Commit Graph

2079 Commits

Author SHA1 Message Date
Linus Torvalds
d14b7a419a Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull trivial tree from Jiri Kosina:
 "Trivial updates all over the place as usual."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (29 commits)
  Fix typo in include/linux/clk.h .
  pci: hotplug: Fix typo in pci
  iommu: Fix typo in iommu
  video: Fix typo in drivers/video
  Documentation: Add newline at end-of-file to files lacking one
  arm,unicore32: Remove obsolete "select MISC_DEVICES"
  module.c: spelling s/postition/position/g
  cpufreq: Fix typo in cpufreq driver
  trivial: typo in comment in mksysmap
  mach-omap2: Fix typo in debug message and comment
  scsi: aha152x: Fix sparse warning and make printing pointer address more portable.
  Change email address for Steve Glendinning
  Btrfs: fix typo in convert_extent_bit
  via: Remove bogus if check
  netprio_cgroup.c: fix comment typo
  backlight: fix memory leak on obscure error path
  Documentation: asus-laptop.txt references an obsolete Kconfig item
  Documentation: ManagementStyle: fixed typo
  mm/vmscan: cleanup comment error in balance_pgdat
  mm: cleanup on the comments of zone_reclaim_stat
  ...
2012-07-24 13:34:56 -07:00
Linus Torvalds
3c4cfadef6 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking changes from David S Miller:

 1) Remove the ipv4 routing cache.  Now lookups go directly into the FIB
    trie and use prebuilt routes cached there.

    No more garbage collection, no more rDOS attacks on the routing
    cache.  Instead we now get predictable and consistent performance,
    no matter what the pattern of traffic we service.

    This has been almost 2 years in the making.  Special thanks to
    Julian Anastasov, Eric Dumazet, Steffen Klassert, and others who
    have helped along the way.

    I'm sure that with a change of this magnitude there will be some
    kind of fallout, but such things ought the be simple to fix at this
    point.  Luckily I'm not European so I'll be around all of August to
    fix things :-)

    The major stages of this work here are each fronted by a forced
    merge commit whose commit message contains a top-level description
    of the motivations and implementation issues.

 2) Pre-demux of established ipv4 TCP sockets, saves a route demux on
    input.

 3) TCP SYN/ACK performance tweaks from Eric Dumazet.

 4) Add namespace support for netfilter L4 conntrack helpers, from Gao
    Feng.

 5) Add config mechanism for Energy Efficient Ethernet to ethtool, from
    Yuval Mintz.

 6) Remove quadratic behavior from /proc/net/unix, from Eric Dumazet.

 7) Support for connection tracker helpers in userspace, from Pablo
    Neira Ayuso.

 8) Allow userspace driven TX load balancing functions in TEAM driver,
    from Jiri Pirko.

 9) Kill off NLMSG_PUT and RTA_PUT macros, more gross stuff with
    embedded gotos.

10) TCP Small Queues, essentially minimize the amount of TCP data queued
    up in the packet scheduler layer.  Whereas the existing BQL (Byte
    Queue Limits) limits the pkt_sched --> netdevice queuing levels,
    this controls the TCP --> pkt_sched queueing levels.

    From Eric Dumazet.

11) Reduce the number of get_page/put_page ops done on SKB fragments,
    from Alexander Duyck.

12) Implement protection against blind resets in TCP (RFC 5961), from
    Eric Dumazet.

13) Support the client side of TCP Fast Open, basically the ability to
    send data in the SYN exchange, from Yuchung Cheng.

    Basically, the sender queues up data with a sendmsg() call using
    MSG_FASTOPEN, then they do the connect() which emits the queued up
    fastopen data.

14) Avoid all the problems we get into in TCP when timers or PMTU events
    hit a locked socket.  The TCP Small Queues changes added a
    tcp_release_cb() that allows us to queue work up to the
    release_sock() caller, and that's what we use here too.  From Eric
    Dumazet.

15) Zero copy on TX support for TUN driver, from Michael S. Tsirkin.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1870 commits)
  genetlink: define lockdep_genl_is_held() when CONFIG_LOCKDEP
  r8169: revert "add byte queue limit support".
  ipv4: Change rt->rt_iif encoding.
  net: Make skb->skb_iif always track skb->dev
  ipv4: Prepare for change of rt->rt_iif encoding.
  ipv4: Remove all RTCF_DIRECTSRC handliing.
  ipv4: Really ignore ICMP address requests/replies.
  decnet: Don't set RTCF_DIRECTSRC.
  net/ipv4/ip_vti.c: Fix __rcu warnings detected by sparse.
  ipv4: Remove redundant assignment
  rds: set correct msg_namelen
  openvswitch: potential NULL deref in sample()
  tcp: dont drop MTU reduction indications
  bnx2x: Add new 57840 device IDs
  tcp: avoid oops in tcp_metrics and reset tcpm_stamp
  niu: Change niu_rbr_fill() to use unlikely() to check niu_rbr_add_page() return value
  niu: Fix to check for dma mapping errors.
  net: Fix references to out-of-scope variables in put_cmsg_compat()
  net: ethernet: davinci_emac: add pm_runtime support
  net: ethernet: davinci_emac: Remove unnecessary #include
  ...
2012-07-24 10:01:50 -07:00
Linus Torvalds
474183b188 Merge tag 'please-pull-misc-3.6' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux
Pull misc Itanium fixes from Tony Luck.

* tag 'please-pull-misc-3.6' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux:
  debug: Do not permit CONFIG_DEBUG_STACK_USAGE=y on IA64 or PARISC
  [IA64] Port OOM changes to ia64_do_page_fault
2012-07-23 19:10:12 -07:00
Linus Torvalds
e05644e17e Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security subsystem updates from James Morris:
 "Nothing groundbreaking for this kernel, just cleanups and fixes, and a
  couple of Smack enhancements."

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (21 commits)
  Smack: Maintainer Record
  Smack: don't show empty rules when /smack/load or /smack/load2 is read
  Smack: user access check bounds
  Smack: onlycap limits on CAP_MAC_ADMIN
  Smack: fix smack_new_inode bogosities
  ima: audit is compiled only when enabled
  ima: ima_initialized is set only if successful
  ima: add policy for pseudo fs
  ima: remove unused cleanup functions
  ima: free securityfs violations file
  ima: use full pathnames in measurement list
  security: Fix nommu build.
  samples: seccomp: add .gitignore for untracked executables
  tpm: check the chip reference before using it
  TPM: fix memleak when register hardware fails
  TPM: chip disabled state erronously being reported as error
  MAINTAINERS: TPM maintainers' contacts update
  Merge branches 'next-queue' and 'next' into next
  Remove unused code from MPI library
  Revert "crypto: GnuPG based MPI lib - additional sources (part 4)"
  ...
2012-07-23 18:49:06 -07:00
Linus Torvalds
16d286e656 Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RCU changes from Ingo Molnar:
 "Quoting from Paul, the major features of this series are:

  1. Preventing latency spikes of more than 200 microseconds for
     kernels built with NR_CPUS=4096, which is reportedly becoming the
     default for some distros.  This is a first step, as it does not
     help with systems that actually -have- 4096 CPUs (work on this case
     is in progress, but is not yet ready for mainline).

     This category also includes improving concurrency of rcu_barrier(),
     placed here due to conflicts.  Posted to LKML at:

      https://lkml.org/lkml/2012/6/22/381

     Note that patches 18-22 of that series have been defered to 3.7, as
     they have not yet proven themselves to be mainline-ready (and yes,
     these are the ones intended to get rid of RCU's latency spikes for
     systems that actually have 4096 CPUs).

  2. Updates to documentation and rcutorture fixes, the latter category
     including improvements to rcu_barrier() testing.  Posted to LKML at

      http://lkml.indiana.edu/hypermail/linux/kernel/1206.1/04094.html.

  3. Miscellaneous fixes posted to LKML at:

      https://lkml.org/lkml/2012/6/22/500

     with the exception of the last commit, which was posted here:

      http://www.gossamer-threads.com/lists/linux/kernel/1561830

  4. RCU_FAST_NO_HZ fixes and improvements.  Posted to LKML at:

      http://lkml.indiana.edu/hypermail/linux/kernel/1206.1/00006.html
      http://www.gossamer-threads.com/lists/linux/kernel/1561833

     The first four patches of the first series went into 3.5 to fix a
     regression.

  5. Code-style fixes.  These were posted to LKML at

      http://lkml.indiana.edu/hypermail/linux/kernel/1205.2/01180.html
      http://lkml.indiana.edu/hypermail/linux/kernel/1205.2/01181.html"

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (48 commits)
  rcu: Fix broken strings in RCU's source code.
  rcu: Fix code-style issues involving "else"
  rcu: Introduce check for callback list/count mismatch
  rcu: Make RCU_FAST_NO_HZ respect nohz= boot parameter
  rcu: Fix qlen_lazy breakage
  rcu: Round FAST_NO_HZ lazy timeout to nearest second
  rcu: The rcu_needs_cpu() function is not a quiescent state
  rcu: Dump only the current CPU's buffers for idle-entry/exit warnings
  rcu: Add check for CPUs going offline with callbacks queued
  rcu: Disable preemption in rcu_blocking_is_gp()
  rcu: Prevent uninitialized string in RCU CPU stall info
  rcu: Fix rcu_is_cpu_idle() #ifdef in TINY_RCU
  rcu: Split RCU core processing out of __call_rcu()
  rcu: Prevent __call_rcu() from invoking RCU core on offline CPUs
  rcu: Make __call_rcu() handle invocation from idle
  rcu: Remove function versions of __kfree_rcu and __is_kfree_rcu_offset
  rcu: Consolidate tree/tiny __rcu_read_{,un}lock() implementations
  rcu: Remove return value from rcu_assign_pointer()
  key: Remove extraneous parentheses from rcu_assign_keypointer()
  rcu: Remove return value from RCU_INIT_POINTER()
  ...
2012-07-22 10:45:05 -07:00
David S. Miller
abaa72d7fd Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
2012-07-19 11:17:30 -07:00
Tony Luck
e9c31b32f1 debug: Do not permit CONFIG_DEBUG_STACK_USAGE=y on IA64 or PARISC
The stack_not_used() function in <linux/sched.h> assumes that stacks
grow downwards. This is not true on IA64 or PARISC, so this function
would walk off in the wrong direction and into the weeds.

Found on IA64 because of a compilation failure with recursive dependencies
on IA64_TASKSIZE and IA64_THREAD_INFO_SIZE.

Fixing the code is possible, but should be combined with other
infrastructure additions to set up the "canary" at the end of the stack.

Reported-by: Fengguang Wu <fengguang.wu@intel.com> (failed allmodconfig build)
Signed-off-by: Tony Luck <tony.luck@intel.com>
2012-07-19 10:36:45 -07:00
Linus Torvalds
17fae1cdea Merge tag 'iommu-fixes-v3.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu
Pull IOMMU fixes from Joerg Roedel:
 "The patches fix several issues in the AMD IOMMU driver, the NVidia
  SMMU driver, and the DMA debug code.

  The most important fix for the AMD IOMMU solves a problem with SR-IOV
  devices where virtual functions did not work with IOMMU enabled.  The
  NVidia SMMU patch fixes a possible sleep while spin-lock situation
  (queued the small fix for v3.5, a better but more intrusive fix is
  coming for v3.6).  The DMA debug patches fix a possible data
  corruption issue due to bool vs u32 usage."

* tag 'iommu-fixes-v3.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  iommu/amd: fix type bug in flush code
  dma-debug: debugfs_create_bool() takes a u32 pointer
  iommu/tegra: smmu: Fix unsleepable memory allocation
  iommu/amd: Initialize dma_ops for hotplug and sriov devices
  iommu/amd: Fix missing iommu_shutdown initialization in passthrough mode
2012-07-09 10:57:21 -07:00
Paul E. McKenney
5cf05ad758 rcu: Fix broken strings in RCU's source code.
Although the C language allows you to break strings across lines, doing
this makes it hard for people to find the Linux kernel code corresponding
to a given console message.  This commit therefore fixes broken strings
throughout RCU's source code.

Suggested-by: Josh Triplett <josh@joshtriplett.org>
Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2012-07-06 06:01:49 -07:00
Dan Carpenter
68ee6d2237 dma-debug: debugfs_create_bool() takes a u32 pointer
Even though it has "bool" in the name, you have pass a u32 pointer to
debugfs_create_bool().  Otherwise you get memory corruption in
write_file_bool().  Fortunately in this case the corruption happens in
an alignment hole between variables so it doesn't cause any problems.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2012-07-02 12:11:40 +02:00
Pablo Neira Ayuso
a31f2d17b3 netlink: add netlink_kernel_cfg parameter to netlink_kernel_create
This patch adds the following structure:

struct netlink_kernel_cfg {
        unsigned int    groups;
        void            (*input)(struct sk_buff *skb);
        struct mutex    *cb_mutex;
};

That can be passed to netlink_kernel_create to set optional configurations
for netlink kernel sockets.

I've populated this structure by looking for NULL and zero parameters at the
existing code. The remaining parameters that always need to be set are still
left in the original interface.

That includes optional parameters for the netlink socket creation. This allows
easy extensibility of this interface in the future.

This patch also adapts all callers to use this new interface.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-29 16:46:02 -07:00
Jiri Kosina
59f91e5dd0 Merge branch 'master' into for-next
Conflicts:
	include/linux/mmzone.h

Synced with Linus' tree so that trivial patch can be applied
on top of up-to-date code properly.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
2012-06-29 14:45:58 +02:00
Akinobu Mita
422aa27420 lib: correct link to the original source for div64_u64
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Jiri Kosina <trivial@kernel.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-06-28 11:51:39 +02:00
Anton Blanchard
f39cdaebb8 fault-inject: avoid call to random32() if fault injection is disabled
After enabling CONFIG_FAILSLAB I noticed random32 in profiles even if slub
fault injection wasn't enabled at runtime.

should_fail forces a comparison against random32() even if probability is
0:

        if (attr->probability <= random32() % 100)
                return false;

Add a check up front for probability == 0 and avoid all of the more
complicated checks.

Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-20 14:39:36 -07:00
Linus Torvalds
a95f9b6e09 Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull core updates (RCU and locking) from Ingo Molnar:
 "Most of the diffstat comes from the RCU slow boot regression fixes,
  but there's also a debuggability improvements/fixes."

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  memblock: Document memblock_is_region_{memory,reserved}()
  rcu: Precompute RCU_FAST_NO_HZ timer offsets
  rcu: Move RCU_FAST_NO_HZ per-CPU variables to rcu_dynticks structure
  rcu: Update RCU_FAST_NO_HZ tracing for lazy callbacks
  rcu: RCU_FAST_NO_HZ detection of callback adoption
  spinlock: Indicate that a lockup is only suspected
  kdump: Execute kmsg_dump(KMSG_DUMP_PANIC) after smp_send_stop()
  panic: Make panic_on_oops configurable
2012-06-15 16:52:35 -07:00
James Morris
66dd07b88a Merge commit 'v3.5-rc2' into next 2012-06-10 22:52:10 +10:00
Joern Engel
39caa0916e btree: catch NULL value before it does harm
Storing NULL values in the btree is illegal and can lead to memory
corruption and possible other fun as well.  Catch it on insert, instead
of waiting for the inevitable.

Signed-off-by: Joern Engel <joern@logfs.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-07 14:43:55 -07:00
Roland Dreier
cbf8ae32f6 btree: fix tree corruption in btree_get_prev()
The memory the parameter __key points to is used as an iterator in
btree_get_prev(), so if we save off a bkey() pointer in retry_key and
then assign that to __key, we'll end up corrupting the btree internals
when we do eg

	longcpy(__key, bkey(geo, node, i), geo->keylen);

to return the key value.  What we should do instead is use longcpy() to
copy the key value that retry_key points to __key.

This can cause a btree to get corrupted by seemingly read-only
operations such as btree_for_each_safe.

[akpm@linux-foundation.org: avoid the double longcpy()]
Signed-off-by: Roland Dreier <roland@purestorage.com>
Acked-by: Joern Engel <joern@logfs.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-07 14:43:55 -07:00
Linus Torvalds
374916ed16 Merge tag 'md-3.5-fixes' of git://neil.brown.name/md
Pull two md fixes from NeilBrown:
 "One sparse-warning fix, one bugfix for 3.4-stable"

* tag 'md-3.5-fixes' of git://neil.brown.name/md:
  md: raid1/raid10: fix problem with merge_bvec_fn
  lib/raid6: fix sparse warnings in recovery functions
2012-06-06 09:49:28 -07:00
Christian Borntraeger
8a173b1476 spinlock: Indicate that a lockup is only suspected
On an over-committed KVM system we got a:

  "BUG: spinlock lockup on CPU#2, swapper/2/0"

message on the heavily contended virtio blk spinlock.

While we might want to reconsider the locking of virtio-blk
(lock is held while switching to the host) this patch tries to
make the message clearer: the lockup is only suspected.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1338283124-7063-1-git-send-email-borntraeger@de.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-06 11:34:20 +02:00
Ingo Molnar
c7f5f4ab10 Merge branch 'core/debug' into core/urgent
Merge two debugging patchlets that were waiting for
preparatory commits to hit upstream.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-06-06 11:12:55 +02:00
Konstantin Khlebnikov
fffaee365f radix-tree: fix contiguous iterator
This patch fixes bug in macro radix_tree_for_each_contig().

If radix_tree_next_slot() sees NULL in next slot it returns NULL, but following
radix_tree_next_chunk() switches iterating into next chunk. As result iterating
becomes non-contiguous and breaks vfs "splice" and all its users.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Reported-and-bisected-by: Hans de Bruin <jmdebruin@xmsnet.nl>
Reported-and-bisected-by: Ondrej Zary <linux@rainbow-software.org>
Reported-bisected-and-tested-by: Toralf Förster <toralf.foerster@gmx.de>
Link: https://lkml.org/lkml/2012/6/5/64
Cc: stable <stable@vger.kernel.org> # 3.4.x
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-05 10:46:40 -07:00
Linus Torvalds
4fc3acf291 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking updates from David Miller:

 1) Make syn floods consume significantly less resources by

    a) Not pre-COW'ing routing metrics for SYN/ACKs
    b) Mirroring the device queue mapping of the SYN for the SYN/ACK
       reply.

    Both from Eric Dumazet.

 2) Fix calculation errors in Byte Queue Limiting, from Hiroaki SHIMODA.

 3) Validate the length requested when building a paged SKB for a
    socket, so we don't overrun the page vector accidently.  From Jason
    Wang.

 4) When netlabel is disabled, we abort all IP option processing when we
    see a CIPSO option.  This isn't the right thing to do, we should
    simply skip over it and continue processing the remaining options
    (if any).  Fix from Paul Moore.

 5) SRIOV fixes for the mellanox driver from Jack orgenstein and Marcel
    Apfelbaum.

 6) 8139cp enables the receiver before the ring address is properly
    programmed, which potentially lets the device crap over random
    memory.  Fix from Jason Wang.

 7) e1000/e1000e fixes for i217 RST handling, and an improper buffer
    address reference in jumbo RX frame processing from Bruce Allan and
    Sebastian Andrzej Siewior, respectively.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  fec_mpc52xx: fix timestamp filtering
  mcs7830: Implement link state detection
  e1000e: fix Rapid Start Technology support for i217
  e1000: look into the page instead of skb->data for e1000_tbi_adjust_stats()
  r8169: call netif_napi_del at errpaths and at driver unload
  tcp: reflect SYN queue_mapping into SYNACK packets
  tcp: do not create inetpeer on SYNACK message
  8139cp/8139too: terminate the eeprom access with the right opmode
  8139cp: set ring address before enabling receiver
  cipso: handle CIPSO options correctly when NetLabel is disabled
  net: sock: validate data_len before allocating skb in sock_alloc_send_pskb()
  bql: Avoid possible inconsistent calculation.
  bql: Avoid unneeded limit decrement.
  bql: Fix POSDIFF() to integer overflow aware.
  net/mlx4_core: Fix obscure mlx4_cmd_box parameter in QUERY_DEV_CAP
  net/mlx4_core: Check port out-of-range before using in mlx4_slave_cap
  net/mlx4_core: Fixes for VF / Guest startup flow
  net/mlx4_en: Fix improper use of "port" parameter in mlx4_en_event
  net/mlx4_core: Fix number of EQs used in ICM initialisation
  net/mlx4_core: Fix the slave_id out-of-range test in mlx4_eq_int
2012-06-02 16:22:51 -07:00
Linus Torvalds
08615d7d85 Merge branch 'akpm' (Andrew's patch-bomb)
Merge misc patches from Andrew Morton:

 - the "misc" tree - stuff from all over the map

 - checkpatch updates

 - fatfs

 - kmod changes

 - procfs

 - cpumask

 - UML

 - kexec

 - mqueue

 - rapidio

 - pidns

 - some checkpoint-restore feature work.  Reluctantly.  Most of it
   delayed a release.  I'm still rather worried that we don't have a
   clear roadmap to completion for this work.

* emailed from Andrew Morton <akpm@linux-foundation.org>: (78 patches)
  kconfig: update compression algorithm info
  c/r: prctl: add ability to set new mm_struct::exe_file
  c/r: prctl: extend PR_SET_MM to set up more mm_struct entries
  c/r: procfs: add arg_start/end, env_start/end and exit_code members to /proc/$pid/stat
  syscalls, x86: add __NR_kcmp syscall
  fs, proc: introduce /proc/<pid>/task/<tid>/children entry
  sysctl: make kernel.ns_last_pid control dependent on CHECKPOINT_RESTORE
  aio/vfs: cleanup of rw_copy_check_uvector() and compat_rw_copy_check_uvector()
  eventfd: change int to __u64 in eventfd_signal()
  fs/nls: add Apple NLS
  pidns: make killed children autoreap
  pidns: use task_active_pid_ns in do_notify_parent
  rapidio/tsi721: add DMA engine support
  rapidio: add DMA engine support for RIO data transfers
  ipc/mqueue: add rbtree node caching support
  tools/selftests: add mq_perf_tests
  ipc/mqueue: strengthen checks on mqueue creation
  ipc/mqueue: correct mq_attr_ok test
  ipc/mqueue: improve performance of send/recv
  selftests: add mq_open_tests
  ...
2012-05-31 18:10:18 -07:00
Denys Vlasenko
133fd9f5cd vsprintf: further optimize decimal conversion
Previous code was using optimizations which were developed to work well
even on narrow-word CPUs (by today's standards).  But Linux runs only on
32-bit and wider CPUs.  We can use that.

First: using 32x32->64 multiply and trivial 32-bit shift, we can correctly
divide by 10 much larger numbers, and thus we can print groups of 9 digits
instead of groups of 5 digits.

Next: there are two algorithms to print larger numbers.  One is generic:
divide by 1000000000 and repeatedly print groups of (up to) 9 digits.
It's conceptually simple, but requires an (unsigned long long) /
1000000000 division.

Second algorithm splits 64-bit unsigned long long into 16-bit chunks,
manipulates them cleverly and generates groups of 4 decimal digits.  It so
happens that it does NOT require long long division.

If long is > 32 bits, division of 64-bit values is relatively easy, and we
will use the first algorithm.  If long long is > 64 bits (strange
architecture with VERY large long long), second algorithm can't be used,
and we again use the first one.

Else (if long is 32 bits and long long is 64 bits) we use second one.

And third: there is a simple optimization which takes fast path not only
for zero as was done before, but for all one-digit numbers.

In all tested cases new code is faster than old one, in many cases by 30%,
in few cases by more than 50% (for example, on x86-32, conversion of
12345678).  Code growth is ~0 in 32-bit case and ~130 bytes in 64-bit
case.

This patch is based upon an original from Michal Nazarewicz.

[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Cc: Douglas W Jones <jones@cs.uiowa.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-31 17:49:27 -07:00