Commit graph

3279 commits

Author SHA1 Message Date
Linus Torvalds
77493bd9b2 Merge branch 'stable/for-linus-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb
Pull swiotlb fix from Konrad Rzeszutek Wilk:
 "Tiny little fix which just converts an function to be static.  Really
  tiny"

* 'stable/for-linus-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb:
  swiotlb: do not export map_single function
2015-06-06 09:06:20 -07:00
Alexandre Courbot
023600f192 swiotlb: do not export map_single function
The map_single() function is not defined as static, even though it
doesn't seem to be used anywhere else in the kernel. Make it static to
avoid namespace pollution since this is a rather generic symbol.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2015-06-05 18:46:30 -04:00
Jan Kara
226a07ef0a lib: Clarify the return value of strnlen_user()
strnlen_user() can return a number in a range 0 to count +
sizeof(unsigned long) - 1. Clarify the comment at the top of the
function so that users don't think the function returns at most count+1.

Signed-off-by: Jan Kara <jack@suse.cz>
[ Also added commentary about preferably not using this function ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-03 08:00:22 -07:00
Jan Kara
f18c34e483 lib: Fix strnlen_user() to not touch memory after specified maximum
If the specified maximum length of the string is a multiple of unsigned
long, we would load one long behind the specified maximum.  If that
happens to be in a next page, we can hit a page fault although we were
not expected to.

Fix the off-by-one bug in the test whether we are at the end of the
specified range.

Signed-off-by: Jan Kara <jack@suse.cz>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-02 10:28:52 -07:00
Linus Torvalds
1be44e234b xfs: update for 4.1-rc6
Changes in this update:
 o regression fix for new rename whiteout code
 o regression fixes for new superblock generic per-cpu counter code
 o fix for incorrect error return sign introduced in 3.17
 o metadata corruption fixes that need to go back to -stable kernels
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1.4.12 (GNU/Linux)
 
 iQIcBAABAgAGBQJVaO0JAAoJEK3oKUf0dfodd4UQANRdfXnUrpyQGhVS7HFoFoVt
 FIQ52pPGbMu72+DqHc+Q41uvgAPe65LFB2VUL6CUGCMExstF72F5+QonzppMgkMo
 unPER3eB8ya03SY+Kp+803ZGgzI2Nl2M6w8Kof730/RUk56PTGYIx4eLXd6iZSli
 RsYjw8JDbeue5OQo5FPmLCSQ/Kr5ZJXbgWVPyWkKg9aCcXLN5YSJIV3xcMTK9Q2I
 LqqODkyatnGc6YxGAKddS7Xzt1ntlZgbe5mndQw04a2g0Lf6emPH5r8b0UJXIu96
 advOBX0pEbad4FeFS6Mo5D+nNCaaNP4WzN7wgdb+BYNVw3ss4Ebam7+yY6Gexg6y
 bzZOEkk9saL4YeBDgyYICNu7kG4BRVKRQiiX220G6SFXM3nqbl7qBPb3kVFyDpcI
 RRuFJ0ZV0kFJ+3IQ4xVnIh6nootceRk/mvZaK5HhLhQLzklpZ8fj4HF3oBDUAnvN
 wNd+7GoZy7zldjCkbF4BP3GjUeW+b9ngrCNc+bFXi5cUbdECXAa2krjxyY+MlQF2
 veNVVcsoRdfeM0VjJh2/piGJxMWIlRqXdKzPKsfMWnlIaJ6YyslfbSq+2K7LxgGR
 Ho3Sjt0oUuPMZ9F/Mjj+XDqwmzgooUHXNyDBxhGXBNBPjApcRLcb2vQ2SrWEmeGJ
 vZmC2R1ZoGdBJg8a55BT
 =w5SP
 -----END PGP SIGNATURE-----

Merge tag 'xfs-for-linus-4.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs

Pull xfs fixes from Dave Chinner:
 "This is a little larger than I'd like late in the release cycle, but
  all the fixes are for regressions introduced in the 4.1-rc1 merge, or
  are needed back in -stable kernels fairly quickly as they are
  filesystem corruption or userspace visible correctness issues.

  Changes in this update:

   - regression fix for new rename whiteout code

   - regression fixes for new superblock generic per-cpu counter code

   - fix for incorrect error return sign introduced in 3.17

   - metadata corruption fixes that need to go back to -stable kernels"

* tag 'xfs-for-linus-4.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs:
  xfs: fix broken i_nlink accounting for whiteout tmpfile inode
  xfs: xfs_iozero can return positive errno
  xfs: xfs_attr_inactive leaves inconsistent attr fork state behind
  xfs: extent size hints can round up extents past MAXEXTLEN
  xfs: inode and free block counters need to use __percpu_counter_compare
  percpu_counter: batch size aware __percpu_counter_compare()
  xfs: use percpu_counter_read_positive for mp->m_icount
2015-05-29 16:45:45 -07:00
Linus Torvalds
6e49ba1bb1 ** NOW WITH TESTING! **
Two fixes which got lost in my recent distraction.  One is a weird
 cpumask function which needed to be rewritten, the other is a module
 bug which is cc:stable.
 
 Thanks,
 Rusty.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQIcBAABAgAGBQJVaBENAAoJENkgDmzRrbjxxL4QAJMFwo21VN8rwIsEJ2P/Yh4u
 YXxJtnbrSPZtyad8J4G6FGOOfM7ImkkADhGJE8MN05goIFmeORWduAiozBtZBfo3
 OVpeo0HIGTEMXq/QCxSQsDhP9MSeWV592vjhlqQJ2KhU9Gpstc/Ub9ArVWuY3FD3
 CFN6ciw+5DIhoc6jMI2P9XX7jpR4VOBu320j+3lQ1QZ1aEZIaPefWH+VYuIZXirq
 E6N4yKgTahKb1Clr0DS6EB2Z5g+upNzFf4WBHaChP5EklwatZkHAOvzfSLWcbShI
 ochGV5LBPcn7ruqOD5mR4LGkxfQSYPCKCKihmenD/EVoO/dshKOQREfsqRXNsh5X
 xk4yx/VCy68ubIjx7FIDL18qDvJrX82+Z2bYZbENvKrVinaQ7MWB+CokK0fNW0ai
 ZMP5s32vSUZMMIIE7+fS4n3BLUxOpLZC8S0wIac19jNKzCHVTuhnUolCHk11zQLk
 IIDHEJwzvWtPjKOyUyd7HG0bYeczwf8DZgHg+xom9BNbHbK3Jk5d1Sibjgf8eGg+
 O36XR8FYYvqHwqqrPKSSaWoLj578/IWyHZg/V4tQ2HWi189BVHk6Iw2knftsvvPw
 pBu2AdbRSLLD+X/pwrdmm+xgytjUIr1X/Qnwj/eE5MvB/vaVVwV0OjapU/Z6S+dL
 JrZGvbWcviyjpvGD+vG1
 =wuP+
 -----END PGP SIGNATURE-----

Merge tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

Pull fixes for cpumask and modules from Rusty Russell:
 "** NOW WITH TESTING! **

  Two fixes which got lost in my recent distraction.  One is a weird
  cpumask function which needed to be rewritten, the other is a module
  bug which is cc:stable"

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  cpumask_set_cpu_local_first => cpumask_local_spread, lament
  module: Call module notifier on failure after complete_formation()
2015-05-29 11:24:28 -07:00
Dave Chinner
80188b0d77 percpu_counter: batch size aware __percpu_counter_compare()
XFS uses non-stanard batch sizes for avoiding frequent global
counter updates on it's allocated inode counters, as they increment
or decrement in batches of 64 inodes. Hence the standard percpu
counter batch of 32 means that the counter is effectively a global
counter. Currently Xfs uses a batch size of 128 so that it doesn't
take the global lock on every single modification.

However, Xfs also needs to compare accurately against zero, which
means we need to use percpu_counter_compare(), and that has a
hard-coded batch size of 32, and hence will spuriously fail to
detect when it is supposed to use precise comparisons and hence
the accounting goes wrong.

Add __percpu_counter_compare() to take a custom batch size so we can
use it sanely in XFS and factor percpu_counter_compare() to use it.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-05-29 07:39:34 +10:00
Rusty Russell
f36963c9d3 cpumask_set_cpu_local_first => cpumask_local_spread, lament
da91309e0a (cpumask: Utility function to set n'th cpu...) created a
genuinely weird function.  I never saw it before, it went through DaveM.
(He only does this to make us other maintainers feel better about our own
mistakes.)

cpumask_set_cpu_local_first's purpose is say "I need to spread things
across N online cpus, choose the ones on this numa node first"; you call
it in a loop.

It can fail.  One of the two callers ignores this, the other aborts and
fails the device open.

It can fail in two ways: allocating the off-stack cpumask, or through a
convoluted codepath which AFAICT can only occur if cpu_online_mask
changes.  Which shouldn't happen, because if cpu_online_mask can change
while you call this, it could return a now-offline cpu anyway.

It contains a nonsensical test "!cpumask_of_node(numa_node)".  This was
drawn to my attention by Geert, who said this causes a warning on Sparc.
It sets a single bit in a cpumask instead of returning a cpu number,
because that's what the callers want.

It could be made more efficient by passing the previous cpu rather than
an index, but that would be more invasive to the callers.

Fixes: da91309e0a
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (then rebased)
Tested-by: Amir Vadai <amirv@mellanox.com>
Acked-by: Amir Vadai <amirv@mellanox.com>
Acked-by: David S. Miller <davem@davemloft.net>
2015-05-28 11:05:20 +09:30
Herbert Xu
07ee0722bf rhashtable: Add cap on number of elements in hash table
We currently have no limit on the number of elements in a hash table.
This is a problem because some users (tipc) set a ceiling on the
maximum table size and when that is reached the hash table may
degenerate.  Others may encounter OOM when growing and if we allow
insertions when that happens the hash table perofrmance may also
suffer.

This patch adds a new paramater insecure_max_entries which becomes
the cap on the table.  If unset it defaults to max_size * 2.  If
it is also zero it means that there is no cap on the number of
elements in the table.  However, the table will grow whenever the
utilisation hits 100% and if that growth fails, you will get ENOMEM
on insertion.

As allowing oversubscription is potentially dangerous, the name
contains the word insecure.

Note that the cap is not a hard limit.  This is done for performance
reasons as enforcing a hard limit will result in use of atomic ops
that are heavier than the ones we currently use.

The reasoning is that we're only guarding against a gross over-
subscription of the table, rather than a small breach of the limit.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-16 18:08:26 -04:00
Linus Torvalds
02f0f5721e Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RCU fix from Ingo Molnar:
 "An RCU Kconfig fix that eliminates an annoying interactive kconfig
  question for CONFIG_RCU_TORTURE_TEST_SLOW_INIT"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  rcu: Control grace-period delays directly from value
2015-05-06 10:26:37 -07:00
Joe Perches
01e76903f6 kasan: show gcc version requirements in Kconfig and Documentation
The documentation shows a need for gcc > 4.9.2, but it's really >=.  The
Kconfig entries don't show require versions so add them.  Correct a
latter/later typo too.  Also mention that gcc 5 required to catch out of
bounds accesses to global and stack variables.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-05-05 17:10:10 -07:00
Yury Norov
7d616e4ddb lib: delete lib/find_last_bit.c
The file lib/find_last_bit.c was no longer used and supposed to be
deleted by commit 8f6f19dd51 ("lib: move find_last_bit to
lib/find_next_bit.c") but that delete didn't happen.  This gets rid of
it.

Signed-off-by: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-05-05 17:10:10 -07:00
Linus Torvalds
d9cee5d4f6 Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto fixes from Herbert Xu:
 "This fixes a build problem with bcm63xx and yet another fix to the
  memzero_explicit function to ensure that the memset is not elided"

* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  hwrng: bcm63xx - Fix driver compilation
  lib: make memzero_explicit more robust against dead store elimination
2015-05-05 09:03:52 -07:00
Daniel Borkmann
7829fb09a2 lib: make memzero_explicit more robust against dead store elimination
In commit 0b053c9518 ("lib: memzero_explicit: use barrier instead
of OPTIMIZER_HIDE_VAR"), we made memzero_explicit() more robust in
case LTO would decide to inline memzero_explicit() and eventually
find out it could be elimiated as dead store.

While using barrier() works well for the case of gcc, recent efforts
from LLVMLinux people suggest to use llvm as an alternative to gcc,
and there, Stephan found in a simple stand-alone user space example
that llvm could nevertheless optimize and thus elimitate the memset().
A similar issue has been observed in the referenced llvm bug report,
which is regarded as not-a-bug.

Based on some experiments, icc is a bit special on its own, while it
doesn't seem to eliminate the memset(), it could do so with an own
implementation, and then result in similar findings as with llvm.

The fix in this patch now works for all three compilers (also tested
with more aggressive optimization levels). Arguably, in the current
kernel tree it's more of a theoretical issue, but imho, it's better
to be pedantic about it.

It's clearly visible with gcc/llvm though, with the below code: if we
would have used barrier() only here, llvm would have omitted clearing,
not so with barrier_data() variant:

  static inline void memzero_explicit(void *s, size_t count)
  {
    memset(s, 0, count);
    barrier_data(s);
  }

  int main(void)
  {
    char buff[20];
    memzero_explicit(buff, sizeof(buff));
    return 0;
  }

  $ gcc -O2 test.c
  $ gdb a.out
  (gdb) disassemble main
  Dump of assembler code for function main:
   0x0000000000400400  <+0>: lea   -0x28(%rsp),%rax
   0x0000000000400405  <+5>: movq  $0x0,-0x28(%rsp)
   0x000000000040040e <+14>: movq  $0x0,-0x20(%rsp)
   0x0000000000400417 <+23>: movl  $0x0,-0x18(%rsp)
   0x000000000040041f <+31>: xor   %eax,%eax
   0x0000000000400421 <+33>: retq
  End of assembler dump.

  $ clang -O2 test.c
  $ gdb a.out
  (gdb) disassemble main
  Dump of assembler code for function main:
   0x00000000004004f0  <+0>: xorps  %xmm0,%xmm0
   0x00000000004004f3  <+3>: movaps %xmm0,-0x18(%rsp)
   0x00000000004004f8  <+8>: movl   $0x0,-0x8(%rsp)
   0x0000000000400500 <+16>: lea    -0x18(%rsp),%rax
   0x0000000000400505 <+21>: xor    %eax,%eax
   0x0000000000400507 <+23>: retq
  End of assembler dump.

As gcc, clang, but also icc defines __GNUC__, it's sufficient to define
this in compiler-gcc.h only to be picked up. For a fallback or otherwise
unsupported compiler, we define it as a barrier. Similarly, for ecc which
does not support gcc inline asm.

Reference: https://llvm.org/bugs/show_bug.cgi?id=15495
Reported-by: Stephan Mueller <smueller@chronox.de>
Tested-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Stephan Mueller <smueller@chronox.de>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: mancha security <mancha1@zoho.com>
Cc: Mark Charlebois <charlebm@gmail.com>
Cc: Behan Webster <behanw@converseincode.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-05-04 17:49:51 +08:00
Linus Torvalds
2decb2682f Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:

 1) mlx4 doesn't check fully for supported valid RSS hash function, fix
    from Amir Vadai

 2) Off by one in ibmveth_change_mtu(), from David Gibson

 3) Prevent altera chip from reporting false error interrupts in some
    circumstances, from Chee Nouk Phoon

 4) Get rid of that stupid endless loop trying to allocate a FIN packet
    in TCP, and in the process kill deadlocks.  From Eric Dumazet

 5) Fix get_rps_cpus() crash due to wrong invalid-cpu value, also from
    Eric Dumazet

 6) Fix two bugs in async rhashtable resizing, from Thomas Graf

 7) Fix topology server listener socket namespace bug in TIPC, from Ying
    Xue

 8) Add some missing HAS_DMA kconfig dependencies, from Geert
    Uytterhoeven

 9) bgmac driver intends to force re-polling but does so by returning
    the wrong value from it's ->poll() handler.  Fix from Rafał Miłecki

10) When the creater of an rhashtable configures a max size for it,
    don't bark in the logs and drop insertions when that is exceeded.
    Fix from Johannes Berg

11) Recover from out of order packets in ppp mppe properly, from Sylvain
    Rochet

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (41 commits)
  bnx2x: really disable TPA if 'disable_tpa' option is set
  net:treewide: Fix typo in drivers/net
  net/mlx4_en: Prevent setting invalid RSS hash function
  mdio-mux-gpio: use new gpiod_get_array and gpiod_put_array functions
  netfilter; Add some missing default cases to switch statements in nft_reject.
  ppp: mppe: discard late packet in stateless mode
  ppp: mppe: sanity error path rework
  net/bonding: Make DRV macros private
  net: rfs: fix crash in get_rps_cpus()
  altera tse: add support for fixed-links.
  pxa168: fix double deallocation of managed resources
  net: fix crash in build_skb()
  net: eth: altera: Resolve false errors from MSGDMA to TSE
  ehea: Fix memory hook reference counting crashes
  net/tg3: Release IRQs on permanent error
  net: mdio-gpio: support access that may sleep
  inet: fix possible panic in reqsk_queue_unlink()
  rhashtable: don't attempt to grow when at max_size
  bgmac: fix requests for extra polling calls from NAPI
  tcp: avoid looping in tcp_send_fin()
  ...
2015-04-27 14:05:19 -07:00
Linus Torvalds
474095e46c md updates for 4.1
Highlights:
 
 - "experimental" code for managing md/raid1 across a cluster using
   DLM.  Code is not ready for general use and triggers a WARNING if used.
   However it is looking good and mostly done and having in mainline
   will help co-ordinate development.
 - RAID5/6 can now batch multiple (4K wide) stripe_heads so as to
   handle a full (chunk wide) stripe as a single unit.
 - RAID6 can now perform read-modify-write cycles which should
   help performance on larger arrays: 6 or more devices.
 - RAID5/6 stripe cache now grows and shrinks dynamically.  The value
   set is used as a minimum.
 - Resync is now allowed to go a little faster than the 'mininum' when
   there is competing IO.  How much faster depends on the speed of the
   devices, so the effective minimum should scale with device speed to
   some extent.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2
 
 iQIVAwUAVTbIxDnsnt1WYoG5AQIgAA//Z9FlEpkHcJJ75WGjrXgGJPyNTfEZOkoz
 jnD8PpBY2Afp341vMatd0XKErdEAhuPQmJMAa+tbxht6pk77X3fSzXghGA8FEafg
 yazn5pfBt6NXmepV4vhl/+LNYuWRxxLSA9EDm7wEg+tiO0UEts+a0w2TSXzcT1w+
 30Yi1EjAlTaJ5yjlBHUOtTXWE43D6RKnUr6FMy2dRlnzlFyDlezRMChWo9v6OkQF
 YqJ20FcvmJdLHY/6Yif3jvpm7eQecMqdCZENTvW/mJI86zqf6E+ToCYS1VNjfDnK
 ud61iU9eshu4WtNWBG6KLuHBD0grO1NaEL7/S16w1KdNJMhYgiK8WussvIAJEesA
 5SlETM7Y/1XFq8puwlAq2/tuPfhZ+TFxnAwce/C3hMTDcYAACnS/R6INFQXqGvy3
 nX1NLogrCycX8oqxv3jTFKLVqIVwlkSlHcUGzIWjcfCF37StcXFKI5q862agyg2+
 NNocFMuXhPPM1YcB9JJSo2nCsor4e9tTdVEZlFm2B3cc8LJ9BLWUMSoi1h7VK/1g
 P7psnPIjz7/cdI2TZTFjGTZ0Kvhx/NTYp41AZealDNxeGWUNM+5xGZnUF8QRBc/E
 0dGHtEAah834BDQFvNnJtuuh/s+KwbvswjNP+njoBsHjIQIvngDABpOwpIkdqF6r
 diQ2gUPnHN0=
 =OHG6
 -----END PGP SIGNATURE-----

Merge tag 'md/4.1' of git://neil.brown.name/md

Pull md updates from Neil Brown:
 "More updates that usual this time.  A few have performance impacts
  which hould mostly be positive, but RAID5 (in particular) can be very
  work-load ensitive...  We'll have to wait and see.

  Highlights:

   - "experimental" code for managing md/raid1 across a cluster using
     DLM.  Code is not ready for general use and triggers a WARNING if
     used.  However it is looking good and mostly done and having in
     mainline will help co-ordinate development.

   - RAID5/6 can now batch multiple (4K wide) stripe_heads so as to
     handle a full (chunk wide) stripe as a single unit.

   - RAID6 can now perform read-modify-write cycles which should help
     performance on larger arrays: 6 or more devices.

   - RAID5/6 stripe cache now grows and shrinks dynamically.  The value
     set is used as a minimum.

   - Resync is now allowed to go a little faster than the 'mininum' when
     there is competing IO.  How much faster depends on the speed of the
     devices, so the effective minimum should scale with device speed to
     some extent"

* tag 'md/4.1' of git://neil.brown.name/md: (58 commits)
  md/raid5: don't do chunk aligned read on degraded array.
  md/raid5: allow the stripe_cache to grow and shrink.
  md/raid5: change ->inactive_blocked to a bit-flag.
  md/raid5: move max_nr_stripes management into grow_one_stripe and drop_one_stripe
  md/raid5: pass gfp_t arg to grow_one_stripe()
  md/raid5: introduce configuration option rmw_level
  md/raid5: activate raid6 rmw feature
  md/raid6 algorithms: xor_syndrome() for SSE2
  md/raid6 algorithms: xor_syndrome() for generic int
  md/raid6 algorithms: improve test program
  md/raid6 algorithms: delta syndrome functions
  raid5: handle expansion/resync case with stripe batching
  raid5: handle io error of batch list
  RAID5: batch adjacent full stripe write
  raid5: track overwrite disk count
  raid5: add a new flag to track if a stripe can be batched
  raid5: use flex_array for scribble data
  md raid0: access mddev->queue (request queue member) conditionally because it is not set when accessed from dm-raid
  md: allow resync to go faster when there is competing IO.
  md: remove 'go_faster' option from ->sync_request()
  ...
2015-04-24 09:28:01 -07:00
Thomas Graf
a87b9ebf17 rhashtable: Do not schedule more than one rehash if we can't grow further
The current code currently only stops inserting rehashes into the
chain when no resizes are currently scheduled. As long as resizes
are scheduled and while inserting above the utilization watermark,
more and more rehashes will be scheduled.

This lead to a perfect DoS storm with thousands of rehashes
scheduled which lead to thousands of spinlocks to be taken
sequentially.

Instead, only allow either a series of resizes or a single rehash.
Drop any further rehashes and return -EBUSY.

Fixes: ccd57b1bd3 ("rhashtable: Add immediate rehash during insertion")
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-22 14:17:22 -04:00
Thomas Graf
e2307ed6cb rhashtable: Schedule async resize when sync realloc fails
When rhashtable_insert_rehash() fails with ENOMEM, this indicates that
we can't allocate the necessary memory in the current context but the
limits as set by the user would still allow to grow.

Thus attempt an async resize in the background where we can allocate
using GFP_KERNEL which is more likely to succeed. The insertion itself
will still fail to indicate pressure.

This fixes a bug where the table would never continue growing once the
utilization is above 100%.

Fixes: ccd57b1bd3 ("rhashtable: Add immediate rehash during insertion")
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-22 14:17:22 -04:00
Linus Torvalds
db4fd9c5d0 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc
Pull sparc fixes from David Miller:

 1) ldc_alloc_exp_dring() can be called from softints, so use
    GFP_ATOMIC.  From Sowmini Varadhan.

 2) Some minor warning/build fixups for the new iommu-common code on
    certain archs and with certain debug options enabled.  Also from
    Sowmini Varadhan.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
  sparc: Use GFP_ATOMIC in ldc_alloc_exp_dring() as it can be called in softirq context
  sparc64: Use M7 PMC write on all chips T4 and onward.
  iommu-common: rename iommu_pool_hash to iommu_hash_common
  iommu-common: fix x86_64 compiler warnings
2015-04-21 23:21:34 -07:00
Markus Stockhausen
a582564b24 md/raid6 algorithms: xor_syndrome() for SSE2
The second and (last) optimized XOR syndrome calculation. This version
supports right and left side optimization. All CPUs with architecture
older than Haswell will benefit from it.

It should be noted that SSE2 movntdq kills performance for memory areas
that are read and written simultaneously in chunks smaller than cache
line size. So use movdqa instead for P/Q writes in sse21 and sse22 XOR
functions.

Signed-off-by: Markus Stockhausen <stockhausen@collogia.de>
Signed-off-by: NeilBrown <neilb@suse.de>
2015-04-22 08:00:42 +10:00
Markus Stockhausen
9a5ce91d05 md/raid6 algorithms: xor_syndrome() for generic int
Start the algorithms with the very basic one. It is left and right
optimized. That means we can avoid all calculations for unneeded pages
above the right stop offset. For pages below the left start offset we
still need the syndrome multiplication but without reading data pages.

Signed-off-by: Markus Stockhausen <stockhausen@collogia.de>
Signed-off-by: NeilBrown <neilb@suse.de>
2015-04-22 08:00:42 +10:00
Markus Stockhausen
7e92e1d762 md/raid6 algorithms: improve test program
It is always helpful to have a test tool in place if we implement
new data critical algorithms. So add some test routines to the raid6
checker that can prove if the new xor_syndrome() works as expected.

Run through all permutations of start/stop pages per algorithm and
simulate a xor_syndrome() assisted rmw run. After each rmw check if
the recovery algorithm still confirms that the stripe is fine.

Signed-off-by: Markus Stockhausen <stockhausen@collogia.de>
Signed-off-by: NeilBrown <neilb@suse.de>
2015-04-22 08:00:42 +10:00
Markus Stockhausen
fe5cbc6e06 md/raid6 algorithms: delta syndrome functions
v3: s-o-b comment, explanation of performance and descision for
the start/stop implementation

Implementing rmw functionality for RAID6 requires optimized syndrome
calculation. Up to now we can only generate a complete syndrome. The
target P/Q pages are always overwritten. With this patch we provide
a framework for inplace P/Q modification. In the first place simply
fill those functions with NULL values.

xor_syndrome() has two additional parameters: start & stop. These
will indicate the first and last page that are changing during a
rmw run. That makes it possible to avoid several unneccessary loops
and speed up calculation. The caller needs to implement the following
logic to make the functions work.

1) xor_syndrome(disks, start, stop, ...): "Remove" all data of source
blocks inside P/Q between (and including) start and end.

2) modify any block with start <= block <= stop

3) xor_syndrome(disks, start, stop, ...): "Reinsert" all data of
source blocks into P/Q between (and including) start and end.

Pages between start and stop that won't be changed should be filled
with a pointer to the kernel zero page. The reasons for not taking NULL
pages are:

1) Algorithms cross the whole source data line by line. Thus avoid
additional branches.

2) Having a NULL page avoids calculating the XOR P parity but still
need calulation steps for the Q parity. Depending on the algorithm
unrolling that might be only a difference of 2 instructions per loop.

The benchmark numbers of the gen_syndrome() functions are displayed in
the kernel log. Do the same for the xor_syndrome() functions. This
will help to analyze performance problems and give an rough estimate
how well the algorithm works. The choice of the fastest algorithm will
still depend on the gen_syndrome() performance.

With the start/stop page implementation the speed can vary a lot in real
life. E.g. a change of page 0 & page 15 on a stripe will be harder to
compute than the case where page 0 & page 1 are XOR candidates. To be not
to enthusiatic about the expected speeds we will run a worse case test
that simulates a change on the upper half of the stripe. So we do:

1) calculation of P/Q for the upper pages

2) continuation of Q for the lower (empty) pages

Signed-off-by: Markus Stockhausen <stockhausen@collogia.de>
Signed-off-by: NeilBrown <neilb@suse.de>
2015-04-22 08:00:41 +10:00
Linus Torvalds
1fc149933f Char/Misc driver patches for 4.1-rc1
Here's the big char/misc driver patchset for 4.1-rc1.
 
 Lots of different driver subsystem updates here, nothing major, full
 details are in the shortlog below.
 
 All of this has been in linux-next for a while.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2
 
 iEYEABECAAYFAlU2IMEACgkQMUfUDdst+yloDQCfbyIRL23WVAn9ckQse/y8gbjB
 OT4AoKTJbwndDP9Kb/lrj2tjd9QjNVrC
 =xhen
 -----END PGP SIGNATURE-----

Merge tag 'char-misc-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char/misc driver updates from Greg KH:
 "Here's the big char/misc driver patchset for 4.1-rc1.

  Lots of different driver subsystem updates here, nothing major, full
  details are in the shortlog.

  All of this has been in linux-next for a while"

* tag 'char-misc-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (133 commits)
  mei: trace: remove unused TRACE_SYSTEM_STRING
  DTS: ARM: OMAP3-N900: Add lis3lv02d support
  Documentation: DT: lis302: update wakeup binding
  lis3lv02d: DT: add wakeup unit 2 and wakeup threshold
  lis3lv02d: DT: use s32 to support negative values
  Drivers: hv: hv_balloon: correctly handle num_pages>INT_MAX case
  Drivers: hv: hv_balloon: correctly handle val.freeram<num_pages case
  mei: replace check for connection instead of transitioning
  mei: use mei_cl_is_connected consistently
  mei: fix mei_poll operation
  hv_vmbus: Add gradually increased delay for retries in vmbus_post_msg()
  Drivers: hv: hv_balloon: survive ballooning request with num_pages=0
  Drivers: hv: hv_balloon: eliminate jumps in piecewiese linear floor function
  Drivers: hv: hv_balloon: do not online pages in offline blocks
  hv: remove the per-channel workqueue
  hv: don't schedule new works in vmbus_onoffer()/vmbus_onoffer_rescind()
  hv: run non-blocking message handlers in the dispatch tasklet
  coresight: moving to new "hwtracing" directory
  coresight-tmc: Adding a status interface to sysfs
  coresight: remove the unnecessary configuration coresight-default-sink
  ...
2015-04-21 09:42:58 -07:00
Sowmini Varadhan
7b3372d4c2 iommu-common: rename iommu_pool_hash to iommu_hash_common
When CONFIG_DEBUG_FORCE_WEAK_PER_CPU is set, the DEFINE_PER_CPU_SECTION
macro will define an extern __pcpu_unique_##name variable that could
conflict with the same definition in powerpc at this time. Avoid that
conflict by renaming iommu_pool_hash in iommu-common.c

Thanks to Guenter Roeck for catching this, and helping to test the fix.

Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-20 14:09:55 -04:00
Sowmini Varadhan
b0cc836d30 iommu-common: fix x86_64 compiler warnings
Declare iommu_large_alloc as static. Remove extern definition  for
iommu_tbl_pool_init().

Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-20 14:09:55 -04:00
Linus Torvalds
6496edfce9 This is the final removal (after several years!) of the obsolete cpus_*
functions, prompted by their mis-use in staging.
 
 With these function removed, all cpu functions should only iterate to
 nr_cpu_ids, so we finally only allocate that many bits when cpumasks
 are allocated offstack.
 
 Thanks,
 Rusty.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQIcBAABAgAGBQJVNPMuAAoJENkgDmzRrbjx7ZIP/j65e6xs1jEyXR3WOYSdTU1x
 bMo6JcII6O1oEZLgyKXgx9KiBg6uIIDta1NG/H/XIe354dwfHVsHvj5HHHQR5Xof
 iRrjLOaHj4XglI3hvsk0eEEl3/OBBLgyo9bUwDvMF1fmr/9tW4caMs3Op6n7Evzm
 YIvoAyeJ0A8BfEtOU5lXhcVIGmnHtSw0x6mdGXpXIBmWYQPCtdQP868s4lnl44w0
 bSNpAYdzEqg64Ph3SK0prgWPrn5+5EiaAhV7HZzENZ5+o0DAdIXWq/W7uHyCWPKH
 536cJDojec+nSUQkPYngngGprxrKO02aBcMw/3JGJ0tdCDj8yw3XAyVAFzz4hmMb
 Lkmyv4QHHIILLvJ4ZRH5KHWCjjVBg41LNCs2H3HnoxFACdm0lZYKHsUAh2ucBVtU
 Wb/eHmLxOG43UIkpX4yrhy3SfE1ZdnOVzEzOzPXtr51t8ojqk+bLFe/hJ6EkzrQX
 X+90qHfBq+PMJlAnc3zdXHjxoJrL6KPWVwVvFrNeibgEKtVvy/BiwZkS6QceC1Ea
 TatOYA5r6awFVHHQCooN1DGAxN5Juvu2SmdnTUA9ymsCNDghj1YUoAKRNP81u8Sa
 pe3hco/63iCuPna+vlwNDU6SgsaMk9m0p+1n1BiDIfVJIkWYCNeG+u2gQkzbDKlQ
 AJuKKQv1QuZiF0ylZ0wq
 =VAgA
 -----END PGP SIGNATURE-----

Merge tag 'cpumask-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

Pull final removal of deprecated cpus_* cpumask functions from Rusty Russell:
 "This is the final removal (after several years!) of the obsolete
  cpus_* functions, prompted by their mis-use in staging.

  With these function removed, all cpu functions should only iterate to
  nr_cpu_ids, so we finally only allocate that many bits when cpumasks
  are allocated offstack"

* tag 'cpumask-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (25 commits)
  cpumask: remove __first_cpu / __next_cpu
  cpumask: resurrect CPU_MASK_CPU0
  linux/cpumask.h: add typechecking to cpumask_test_cpu
  cpumask: only allocate nr_cpumask_bits.
  Fix weird uses of num_online_cpus().
  cpumask: remove deprecated functions.
  mips: fix obsolete cpumask_of_cpu usage.
  x86: fix more deprecated cpu function usage.
  ia64: remove deprecated cpus_ usage.
  powerpc: fix deprecated CPU_MASK_CPU0 usage.
  CPU_MASK_ALL/CPU_MASK_NONE: remove from deprecated region.
  staging/lustre/o2iblnd: Don't use cpus_weight
  staging/lustre/libcfs: replace deprecated cpus_ calls with cpumask_
  staging/lustre/ptlrpc: Do not use deprecated cpus_* functions
  blackfin: fix up obsolete cpu function usage.
  parisc: fix up obsolete cpu function usage.
  tile: fix up obsolete cpu function usage.
  arm64: fix up obsolete cpu function usage.
  mips: fix up obsolete cpu function usage.
  x86: fix up obsolete cpu function usage.
  ...
2015-04-20 10:19:03 -07:00
Linus Torvalds
17974c054d hexdump: avoid warning in test function
The test_data_1_le[] array is a const array of const char *.  To avoid
dropping any const information, we need to use "const char * const *",
not just "const char **".

I'm not sure why the different test arrays end up having different
const'ness, but let's make the pointer we use to traverse them as const
as possible, since we modify neither the array of pointers _or_ the
pointers we find in the array.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-19 13:48:40 -07:00
Rusty Russell
e4afa120c9 cpumask: remove __first_cpu / __next_cpu
They were for use by the deprecated first_cpu() and next_cpu() wrappers,
but sparc used them directly.

They're now replaced by cpumask_first / cpumask_next.  And __next_cpu_nr
is completely obsolete.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: David S. Miller <davem@davemloft.net>
2015-04-19 14:35:32 +09:30
Sowmini Varadhan
2f0c0fdc08 iommu-common: Fix PARISC compile-time warnings
Fixes warnings due to
- no DMA_ERROR_CODE on PARISC,
- sizeof (unsigned long) == 4 bytes on PARISC.

Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-18 12:34:50 -07:00
Sowmini Varadhan
ff7d37a502 Break up monolithic iommu table/lock into finer graularity pools and lock
Investigation of multithreaded iperf experiments on an ethernet
interface show the iommu->lock as the hottest lock identified by
lockstat, with something of the order of  21M contentions out of
27M acquisitions, and an average wait time of 26 us for the lock.
This is not efficient. A more scalable design is to follow the ppc
model, where the iommu_map_table has multiple pools, each stretching
over a segment of the map, and with a separate lock for each pool.
This model allows for better parallelization of the iommu map search.

This patch adds the iommu range alloc/free function infrastructure.

Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-18 12:32:59 -07:00
David S. Miller
c12f048ffd sparc: Revert generic IOMMU allocator.
I applied the wrong version of this patch series, V4 instead
of V10, due to a patchwork bundling snafu.

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-18 12:31:25 -07:00
Ingo Molnar
cb0f3f320d Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/urgent
Pull RCU fix from Paul E. McKenney:

 "This series contains a single change that fixes Kconfig asking pointless
  questions."

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-18 14:49:41 +02:00
Linus Torvalds
e2fdae7e7c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc
Pull sparc updates from David Miller:
 "The PowerPC folks have a really nice scalable IOMMU pool allocator
  that we wanted to make use of for sparc.  So here we have a series
  that abstracts out their code into a common layer that anyone can make
  use of.

  Sparc is converted, and the PowerPC folks have reviewed and ACK'd this
  series and plan to convert PowerPC over as well"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
  iommu-common: Fix PARISC compile-time warnings
  sparc: Make LDC use common iommu poll management functions
  sparc: Make sparc64 use scalable lib/iommu-common.c functions
  sparc: Break up monolithic iommu table/lock into finer graularity pools and lock
2015-04-17 16:19:26 -04:00
Sowmini Varadhan
cb97201cb0 iommu-common: Fix PARISC compile-time warnings
Fixes warnings due to
- no DMA_ERROR_CODE on PARISC,
- sizeof (unsigned long) == 4 bytes on PARISC.

Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-17 15:24:36 -04:00
Linus Torvalds
54e514b91b Merge branch 'akpm' (patches from Andrew)
Merge third patchbomb from Andrew Morton:

 - various misc things

 - a couple of lib/ optimisations

 - provide DIV_ROUND_CLOSEST_ULL()

 - checkpatch updates

 - rtc tree

 - befs, nilfs2, hfs, hfsplus, fatfs, adfs, affs, bfs

 - ptrace fixes

 - fork() fixes

 - seccomp cleanups

 - more mmap_sem hold time reductions from Davidlohr

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (138 commits)
  proc: show locks in /proc/pid/fdinfo/X
  docs: add missing and new /proc/PID/status file entries, fix typos
  drivers/rtc/rtc-at91rm9200.c: make IO endian agnostic
  Documentation/spi/spidev_test.c: fix warning
  drivers/rtc/rtc-s5m.c: allow usage on device type different than main MFD type
  .gitignore: ignore *.tar
  MAINTAINERS: add Mediatek SoC mailing list
  tomoyo: reduce mmap_sem hold for mm->exe_file
  powerpc/oprofile: reduce mmap_sem hold for exe_file
  oprofile: reduce mmap_sem hold for mm->exe_file
  mips: ip32: add platform data hooks to use DS1685 driver
  lib/Kconfig: fix up HAVE_ARCH_BITREVERSE help text
  x86: switch to using asm-generic for seccomp.h
  sparc: switch to using asm-generic for seccomp.h
  powerpc: switch to using asm-generic for seccomp.h
  parisc: switch to using asm-generic for seccomp.h
  mips: switch to using asm-generic for seccomp.h
  microblaze: use asm-generic for seccomp.h
  arm: use asm-generic for seccomp.h
  seccomp: allow COMPAT sigreturn overrides
  ...
2015-04-17 09:04:38 -04:00
Andrew Morton
9e522c0d28 lib/Kconfig: fix up HAVE_ARCH_BITREVERSE help text
Cc: Yalin Wang <yalin.wang@sonymobile.com>
Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17 09:04:10 -04:00
Sergey Senozhatsky
534b483a86 cpumask: don't perform while loop in cpumask_next_and()
cpumask_next_and() is looking for cpumask_next() in src1 in a loop and
tests if found cpu is also present in src2. remove that loop, perform
cpumask_and() of src1 and src2 first and use that new mask to find
cpumask_next().

Apart from removing while loop, ./bloat-o-meter on x86_64 shows
add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-8 (-8)
function                                     old     new   delta
cpumask_next_and                              62      54      -8

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Amir Vadai <amirv@mellanox.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17 09:04:08 -04:00
Yury Norov
2afe27c718 lib/bitmap.c: bitmap_[empty,full]: remove code duplication
bitmap_empty() has its own implementation.  But it's clearly as simple as:

	find_first_bit(src, nbits) == nbits

The same is true for 'bitmap_full'.

Signed-off-by: Yury Norov <yury.norov@gmail.com>
Cc: George Spelvin <linux@horizon.com>
Cc: Alexey Klimov <klimov.linux@gmail.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17 09:03:56 -04:00
Rasmus Villemoes
675cf53c1d lib/vsprintf.c: improve put_dec_trunc8 slightly
I hadn't had enough coffee when I wrote this. Currently, the final
increment of buf depends on the value loaded from the table, and
causes gcc to emit a cmov immediately before the return. It is smarter
to let it depend on r, since the increment can then be computed in
parallel with the final load/store pair. It also shaves 16 bytes of
.text.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Tejun Heo <tj@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17 09:03:55 -04:00
Sebastian Ott
a7a2c02a40 lib/dma-debug: fix bucket_find_contain()
bucket_find_contain() will search the bucket list for a dma_debug_entry.
When the entry isn't found it needs to search other buckets too, since
only the start address of a dma range is hashed (which might be in a
different bucket).

A copy of the dma_debug_entry is used to get the previous hash bucket
but when its list is searched the original dma_debug_entry is to be used
not its modified copy.

This fixes false "device driver tries to sync DMA memory it has not allocated"
warnings.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Horia Geanta <horia.geanta@freescale.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17 09:03:54 -04:00
Rasmus Villemoes
7c43d9a30c lib/vsprintf.c: even faster binary to decimal conversion
The most expensive part of decimal conversion is the divisions by 10
(albeit done using reciprocal multiplication with appropriately chosen
constants).  I decided to see if one could eliminate around half of
these multiplications by emitting two digits at a time, at the cost of a
200 byte lookup table, and it does indeed seem like there is something
to be gained, especially on 64 bits.  Microbenchmarking shows
improvements ranging from -50% (for numbers uniformly distributed in [0,
2^64-1]) to -25% (for numbers heavily biased toward the smaller end, a
more realistic distribution).

On a larger scale, perf shows that top, one of the big consumers of /proc
data, uses 0.5-1.0% fewer cpu cycles.

I had to jump through some hoops to get the 32 bit code to compile and run
on my 64 bit machine, so I'm not sure how relevant these numbers are, but
just for comparison the microbenchmark showed improvements between -30%
and -10%.

The bloat-o-meter costs are around 150 bytes (the generated code is a
little smaller, so it's not the full 200 bytes) on both 32 and 64 bit.
I'm aware that extra cache misses won't show up in a microbenchmark as
used above, but on the other hand decimal conversions often happen in bulk
(for example in the case of top).

I have of course tested that the new code generates the same output as the
old, for both the first and last 1e10 numbers in [0,2^64-1] and 4e9
'random' numbers in-between.

Test and verification code on github: https://github.com/Villemoes/dec.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Tested-by: Jeff Epler <jepler@unpythonic.net>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17 09:03:54 -04:00
Yury Norov
840620a159 lib: rename lib/find_next_bit.c to lib/find_bit.c
This file contains implementation for all find_*_bit{,_le}
So giving it more generic name looks reasonable.

Signed-off-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: George Spelvin <linux@horizon.com>
Cc: Alexey Klimov <klimov.linux@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Daniel Borkmann <dborkman@redhat.com>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Thomas Graf <tgraf@suug.ch>
Cc: Valentin Rothberg <valentinrothberg@gmail.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17 09:03:54 -04:00
Yury Norov
8f6f19dd51 lib: move find_last_bit to lib/find_next_bit.c
Currently all 'find_*_bit' family is located in lib/find_next_bit.c,
except 'find_last_bit', which is in lib/find_last_bit.c. It seems,
there's no major benefit to have it separated.

Signed-off-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: George Spelvin <linux@horizon.com>
Cc: Alexey Klimov <klimov.linux@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Daniel Borkmann <dborkman@redhat.com>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Thomas Graf <tgraf@suug.ch>
Cc: Valentin Rothberg <valentinrothberg@gmail.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17 09:03:54 -04:00
Yury Norov
2c57a0e233 lib: find_*_bit reimplementation
This patchset does rework to find_bit function family to achieve better
performance, and decrease size of text.  All rework is done in patch 1.
Patches 2 and 3 are about code moving and renaming.

It was boot-tested on x86_64 and MIPS (big-endian) machines.
Performance tests were ran on userspace with code like this:

	/* addr[] is filled from /dev/urandom */
	start = clock();
	while (ret < nbits)
		ret = find_next_bit(addr, nbits, ret + 1);

	end = clock();
	printf("%ld\t", (unsigned long) end - start);

On Intel(R) Core(TM) i7-3770 CPU @ 3.40GHz measurements are: (for
find_next_bit, nbits is 8M, for find_first_bit - 80K)

	find_next_bit:		find_first_bit:
	new	current		new	current
	26932	43151		14777	14925
	26947	43182		14521	15423
	26507	43824		15053	14705
	27329	43759		14473	14777
	26895	43367		14847	15023
	26990	43693		15103	15163
	26775	43299		15067	15232
	27282	42752		14544	15121
	27504	43088		14644	14858
	26761	43856		14699	15193
	26692	43075		14781	14681
	27137	42969		14451	15061
	...			...

find_next_bit performance gain is 35-40%;
find_first_bit - no measurable difference.

On ARM machine, there is arch-specific implementation for find_bit.

Thanks a lot to George Spelvin and Rasmus Villemoes for hints and
helpful discussions.

This patch (of 3):

New implementations takes less space in source file (see diffstat) and in
object.  For me it's 710 vs 453 bytes of text.  It also shows better
performance.

find_last_bit description fixed due to obvious typo.

[akpm@linux-foundation.org: include linux/bitmap.h, per Rasmus]
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: George Spelvin <linux@horizon.com>
Cc: Alexey Klimov <klimov.linux@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Daniel Borkmann <dborkman@redhat.com>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Thomas Graf <tgraf@suug.ch>
Cc: Valentin Rothberg <valentinrothberg@gmail.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17 09:03:53 -04:00
Linus Torvalds
7d69cff26c SCSI misc on 20150416
This is the usual grab bag of driver updates (lpfc, qla2xxx, storvsc, aacraid,
 ipr) plus an assortment of minor updates.  There's also a major update to
 aic1542 which moves the driver into this millenium.
 
 Signed-off-by: James Bottomley <JBottomley@Odin.com>
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2
 
 iQEcBAABAgAGBQJVL/DEAAoJEDeqqVYsXL0MOwgIALPlgI0aMAtX5wLxzPMLB/2j
 fhNlsB9XZ6TeYIqE7syOY7geVJqsbACMGmDhGHs5Gt6jkTnwix/G49x3T1PXBODZ
 frz8GgNB6iGSqfCp+YbhJkTNHdudDIy2LrQ92EzNMb2+x0v6KTYTSq2dekgrC1zK
 8GUZ9bEzuxEGaBx9TK/Sy6H8QpvMtqqJig2eCL189U3JMMU3okWtSGya708u5Whh
 knbUgraMxFWNs+oHJHFclVYvekP+61i/TVyacQEM4KLDsmlxsLn49eRdiGMY6rpX
 LgDIvMjggQhbY2WcCXzetF7tsFFl0joJp1wFK1fUn9YN5e+J3MRWYVBDt8FMPX8=
 =OBny
 -----END PGP SIGNATURE-----

Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

Pull SCSI updates from James Bottomley:
 "This is the usual grab bag of driver updates (lpfc, qla2xxx, storvsc,
  aacraid, ipr) plus an assortment of minor updates.  There's also a
  major update to aic1542 which moves the driver into this millenium"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (106 commits)
  change SCSI Maintainer email
  sd, mmc, virtio_blk, string_helpers: fix block size units
  ufs: add support to allow non standard behaviours (quirks)
  ufs-qcom: save controller revision info in internal structure
  qla2xxx: Update driver version to 8.07.00.18-k
  qla2xxx: Restore physical port WWPN only, when port down detected for FA-WWPN port.
  qla2xxx: Fix virtual port configuration, when switch port is disabled/enabled.
  qla2xxx: Prevent multiple firmware dump collection for ISP27XX.
  qla2xxx: Disable Interrupt handshake for ISP27XX.
  qla2xxx: Add debugging info for MBX timeout.
  qla2xxx: Add serdes read/write support for ISP27XX
  qla2xxx: Add udev notification to save fw dump for ISP27XX
  qla2xxx: Add message for sucessful FW dump collected for ISP27XX.
  qla2xxx: Add support to load firmware from file for ISP 26XX/27XX.
  qla2xxx: Fix beacon blink for ISP27XX.
  qla2xxx: Increase the wait time for firmware to be ready for P3P.
  qla2xxx: Fix crash due to wrong casting of reg for ISP27XX.
  qla2xxx: Fix warnings reported by static checker.
  lpfc: Update version to 10.5.0.0 for upstream patch set
  lpfc: Update copyright to 2015
  ...
2015-04-16 19:02:04 -04:00
Sowmini Varadhan
10b88a4b17 sparc: Break up monolithic iommu table/lock into finer graularity pools and lock
Investigation of multithreaded iperf experiments on an ethernet
interface show the iommu->lock as the hottest lock identified by
lockstat, with something of the order of  21M contentions out of
27M acquisitions, and an average wait time of 26 us for the lock.
This is not efficient. A more scalable design is to follow the ppc
model, where the iommu_table has multiple pools, each stretching
over a segment of the map, and with a separate lock for each pool.
This model allows for better parallelization of the iommu map search.

This patch adds the iommu range alloc/free function infrastructure.

Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-16 12:44:55 -07:00
Linus Torvalds
eea3a00264 Merge branch 'akpm' (patches from Andrew)
Merge second patchbomb from Andrew Morton:

 - the rest of MM

 - various misc bits

 - add ability to run /sbin/reboot at reboot time

 - printk/vsprintf changes

 - fiddle with seq_printf() return value

* akpm: (114 commits)
  parisc: remove use of seq_printf return value
  lru_cache: remove use of seq_printf return value
  tracing: remove use of seq_printf return value
  cgroup: remove use of seq_printf return value
  proc: remove use of seq_printf return value
  s390: remove use of seq_printf return value
  cris fasttimer: remove use of seq_printf return value
  cris: remove use of seq_printf return value
  openrisc: remove use of seq_printf return value
  ARM: plat-pxa: remove use of seq_printf return value
  nios2: cpuinfo: remove use of seq_printf return value
  microblaze: mb: remove use of seq_printf return value
  ipc: remove use of seq_printf return value
  rtc: remove use of seq_printf return value
  power: wakeup: remove use of seq_printf return value
  x86: mtrr: if: remove use of seq_printf return value
  linux/bitmap.h: improve BITMAP_{LAST,FIRST}_WORD_MASK
  MAINTAINERS: CREDITS: remove Stefano Brivio from B43
  .mailmap: add Ricardo Ribalda
  CREDITS: add Ricardo Ribalda Delgado
  ...
2015-04-15 16:39:15 -07:00
Joe Perches
d50f8f8d91 lru_cache: remove use of seq_printf return value
The seq_printf return value, because it's frequently misused,
will eventually be converted to void.

See: commit 1f33c41c03 ("seq_file: Rename seq_overflow() to
     seq_has_overflowed() and make public")

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Lars Ellenberg <drbd-dev@lists.linbit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-15 16:35:25 -07:00
Rasmus Villemoes
41416f2330 lib/string_helpers.c: change semantics of string_escape_mem
The current semantics of string_escape_mem are inadequate for one of its
current users, vsnprintf().  If that is to honour its contract, it must
know how much space would be needed for the entire escaped buffer, and
string_escape_mem provides no way of obtaining that (short of allocating a
large enough buffer (~4 times input string) to let it play with, and
that's definitely a big no-no inside vsnprintf).

So change the semantics for string_escape_mem to be more snprintf-like:
Return the size of the output that would be generated if the destination
buffer was big enough, but of course still only write to the part of dst
it is allowed to, and (contrary to snprintf) don't do '\0'-termination.
It is then up to the caller to detect whether output was truncated and to
append a '\0' if desired.  Also, we must output partial escape sequences,
otherwise a call such as snprintf(buf, 3, "%1pE", "\123") would cause
printf to write a \0 to buf[2] but leaving buf[0] and buf[1] with whatever
they previously contained.

This also fixes a bug in the escaped_string() helper function, which used
to unconditionally pass a length of "end-buf" to string_escape_mem();
since the latter doesn't check osz for being insanely large, it would
happily write to dst.  For example, kasprintf(GFP_KERNEL, "something and
then %pE", ...); is an easy way to trigger an oops.

In test-string_helpers.c, the -ENOMEM test is replaced with testing for
getting the expected return value even if the buffer is too small.  We
also ensure that nothing is written (by relying on a NULL pointer deref)
if the output size is 0 by passing NULL - this has to work for
kasprintf("%pE") to work.

In net/sunrpc/cache.c, I think qword_add still has the same semantics.
Someone should definitely double-check this.

In fs/proc/array.c, I made the minimum possible change, but longer-term it
should stop poking around in seq_file internals.

[andriy.shevchenko@linux.intel.com: simplify qword_add]
[andriy.shevchenko@linux.intel.com: add missed curly braces]
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-15 16:35:24 -07:00