      before  4073        after  3462
step  4      before  3677        after  3074
step  5      before  4308        after  2978
step  6      before  3911        after  3807
step  7      before  3635        after  3522
step  8      before  3313        after  3202
step  9      before  3280        after  3257
step  10     before  3166        after  3083
step  11     before  3066        after  3026
step  12     before  2985        after  2982
step  13     before  2925        after  2924
step  14     before  2834        after  2808
step  15     before  2805        after  2803
step  16     before  2647        after  2622

radix-tree with 1024*1024*128 slots:

tag-lookup

step  1      before  1288059720  after  951736580
step  2      before  961292300   after  884212140
step  7      before  768905140   after  547267580
step  15     before  771319480   after  456550640
step  63     before  504847640   after  242704304
step  64     before  392484800   after  177920786
step  65     before  491162160   after  246895264
step  128    before  208084064   after  97348392
step  256    before  112401035   after  51408126
step  512    before  75825834    after  29145070
step  12345  before  5603166     after  2847330

normal-lookup

step  1      before  1025677120  after  861375100
step  2      before  647220080   after  572258540
step  7      before  505518960   after  484041813
step  15     before  430483053   after  444815320	*
step  63     before  388113453   after  404250546	*
step  64     before  374154666   after  396027440	*
step  65     before  381423973   after  396704853	*
step  128    before  190078700   after  202619384	*
step  256    before  100886756   after  102829108	*
step  512    before  64074505    after  56158720
step  12345  before  4237289     after  4422299		*

* i686 on Sandy bridge

radix-tree with 1024 slots:

tagged lookup

step  1      before  7990        after  4019
step  2      before  5698        after  2897
step  3      before  5013        after  2475
step  4      before  4630        after  1721
step  5      before  4346        after  1759
step  6      before  4299        after  1556
step  7      before  4098        after  1513
step  8      before  4115        after  1222
step  9      before  3983        after  1390
step  10     before  4077        after  1207
step  11     before  3921        after  1231
step  12     before  3894        after  1116
step  13     before  3840        after  1147
step  14     before  3799        after  1090
step  15     before  3797        after  1059
step  16     before  3783        after  745

normal lookup

step  1      before  5103       after  3499
step  2      before  3299       after  2550
step  3      before  2489       after  2370
step  4      before  2034       after  2302		*
step  5      before  1846       after  2268		*
step  6      before  1752       after  2249		*
step  7      before  1679       after  2164		*
step  8      before  1627       after  2153		*
step  9      before  1542       after  2095		*
step  10     before  1479       after  2109		*
step  11     before  1469       after  2009		*
step  12     before  1445       after  2039		*
step  13     before  1411       after  2013		*
step  14     before  1374       after  2046		*
step  15     before  1340       after  1975		*
step  16     before  1331       after  2000		*

radix-tree with 1024*1024*128 slots:

tagged lookup

step  1      before  1225865377  after  667153553
step  2      before  842427423   after  471533007
step  7      before  609296153   after  276260116
step  15     before  544232060   after  226859105
step  63     before  519209199   after  141343043
step  64     before  588980279   after  141951339
step  65     before  521099710   after  138282060
step  128    before  298476778   after  83390628
step  256    before  149358342   after  43602609
step  512    before  76994713    after  22911077
step  12345  before  53286669     after  1472111

normal lookup

step  1      before  819284564  after  533635310
step  2      before  512421605  after  364956155
step  7      before  271443305  after  305721345	*
step  15     before  223591630  after  273960216	*
step  63     before  190320247  after  217770207	*
step  64     before  178538168  after  267411372	*
step  65     before  186400423  after  215347937	*
step  128    before  88106045   after  140540612	*
step  256    before  44812420   after  70660377		*
step  512    before  24435438   after  36328275		*
step  12345  before  2123924    after  2148062		*

bloat-o-meter delta for this patchset + patchset with related shmem cleanups

bloat-o-meter: x86_64

add/remove: 4/3 grow/shrink: 5/6 up/down: 928/-939 (-11)
function                                     old     new   delta
radix_tree_next_chunk                          -     499    +499
shmem_unuse                                  428     554    +126
shmem_radix_tree_replace                     131     227     +96
find_get_pages_tag                           354     419     +65
find_get_pages_contig                        345     407     +62
find_get_pages                               362     396     +34
__kstrtab_radix_tree_next_chunk                -      22     +22
__ksymtab_radix_tree_next_chunk                -      16     +16
__kcrctab_radix_tree_next_chunk                -       8      +8
radix_tree_gang_lookup_slot                  204     203      -1
static.shmem_xattr_set                       384     381      -3
radix_tree_gang_lookup_tag_slot              208     191     -17
radix_tree_gang_lookup                       231     187     -44
radix_tree_gang_lookup_tag                   247     199     -48
shmem_unlock_mapping                         278     190     -88
__lookup                                     217       -    -217
__lookup_tag                                 242       -    -242
radix_tree_locate_item                       279       -    -279

bloat-o-meter: i386

add/remove: 3/3 grow/shrink: 8/9 up/down: 1075/-1275 (-200)
function                                     old     new   delta
radix_tree_next_chunk                          -     757    +757
shmem_unuse                                  352     449     +97
find_get_pages_contig                        269     322     +53
shmem_radix_tree_replace                     113     154     +41
find_get_pages_tag                           277     318     +41
dcache_dir_lseek                             426     458     +32
__kstrtab_radix_tree_next_chunk                -      22     +22
vc_do_resize                                 968     977      +9
snd_pcm_lib_read1                            725     733      +8
__ksymtab_radix_tree_next_chunk                -       8      +8
netlbl_cipsov4_list                         1120    1127      +7
find_get_pages                               293     291      -2
new_slab                                     467     459      -8
bitfill_unaligned_rev                        425     417      -8
radix_tree_gang_lookup_tag_slot              177     146     -31
blk_dump_cmd                                 267     229     -38
radix_tree_gang_lookup_slot                  212     134     -78
shmem_unlock_mapping                         221     128     -93
radix_tree_gang_lookup_tag                   275     162    -113
radix_tree_gang_lookup                       255     126    -129
__lookup                                     227       -    -227
__lookup_tag                                 271       -    -271
radix_tree_locate_item                       277       -    -277

This patch:

Implement a clean, simple and effective radix-tree iteration routine.

Iterating divided into two phases:
* lookup next chunk in radix-tree leaf node
* iterating through slots in this chunk

Main iterator function radix_tree_next_chunk() returns pointer to first
slot, and stores in the struct radix_tree_iter index of next-to-last slot.
 For tagged-iterating it also constuct bitmask of tags for retunted chunk.
 All additional logic implemented as static-inline functions and macroses.

Also adds radix_tree_find_next_bit() static-inline variant of
find_next_bit() optimized for small constant size arrays, because
find_next_bit() too heavy for searching in an array with one/two long
elements.

[akpm@linux-foundation.org: rework comments a bit]
Signed-off-by: NKonstantin Khlebnikov <khlebnikov@openvz.org>
Tested-by: NHugh Dickins <hughd@google.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If CONFIG_NET_NS, CONFIG_UTS_NS and CONFIG_IPC_NS are disabled,
ns_entries[] becomes empty and things like
ns_entries[ARRAY_SIZE(ns_entries) - 1] will explode.
Reported-by: NRichard Weinberger <richard@nod.at>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Daniel Lezcano <daniel.lezcano@free.fr>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

rename the nbd_device variable from "lo" to "nbd", since "lo" is just a name
copied from loop.c.
Signed-off-by: NWanlong Gao <gaowanlong@cn.fujitsu.com>
Cc: Paul Clements <paul.clements@steeleye.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In the case of a child pid namespace, rebooting the system does not really
makes sense.  When the pid namespace is used in conjunction with the other
namespaces in order to create a linux container, the reboot syscall leads
to some problems.

A container can reboot the host.  That can be fixed by dropping the
sys_reboot capability but we are unable to correctly to poweroff/
halt/reboot a container and the container stays stuck at the shutdown time
with the container's init process waiting indefinitively.

After several attempts, no solution from userspace was found to reliabily
handle the shutdown from a container.

This patch propose to make the init process of the child pid namespace to
exit with a signal status set to : SIGINT if the child pid namespace
called "halt/poweroff" and SIGHUP if the child pid namespace called
"reboot".  When the reboot syscall is called and we are not in the initial
pid namespace, we kill the pid namespace for "HALT", "POWEROFF",
"RESTART", and "RESTART2".  Otherwise we return EINVAL.

Returning EINVAL is also an easy way to check if this feature is supported
by the kernel when invoking another 'reboot' option like CAD.

By this way the parent process of the child pid namespace knows if it
rebooted or not and can take the right decision.

Test case:
==========

#include <alloca.h>
#include <stdio.h>
#include <sched.h>
#include <unistd.h>
#include <signal.h>
#include <sys/reboot.h>
#include <sys/types.h>
#include <sys/wait.h>

#include <linux/reboot.h>

static int do_reboot(void *arg)
{
        int *cmd = arg;

        if (reboot(*cmd))
                printf("failed to reboot(%d): %m\n", *cmd);
}

int test_reboot(int cmd, int sig)
{
        long stack_size = 4096;
        void *stack = alloca(stack_size) + stack_size;
        int status;
        pid_t ret;

        ret = clone(do_reboot, stack, CLONE_NEWPID | SIGCHLD, &cmd);
        if (ret < 0) {
                printf("failed to clone: %m\n");
                return -1;
        }

        if (wait(&status) < 0) {
                printf("unexpected wait error: %m\n");
                return -1;
        }

        if (!WIFSIGNALED(status)) {
                printf("child process exited but was not signaled\n");
                return -1;
        }

        if (WTERMSIG(status) != sig) {
                printf("signal termination is not the one expected\n");
                return -1;
        }

        return 0;
}

int main(int argc, char *argv[])
{
        int status;

        status = test_reboot(LINUX_REBOOT_CMD_RESTART, SIGHUP);
        if (status < 0)
                return 1;
        printf("reboot(LINUX_REBOOT_CMD_RESTART) succeed\n");

        status = test_reboot(LINUX_REBOOT_CMD_RESTART2, SIGHUP);
        if (status < 0)
                return 1;
        printf("reboot(LINUX_REBOOT_CMD_RESTART2) succeed\n");

        status = test_reboot(LINUX_REBOOT_CMD_HALT, SIGINT);
        if (status < 0)
                return 1;
        printf("reboot(LINUX_REBOOT_CMD_HALT) succeed\n");

        status = test_reboot(LINUX_REBOOT_CMD_POWER_OFF, SIGINT);
        if (status < 0)
                return 1;
        printf("reboot(LINUX_REBOOT_CMD_POWERR_OFF) succeed\n");

        status = test_reboot(LINUX_REBOOT_CMD_CAD_ON, -1);
        if (status >= 0) {
                printf("reboot(LINUX_REBOOT_CMD_CAD_ON) should have failed\n");
                return 1;
        }
        printf("reboot(LINUX_REBOOT_CMD_CAD_ON) has failed as expected\n");

        return 0;
}

[akpm@linux-foundation.org: tweak and add comments]
[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: NDaniel Lezcano <daniel.lezcano@free.fr>
Acked-by: NSerge Hallyn <serge.hallyn@canonical.com>
Tested-by: NSerge Hallyn <serge.hallyn@canonical.com>
Reviewed-by: NOleg Nesterov <oleg@redhat.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use bitmap_set() instead of using set_bit() for each bit.  This conversion
is valid because the bitmap is private in the function call and atomic
bitops were unnecessary.

This also includes minor change.
- Use bitmap_copy() for shorter typing
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The IPMI watchdog timer clears or extends the timer on reboot/shutdown.
It was using the non-locking routine for setting the watchdog timer, but
this was causing race conditions.  Instead, use the locking version to
avoid the races.  It seems to work fine.
Signed-off-by: NCorey Minyard <cminyard@mvista.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Now that the the IPMI driver is using a tasklet, we can simplify the
locking in the driver and get rid of the message lock.
Signed-off-by: NCorey Minyard <cminyard@mvista.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The part of the IPMI driver that delivered panic information to the event
log and extended the watchdog timeout during a panic was not properly
handling the messages.  It used static messages to avoid allocation, but
wasn't properly waiting for these, or wasn't properly handling the
refcounts.
Signed-off-by: NCorey Minyard <cminyard@mvista.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The IPMI driver would release a lock, deliver a message, then relock.
This is obviously ugly, and this patch converts the message handler
interface to use a tasklet to schedule work.  This lets the receive
handler be called from an interrupt handler with interrupts enabled.
Signed-off-by: NCorey Minyard <cminyard@mvista.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We currently time out and retry KCS transactions after 1 second of waiting
for IBF or OBF.  This appears to be too short for some hardware.  The IPMI
spec says "All system software wait loops should include error timeouts.
For simplicity, such timeouts are not shown explicitly in the flow
diagrams.  A five-second timeout or greater is recommended".  Change the
timeout to five seconds to satisfy the slow hardware.
Signed-off-by: NMatthew Garrett <mjg@redhat.com>
Signed-off-by: NCorey Minyard <cminyard@mvista.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Call the event handler immediately after starting the next message.

This change considerably decreases the IPMI transaction time (cuts off
~9ms for a single ipmitool transaction).
Signed-off-by: NSrinivas_Gowda <srinivas_g_gowda@dell.com>
Signed-off-by: NCorey Minyard <cminyard@mvista.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

crashkernel reservation need know the total memory size.  Current
get_total_mem simply use max_pfn - min_low_pfn.  It is wrong because it
will including memory holes in the middle.

Especially for kvm guest with memory > 0xe0000000, there's below in qemu
code: qemu split memory as below:

    if (ram_size >= 0xe0000000 ) {
        above_4g_mem_size = ram_size - 0xe0000000;
        below_4g_mem_size = 0xe0000000;
    } else {
        below_4g_mem_size = ram_size;
    }

So for 4G mem guest, seabios will insert a 512M usable region beyond of
4G.  Thus in above case max_pfn - min_low_pfn will be more than original
memsize.

Fixing this issue by using memblock_phys_mem_size() to get the total
memsize.
Signed-off-by: NDave Young <dyoung@redhat.com>
Reviewed-by: NWANG Cong <xiyou.wangcong@gmail.com>
Reviewed-by: NSimon Horman <horms@verge.net.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When using crashkernel=2M-256M, the kernel doesn't give any warning.  This
is misleading sometimes.
Signed-off-by: NZhenzhong Duan <zhenzhong.duan@oracle.com>
Acked-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

nommu platforms don't have very interesting swapper_pg_dir pointers and
usually just #define them to NULL, meaning that we can't include them in
the vmcoreinfo on the kexec crash path.

This patch only saves the swapper_pg_dir if we have an MMU.
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Reviewed-by: NSimon Horman <horms@verge.net.au>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This was marked as obsolete for quite a while now..  Now it is time to
remove it altogether.  And while doing this, get rid of first_cpu() as
well.  Also, remove the redundant setting of cpu_online_mask in
smp_prepare_cpus() because the generic code would have already set cpu 0
in cpu_online_mask.
Reported-by: NTony Luck <tony.luck@intel.com>
Signed-off-by: NSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

__any_online_cpu() is not optimal and also unnecessary.  So, replace its
use by faster cpumask_* operations.
Signed-off-by: NSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Venkatesh Pallipadi <venki@google.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Calculate a cpumask of CPUs with per-cpu pages in any zone and only send
an IPI requesting CPUs to drain these pages to the buddy allocator if they
actually have pages when asked to flush.

This patch saves 85%+ of IPIs asking to drain per-cpu pages in case of
severe memory pressure that leads to OOM since in these cases multiple,
possibly concurrent, allocation requests end up in the direct reclaim code
path so when the per-cpu pages end up reclaimed on first allocation
failure for most of the proceeding allocation attempts until the memory
pressure is off (possibly via the OOM killer) there are no per-cpu pages
on most CPUs (and there can easily be hundreds of them).

This also has the side effect of shortening the average latency of direct
reclaim by 1 or more order of magnitude since waiting for all the CPUs to
ACK the IPI takes a long time.

Tested by running "hackbench 400" on a 8 CPU x86 VM and observing the
difference between the number of direct reclaim attempts that end up in
drain_all_pages() and those were more then 1/2 of the online CPU had any
per-cpu page in them, using the vmstat counters introduced in the next
patch in the series and using proc/interrupts.

In the test sceanrio, this was seen to save around 3600 global
IPIs after trigerring an OOM on a concurrent workload:

$ cat /proc/vmstat | tail -n 2
pcp_global_drain 0
pcp_global_ipi_saved 0

$ cat /proc/interrupts | grep CAL
CAL:          1          2          1          2
          2          2          2          2   Function call interrupts

$ hackbench 400
[OOM messages snipped]

$ cat /proc/vmstat | tail -n 2
pcp_global_drain 3647
pcp_global_ipi_saved 3642

$ cat /proc/interrupts | grep CAL
CAL:          6         13          6          3
          3          3         1 2          7   Function call interrupts

Please note that if the global drain is removed from the direct reclaim
path as a patch from Mel Gorman currently suggests this should be replaced
with an on_each_cpu_cond invocation.
Signed-off-by: NGilad Ben-Yossef <gilad@benyossef.com>
Acked-by: NMel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: NChristoph Lameter <cl@linux.com>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Acked-by: NMichal Nazarewicz <mina86@mina86.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>