Use ARRAY_SIZE macro already defined in kernel.h
Signed-off-by: NAhmed S. Darwish <darwish.07@gmail.com>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Align the per cpu runqueue to the cacheline boundary.  This will minimize
the number of cachelines touched during remote wakeup.
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Acked-by: NIngo Molnar <mingo@elte.hu>
Cc: Ravikiran G Thirumalai <kiran@scalex86.org>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

- Make TASK_PREEMPTS_CURR(task, rq) return "true" only if the task's prio
  is higher than the current's one and the task is in the "active" array.
  This ensures we don't make redundant resched_task() calls when the task
  is in the "expired" array (as may happen now in set_user_prio(),
  rt_mutex_setprio() and pull_task() ) ;

- generalise conditions for a call to resched_task() in set_user_nice(),
  rt_mutex_setprio() and sched_setscheduler()
Signed-off-by: NDmitry Adamushko <dmitry.adamushko@gmail.com>
Cc: Con Kolivas <kernel@kolivas.org>
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>

When a logical cpu 'x' already has more than one process running, then most
likely the siblings of that cpu 'x' must be busy.  Otherwise the idle
siblings would have likely(in most of the scenarios) picked up the extra
load making the load on 'x' atmost one.

Use this logic to eliminate the siblings status check and minimize the cache
misses encountered on a heavily loaded system.
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
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>

I noticed expensive divides done in try_to_wakeup() and
find_busiest_group() on a bi dual core Opteron machine (total of 4 cores),
moderatly loaded (15.000 context switch per second)

oprofile numbers :

CPU: AMD64 processors, speed 2600.05 MHz (estimated)
Counted CPU_CLK_UNHALTED events (Cycles outside of halt state) with a unit
mask of 0x00 (No unit mask) count 50000
samples  %        symbol name
...
613914    1.0498  try_to_wake_up
    834  0.0013 :ffffffff80227ae1:   div    %rcx
77513  0.1191 :ffffffff80227ae4:   mov    %rax,%r11

608893    1.0413  find_busiest_group
   1841  0.0031 :ffffffff802260bf:       div    %rdi
140109  0.2394 :ffffffff802260c2:       test   %sil,%sil

Some of these divides can use the reciprocal divides we introduced some
time ago (currently used in slab AFAIK)

We can assume a load will fit in a 32bits number, because with a
SCHED_LOAD_SCALE=128 value, its still a theorical limit of 33554432

When/if we reach this limit one day, probably cpus will have a fast
hardware divide and we can zap the reciprocal divide trick.

Ingo suggested to rename cpu_power to __cpu_power to make clear it should
not be modified without changing its reciprocal value too.

I did not convert the divide in cpu_avg_load_per_task(), because tracking
nr_running changes may be not worth it ?  We could use a static table of 32
reciprocal values but it would add a conditional branch and table lookup.

[akpm@linux-foundation.org: !SMP build fix]
Signed-off-by: NEric Dumazet <dada1@cosmosbay.com>
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>

Fix the process idle load balancing in the presence of dynticks.  cpus for
which ticks are stopped will sleep till the next event wakes it up.
Potentially these sleeps can be for large durations and during which today,
there is no periodic idle load balancing being done.

This patch nominates an owner among the idle cpus, which does the idle load
balancing on behalf of the other idle cpus.  And once all the cpus are
completely idle, then we can stop this idle load balancing too.  Checks added
in fast path are minimized.  Whenever there are busy cpus in the system, there
will be an owner(idle cpu) doing the system wide idle load balancing.

Open items:
1. Intelligent owner selection (like an idle core in a busy package).
2. Merge with rcu's nohz_cpu_mask?
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Acked-by: NIngo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Periodic load balancing in recent kernels happen in the softirq.  In
certain -rt configurations, these softirqs are handled in softirqd context.
 And hence the check for idle processor was always returning busy (as
nr_running > 1).

This patch captures the idle information at the tick and passes this info
to softirq context through an element 'idle_at_tick' in rq.

[kernel@kolivas.org: Fix reverse idle at tick logic]
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Acked-by: NIngo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Karsten Keil <kkeil@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The CAPI 2.0 interface uses a semaphore as mutex.  Use the mutex API instead
of the (binary) semaphore.
Signed-off-by: NMatthias Kaehlcke <matthias.kaehlcke@gmail.com>
Cc: Karsten Keil <kkeil@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

the isdn_divertif contains kernel-only references so I've wrapped them in
__KERNEL__ and add proper #include statements.
Signed-off-by: NMike Frysinger <vapier@gentoo.org>
Cc: Karsten Keil <kkeil@suse.de>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix incorrect spinlock use in hysdn_log_close().  The function declared a
spinlock on the stack and used it to 'protect' a shared driver structure.

The patch simply removes the useless code.
Signed-off-by: NMatthias Kaehlcke <matthias.kaehlcke@gmail.com>
Cc: Karsten Keil <kkeil@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

As pointed out by Robert P.  J.  Day, here is a patch to remove unused
header files from Eicon/Dialogic ISDN driver.
Signed-off-by: NArmin Schindler <armin@melware.de>
Acked-by: NKarsten Keil <kkeil@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Acked-by: NKarsten Keil <kkeil@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch makes it so that simple_fill_super and get_sb_pseudo assign their
root inodes to be number 1.  It also fixes up a couple of callers of
simple_fill_super that were passing in files arrays that had an index at
number 1, and adds a warning for any caller that sends in such an array.

It would have been nice to have made it so that it wasn't possible to make
such a collision, but some callers need to be able to control what inode
number their entries get, so I think this is the best that can be done.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
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>

The problems are:

- on filesystems w/o permanent inode numbers, i_ino values can be larger
  than 32 bits, which can cause problems for some 32 bit userspace programs on
  a 64 bit kernel.  We can't do anything for filesystems that have actual
  >32-bit inode numbers, but on filesystems that generate i_ino values on the
  fly, we should try to have them fit in 32 bits.  We could trivially fix this
  by making the static counters in new_inode and iunique 32 bits, but...

- many filesystems call new_inode and assume that the i_ino values they are
  given are unique.  They are not guaranteed to be so, since the static
  counter can wrap.  This problem is exacerbated by the fix for #1.

- after allocating a new inode, some filesystems call iunique to try to get
  a unique i_ino value, but they don't actually add their inodes to the
  hashtable, and so they're still not guaranteed to be unique if that counter
  wraps.

This patch set takes the simpler approach of simply using iunique and hashing
the inodes afterward.  Christoph H.  previously mentioned that he thought that
this approach may slow down lookups for filesystems that currently hash their
inodes.

The questions are:

1) how much would this slow down lookups for these filesystems?
2) is it enough to justify adding more infrastructure to avoid it?

What might be best is to start with this approach and then only move to using
IDR or some other scheme if these extra inodes in the hashtable prove to be
problematic.

I've done some cursory testing with this patch and the overhead of hashing and
unhashing the inodes with pipefs is pretty low -- just a few seconds of system
time added on to the creation and destruction of 10 million pipes (very
similar to the overhead that the IDR approach would add).

The hard thing to measure is what effect this has on other filesystems. I'm
open to ways to try and gauge this.

Again, I've only converted pipefs as an example. If this approach is
acceptable then I'll start work on patches to convert other filesystems.

With a pretty-much-worst-case microbenchmark provided by Eric Dumazet
<dada1@cosmosbay.com>:

hashing patch (pipebench):
sys     1m15.329s
sys     1m16.249s
sys     1m17.169s

unpatched (pipebench):
sys     1m9.836s
sys     1m12.541s
sys     1m14.153s

Which works out to 1.05642174294555027017.  So ~5-6% slowdown.

This patch:

When a 32-bit program that was not compiled with large file offsets does a
stat and gets a st_ino value back that won't fit in the 32 bit field, glibc
(correctly) generates an EOVERFLOW error.  We can't do anything about fs's
with larger permanent inode numbers, but when we generate them on the fly, we
ought to try and have them fit within a 32 bit field.

This patch takes the first step toward this by making the static counters in
these two functions be 32 bits.

[jlayton@redhat.com: mention that it's only the case for 32bit, non-LFS stat]
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
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>

Here is a driver for the Alchemy au1550 PSC (Programmable Serial
Controller) in SPI master mode.

It supports dma transfers using the Alchemy descriptor based dma controller
for 4-8 bits per word SPI transfers.  For 9-24 bits per word transfers, pio
irq based mode is used to avoid setup of dma channels from scratch on each
number of bits per word change.

Tested with au1550; this may also work on other MIPS Alchemy cpus, like
au1200/au1210/au1250.  Used extensively with SD card connected via SPI;
this handles 8.1MHz SPI clock transfers using dma without any problem (the
highest SPI clock freq possible with au1550 running on 324MHz).

The driver supports sharing of SPI bus by multiple devices.  All features
of Alchemy SPI mode are supported (all SPI modes, msb/lsb first, bits per
word in 4-24 range).

As the SPI clock of the controller depends on main input clock that shall
be configured externally, platform data structure for au1550 SPI controller
driver contains mainclk_hz attribute to define the input clock rate.  From
this value, dividers of the controller for SPI clock are set up for
required frequency.
Signed-off-by: NJan Nikitenko <jan.nikitenko@gmail.com>

Whitespace and section fixups.  Remove partial workaround for platform
setup bug in dma_mask setup; it couldn't work with multiple controllers.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Various documentation updates for the SPI infrastructure, to clarify things
that may not have been clear, to cope with lack of editing, and fix
omissions.

Also, plug SPI into the kernel-api DocBook template, and fix all the
resulting glitches in document generation.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add a filesystem API for <linux/spi/spi.h> stack.  The initial version of
this interface is purely synchronous.

dbrownell@users.sourceforge.net:

 Cleaned up, bugfixed; much simplified; added preliminary documentation.

 Works with mdev given CONFIG_SYSFS_DEPRECATED; and presumably udev.

 Updated SPI_IOC_MESSAGE ioctl to full spi_message semantics, supporting
 groups of one or more transfers (each of which may be full duplex if
 desired).

 This is marked as EXPERIMENTAL with an explicit disclaimer that the API
 (notably the ioctls) is subject to change.
Signed-off-by: NAndrea Paterniani <a.paterniani@swapp-eng.it>
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Simplify the spi_butterfly driver by removing incomplete/unused support for
the second SPI bus, implemented by the USI controller.  This should make
this a clearer example of how to write a parport bitbang driver.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Remove some obviously old interrupt disable/enable code that has been
commented out.
Signed-off-by: NJosh Boyer <jwboyer@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The misc character device driver uses a semaphore as mutex.  Use the mutex API
instead of the (binary) semaphore.
Signed-off-by: NMatthias Kaehlcke <matthias.kaehlcke@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The hdaps driver uses a semaphore as mutex.  Use the mutex API instead of the
(binary) semaphore.
Signed-off-by: NMatthias Kaehlcke <matthias.kaehlcke@gmail.com>
Cc: Robert Love <rlove@rlove.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The TPM driver uses two semaphores as mutexes.  Use the mutex API instead of
the (binary) semaphores.
Signed-off-by: NMatthias Kaehlcke <matthias.kaehlcke@gmail.com>
Cc: Kylene Hall <kjhall@us.ibm.com>
Cc: Marcel Selhorst <tpm@selhorst.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The RocketPort driver uses a semaphore as mutex.  Use the mutex API instead of
the (binary) semaphore.
Signed-off-by: NMatthias Kaehlcke <matthias.kaehlcke@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Other symbols of the hrtimers API are already exported.
Signed-off-by: NStas Sergeev <stsp@aknet.ru>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When elf loader fails to map executable (due to memory shortage or because
binary is malformed), it can return 0.  Normally, this is invisible because
process is killed with SIGKILL and it never returns to user space.

But if exec() is called from kernel thread (hotplug, whatever)
consequences are more interesting and vary depending on architecture.

i386.   Nothing especially interesting, execve() just returns
        with "success"  :-)

x86_64. Fake zero frame is used on way to caller, RSP/RIP are loaded
        with zeros, ergo... double fault.

ia64.   Similar to i386, but r32...r95 are corrupted. Sometimes it
        oopses due to return to zero PC, sometimes it sees NaT in
        rXX and oopses due to NaT consumption.
Signed-off-by: NAlexey Kuznetsov <alexey@openvz.org>
Signed-off-by: NKirill Korotaev <dev@openvz.org>
Signed-off-by: NPavel Emelianov <xemul@openvz.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix misnamed fields of 'struct clock_event_device' in the kernel-doc
comment.  Convert the acronyms to uppercase, while at it...
Signed-off-by: NSergei Shtylyov <sshtylyov@ru.mvista.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

librs docbook typo fixes.
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NMike Frysinger <vapier@gentoo.org>
Acked-by: NJan Kara <jack@ucw.cz>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add taskstats.h to include/linux/Kbuild, make headers_install would then
pickup taskstats.h.  This needs to be done as taskstats.h is a user
interface header.
Signed-off-by: NBalbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>
Cc: Don Zickus <dzickus@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Change synclink_gt driver to use dynamic tty device registration.
Signed-off-by: NPaul Fulghum <paulkf@microgate.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add sensable phantom driver
Signed-off-by: NJiri Slaby <jirislaby@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

You currently cannot remove all cpus or mems from cpus_allowed or
mems_allowed of a cpuset.  We now allow both if there are no attached
tasks.
Acked-by: NPaul Jackson <pj@sgi.com>
Cc: Christoph Lameter <clameter@engr.sgi.com>
Signed-off-by: NPaul Menage <menage@google.com>
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Cleanup using simple_read_from_buffer() in procfs.
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>

There is a new list for kexec/kdump discussion.
Signed-off-by: NSimon Horman <horms@verge.net.au>
Acked-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

I noticed that the moxa input checking security bug described by
CVE-2005-0504 appears to remain unfixed upstream.

The issue is described here:
  http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2005-0504

Debian has been shipping the following patch from Andres Salomon.

(akpm: it's a privileged operation)
Signed-off-by: Ndann frazier <dannf@hp.com>
Signed-off-by: NAndres Salomon <dilinger@debian.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Don't clobber error from sys_ioctl in HDIO_GETGEO compat wrapper.
Signed-off-by: NAndreas Schwab <schwab@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NZach Carter <linux@zachcarter.com>
Cc: Bart Samwel <bart@samwel.tk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Remove duplicate 'U' entry -- fix mis-merge.
Signed-off-by: NMichal Piotrowski <michal.k.k.piotrowski@gmail.com>
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

It appears that a minor thinko occurred in udf_rmdir and the
(already-cleared) link count on the directory that is being removed was
being decremented instead of the link count on its parent directory.  This
gives rise to lots of kernel messages similar to:

UDF-fs warning (device loop1): udf_rmdir: empty directory has nlink != 2 (8)

when removing directory trees.  No other ill effects have been observed but
I guess it could theoretically result in the link count overflowing on a
very long-lived, much modified directory.
Signed-off-by: NStephen Mollett <molletts@yahoo.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Jan Kara <jack@ucw.cz>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>