Граф коммитов

1257 Коммитов

Автор SHA1 Сообщение Дата
Martin Schwidefsky d2013485a5 [PATCH] s390: ioprio & inotify system calls.
Add system calls for io priorities and inotify.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-08-01 21:37:59 -07:00
Eugene Surovegin 4374ae10e5 [PATCH] ppc32: add missing 4xx EMAC sysfs nodes
Add missing 4xx EMAC data sysfs nodes.

Signed-off-by: Eugene Surovegin <ebs@ebshome.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-08-01 19:14:02 -07:00
Matt Porter c9cf73aee1 [PATCH] ppc32: add 440ep support
Add PPC440EP core support.  PPC440EP is a PPC440-based SoC with a classic PPC
FPU and another set of peripherals.

Signed-off-by: Wade Farnsworth <wfarnsworth@mvista.com>
Signed-off-by: Matt Porter <mporter@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-08-01 19:14:01 -07:00
Mauro Carvalho Chehab fd3113e84e [PATCH] V4L: Miscellaneous fixes
- Fixed some bttv card numbers.

- BTTV and SAA7134 version numbers incremented to reflect changes.

- pci_dma_supported() is called after pci_set_dma_mask() which
  already did check that for us. This patch removes the unneeded call to
  pci_dma_supported() at bttv-driver.c

- Ensure a sufficient I2C bus idle time between 2 messages for
  saa7134-i2c.c

- It is important to write at first to MO_GP3_IO for cx88-tvaudio.c

- Use try_to_freeze() instead of refrigerator at msp3400.c

- Recognizing the MFPE05-2 Tuner at tveeprom.c

- Add new parameter to help identify radio chipsets at tuner module:
  show_i2c=1 will show 16 reading bytes from detected tuners.

- BTTV does generate some Unimplemented IOCTL log at tuner module:
  0x40046d11(dir=1,tp=0x6d,nr=17,sz=4) means that it is sending
  MSP3400 calls to non-msp3400 tuners. Warning eliminated.
  VIDIOSAUDIO is also called, so debug messages updated. It is still
  requiring IOCTL implementation.

- Added two more tuners.

- Add support for the SVideo input on the GDI Black Gold.

Signed-off-by: Peter Missel <peter.missel@onlinehome.de>
Signed-off-by: Graham Bevan <graham.bevan@ntlworld.com>
Signed-off-by: Torsten Seeboth <Torsten.Seeboth@t-online.de>
Signed-off-by: Hartmut Hackmann <hartmut.hackmann@t.online.de>
Signed-off-by: Tobias Klauser <tklauser@nuerscht.ch>
Signed-off-by: Michael Krufky <mkrufky@m1k.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@brturbo.com.br>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-08-01 19:13:59 -07:00
John McCutchan 7544953685 [PATCH] inotify: fix file deletion by rename detection
When a file is moved over an existing file that you are watching,
inotify won't send you a DELETE_SELF event and it won't unref the inode
until the inotify instance is closed by the application.

Signed-off-by: John McCutchan <ttb@tentacle.dhs.org>
Signed-off-by: Robert Love <rml@novell.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-08-01 09:16:53 -07:00
Baruch Even d1b04c081e [NET]: Spelling mistakes threshoulds -> thresholds
Just simple spelling mistake fixes.

Signed-Off-By: Baruch Even <baruch@ev-en.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-07-30 17:41:59 -07:00
Linus Torvalds 6d1d07e41a Merge master.kernel.org:/pub/scm/linux/kernel/git/lenb/to-linus 2005-07-30 10:15:57 -07:00
Robert Love 5fa918b451 [PATCH] ppc64: inotify syscalls
inotify system call support for PPC64

[ I don't think we need sys32 compatibility versions--and if we do, I
failed in life. ]

Signed-off-by: Robert Love <rml@novell.com>
Acked-by: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-30 10:14:46 -07:00
Robert Love 141d751e26 [PATCH] ppc32: inotify syscalls
Add inotify system call stubs to PPC32.

Signed-off-by: Robert Love <rml@novell.com>
Acked-by: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-30 10:14:46 -07:00
Len Brown adbedd3424 merge 2.6.13-rc4 with ACPI's to-linus tree 2005-07-30 01:55:32 -04:00
Len Brown d6ac1a7910 /home/lenb/src/to-linus branch 'acpi-2.6.12' 2005-07-29 23:31:17 -04:00
David Shaohua Li 87bec66b96 [ACPI] suspend/resume ACPI PCI Interrupt Links
Add reference count and disable ACPI PCI Interrupt Link
when no device still uses it.

Warn when drivers have not released Link at suspend time.

http://bugzilla.kernel.org/show_bug.cgi?id=3469

Signed-off-by: David Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
2005-07-29 22:49:38 -04:00
Eric W. Biederman 3d483f4757 [PATCH] Fix sync_tsc hang
sync_tsc was using smp_call_function to ask the boot processor to report
it's tsc value.  smp_call_function performs an IPI_send_allbutself which is
a broadcast ipi.  There is a window during processor startup during which
the target cpu has started and before it has initialized it's interrupt
vectors so it can properly process an interrupt.  Receveing an interrupt
during that window will triple fault the cpu and do other nasty things.

Why cli does not protect us from that is beyond me.

The simple fix is to match ia64 and provide a smp_call_function_single.
Which avoids the broadcast and is more efficient.

This certainly fixes the problem of getting stuck on boot which was
very easy to trigger on my SMP Hyperthreaded Xeon, and I think
it fixes it for the right reasons.

Minor changes by AK

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-29 15:01:13 -07:00
Kumar Gala a46e812620 [PATCH] PCI: fix up errors after dma bursting patch and CONFIG_PCI=n -- bug?
In the patch from:

http://www.uwsg.iu.edu/hypermail/linux/kernel/0506.3/0985.html

Is the the following line suppose inside the if CONFIG_PCI=n

  #define pci_dma_burst_advice(pdev, strat, strategy_parameter) do { } while (0)

Signed-off-by: Kumar Gala <kumar.gala@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-29 13:12:52 -07:00
Eric W. Biederman 8bf2755664 [PATCH] x86_64 machine_kexec: Use standard pagetable helpers
Use the standard hardware page table manipulation macros.
This is possible now that linux works with all 4 levels
of the page tables.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-29 13:12:49 -07:00
Linus Torvalds d6d2a2ab05 x86: fix new find_first_bit()
Some edge problems with the original C rewrite.

Thanks go to Cal Peake, who pinpointed the breakage to the rewrite, and
tested this fixed version.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-29 11:01:22 -04:00
Linus Torvalds e0d7ff168a Merge master.kernel.org:/pub/scm/linux/kernel/git/dtor/input 2005-07-29 09:48:34 -07:00
Linus Torvalds ca49a601c2 Merge master.kernel.org:/home/rmk/linux-2.6-arm-smp 2005-07-29 09:47:08 -07:00
Jeff Dike 6f313b1233 [PATCH] uml: vm86 compile fix
We added an include of asm/vm86.h in include/asm-i386/ptrace.h.  Since UML
includes the underlying arch's ptrace.h, it needs an asm/vm86.h in order to
build.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-28 21:46:03 -07:00
Jesse Millan 8d224d32c2 [PATCH] x86_64: Fix gcc 4 warning in sched_find_first_bit
This patch eliminates the GCC4 warning on the x86_64 platform:

kernel/sched.c:1824: warning: control may reach end of non-void function
'sched_find_first_bit' being inlined.

The change follows the lead of others, i.e.  it is guaranteed that at least
one of b[0], b[1], or b[2] will have a bit set and evaluate to true.  That
being said, GCC4.0.0 notices that the code flow does not return anything if
b[0], b[1] and b[2] are not true.  Since we know better, if it's not b[0] or
b[1], it has to be b[2].

Signed-off-by: Jesse Millan <jessem@cs.pdx.edu>
Signed-off-by: Domen Puncer <domen@coderock.org>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-28 21:46:02 -07:00
Andi Kleen ed6b676ca8 [PATCH] x86_64: Switch to the interrupt stack when running a softirq in local_bh_enable()
This avoids some potential stack overflows with very deep softirq callchains.
i386 does this too.

TOADD CFI annotation

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-28 21:46:02 -07:00
Andi Kleen b6a68a16dc [PATCH] x86_64: Turn BUG data into valid instruction
This avoids confusing the disassembler. Costs 2 bytes per BUG.

Thanks to Suresh Siddha and Jan Beulich for suggesting suitable instructions.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-28 21:46:01 -07:00
Andi Kleen 17158d17aa [PATCH] x86_64: Fix incorrectly defined MSR_K8_SYSCFG
Harmless because the kernel didn't use it.  Noticed by Travis Betak

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-28 21:46:00 -07:00
Andi Kleen ca4e6b7402 [PATCH] x86_64: Fix some typos in system.h comments
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-28 21:46:00 -07:00
Andi Kleen 6391ad0aa4 [PATCH] x86_64: Remove obsolete eat_key prototype
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-28 21:45:59 -07:00
Andi Kleen d970a52180 [PATCH] x86_64: Fix some comments in tlbflush.h
Were either outdated or misleading.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-28 21:45:59 -07:00
Andi Kleen a940199f20 [PATCH] x86_64: Some cleanup in setup64.c
Minor cleanup.

Move things into their include files, remove obsolete includes, fix
indentation, remove obsolete special cases etc.

I also added the per cpu section to asm-generic/sections.h and fixed
init/main.c to use it.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-28 21:45:58 -07:00
Andi Kleen 5b943fbfaf [PATCH] x86_64: i386/x86_64: remove prototypes for not existing functions in smp.h
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-28 21:45:58 -07:00
Andi Kleen 74f0629397 [PATCH] x86_64: Use for_each_cpu_mask for clustered IPI flush
Makes it slightly more efficient.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-28 21:45:57 -07:00
Russell King e7ec02938d [ARM SMP] Fix another ARMv6 bitop problem
We sometimes forgot to check whether the exclusive store succeeded.
Ensure that we always check.  Also ensure that we always use the
out of line versions, since the inline versions are not SMP safe.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-07-28 20:36:26 +01:00
Linus Torvalds 2ac6608c41 Revert broken "statement with no effect" warning fix
It may shut up gcc, but it also incorrectly changes the semantics of the
smp_call_function() helpers.

You can fix the warning other ways if you are interested (create another
inline function that takes no arguments and returns zero), but
preferably gcc just shouldn't complain about unused return values from
statement expressions in the first place.
2005-07-28 10:34:47 -07:00
Linus Torvalds 7b70888a19 Merge master.kernel.org:/pub/scm/linux/kernel/git/perex/alsa 2005-07-28 08:41:58 -07:00
Steven Rostedt cd85c8b445 [PATCH] speed up on find_first_bit for i386 (let compiler do the work)
Avoid using "rep scas", just let the compiler select a sequence of
regular instructions.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-28 08:40:31 -07:00
Richard Henderson 79a8810221 [PATCH] alpha: fix "statement with no effect" warnings
Apparently gcc 4.0 complains about "({ 0; });", which leads to -Werror
breakage in one of the alpha oprofile modules.

One might could argue that this is a gcc bug, in that statement-expressions
should be considered to be function-like rather than statement-like for the
purposes of this warning.  But it's just as easy to use an inline function
in the first place, side-stepping the issue.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-28 08:39:02 -07:00
Jaroslav Kysela 0a97af41b0 [ALSA] version 1.0.9b 2005-07-28 15:50:42 +02:00
Victor Fusco 5a0f217d96 [ALSA] sound/core Fix the sparse warning 'implicit cast to nocast type'
Memalloc module,ALSA Core,Instrument layer
Fix the sparse warning 'implicit cast to nocast type'

File/Subsystem:sound/core

Signed-off-by: Victor Fusco <victor@cetuc.puc-rio.br>
Signed-off-by: Domen Puncer <domen@coderock.org>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
2005-07-28 12:22:44 +02:00
James Courtier-Dutton e66bc8b2a7 [ALSA] emu10k1: Add module option uint subsystem.
EMU10K1/EMU10K2 driver
It allows the user to force the snd-emu10k1 module to think the user
has a particular sound card. Useful if their particular sound card
is not yet recognised.

Signed-off-by: James Courtier-Dutton <James@superbug.co.uk>
2005-07-28 12:22:00 +02:00
Henrik Kretzschmar d5750f6785 [ALSA] cleanup and typo-correction
ALSA Core
This patch changes, adds and remove some comments, which will
make now more sense and fit on a 80-char line. It also changes
the order of snd_power_wait() to make the file more readable.
It removes the device.c comment in front of _snd_minor,
cause snd_minor has nothing to do with device.c.
The both typos in the kernel-docs were corrected too.

Signed-off-by: Henrik Kretzschmar <henne@nachtwindheim.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2005-07-28 12:09:46 +02:00
Richard Henderson 41c018b7ec [PATCH] new alpha syscalls
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-27 18:24:24 -07:00
Linus Torvalds 340d10e472 Merge master.kernel.org:/pub/scm/linux/kernel/git/davem/sparc-2.6 2005-07-27 17:09:10 -07:00
Linus Torvalds 96fad28a78 Merge master.kernel.org:/pub/scm/linux/kernel/git/aegl/linux-2.6 2005-07-27 16:37:03 -07:00
Jesper Juhl 77933d7276 [PATCH] clean up inline static vs static inline
`gcc -W' likes to complain if the static keyword is not at the beginning of
the declaration.  This patch fixes all remaining occurrences of "inline
static" up with "static inline" in the entire kernel tree (140 occurrences in
47 files).

While making this change I came across a few lines with trailing whitespace
that I also fixed up, I have also added or removed a blank line or two here
and there, but there are no functional changes in the patch.

Signed-off-by: Jesper Juhl <juhl-lkml@dif.dk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-27 16:26:20 -07:00
Adrian Bunk 82ee3e6fa3 [PATCH] drivers/media/video/tveeprom.c: possible cleanups
This patch contains the following possible cleanups:
- make two needlessly global structs static
- #if 0 the EXPORT_SYMBOL'ed but unused function tveeprom_dump

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-27 16:26:15 -07:00
Ralf Baechle e5c2d74917 [PATCH] serial_core whitespace fix
Use tabs for formatting like anywhere else in this file.

Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-27 16:26:09 -07:00
Olaf Hering 44456d37b5 [PATCH] turn many #if $undefined_string into #ifdef $undefined_string
turn many #if $undefined_string into #ifdef $undefined_string to fix some
warnings after -Wno-def was added to global CFLAGS

Signed-off-by: Olaf Hering <olh@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-27 16:26:08 -07:00
Andreas Gruenbacher 8c52ab42c1 [PATCH] mbcache: Remove unused mb_cache_shrink parameter
The cache parameter to mb_cache_shrink isn't used.  We may as well remove
it.

Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-27 16:26:07 -07:00
Peter Staubach c293621bbf [PATCH] stale POSIX lock handling
I believe that there is a problem with the handling of POSIX locks, which
the attached patch should address.

The problem appears to be a race between fcntl(2) and close(2).  A
multithreaded application could close a file descriptor at the same time as
it is trying to acquire a lock using the same file descriptor.  I would
suggest that that multithreaded application is not providing the proper
synchronization for itself, but the OS should still behave correctly.

SUS3 (Single UNIX Specification Version 3, read: POSIX) indicates that when
a file descriptor is closed, that all POSIX locks on the file, owned by the
process which closed the file descriptor, should be released.

The trick here is when those locks are released.  The current code releases
all locks which exist when close is processing, but any locks in progress
are handled when the last reference to the open file is released.

There are three cases to consider.

One is the simple case, a multithreaded (mt) process has a file open and
races to close it and acquire a lock on it.  In this case, the close will
release one reference to the open file and when the fcntl is done, it will
release the other reference.  For this situation, no locks should exist on
the file when both the close and fcntl operations are done.  The current
system will handle this case because the last reference to the open file is
being released.

The second case is when the mt process has dup(2)'d the file descriptor.
The close will release one reference to the file and the fcntl, when done,
will release another, but there will still be at least one more reference
to the open file.  One could argue that the existence of a lock on the file
after the close has completed is okay, because it was acquired after the
close operation and there is still a way for the application to release the
lock on the file, using an existing file descriptor.

The third case is when the mt process has forked, after opening the file
and either before or after becoming an mt process.  In this case, each
process would hold a reference to the open file.  For each process, this
degenerates to first case above.  However, the lock continues to exist
until both processes have released their references to the open file.  This
lock could block other lock requests.

The changes to release the lock when the last reference to the open file
aren't quite right because they would allow the lock to exist as long as
there was a reference to the open file.  This is too long.

The new proposed solution is to add support in the fcntl code path to
detect a race with close and then to release the lock which was just
acquired when such as race is detected.  This causes locks to be released
in a timely fashion and for the system to conform to the POSIX semantic
specification.

This was tested by instrumenting a kernel to detect the handling locks and
then running a program which generates case #3 above.  A dangling lock
could be reliably generated.  When the changes to detect the close/fcntl
race were added, a dangling lock could no longer be generated.

Cc: Matthew Wilcox <willy@debian.org>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-27 16:26:06 -07:00
Heiko Carstens 46ee058cdb [PATCH] s390: atomic64 inline functions
The atomic64 primitives are supposed to have 64-bit parameters instead of int.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-27 16:26:04 -07:00
Martin Schwidefsky afff7e2b3b [PATCH] s390: find_next_{zero}_bit fixes
The find_next_{zero}_bit primitives on s390* should never return a bit number
bigger then the bit field size.  In the case of a bitfield that doesn't end on
a word boundary, an offset that makes the search start at the last word of the
bit field and the last word doesn't contain any zero/one bits the search is
continued with a call to find_first_bit with a negative size.  The search
normally ends pretty quickly because the words following the bit field contain
a mix of zeros and ones.  But the bit number that is returned in this case is
too big.

To fix this and additional if to check for this case is needed.  To make the
code easier to read I removed the assembler parts from the
find_next_{zero}_bit functions, the C-ified code is as good.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-27 16:26:04 -07:00
Martin Schwidefsky 951f22d5b1 [PATCH] s390: spin lock retry
Split spin lock and r/w lock implementation into a single try which is done
inline and an out of line function that repeatedly tries to get the lock
before doing the cpu_relax().  Add a system control to set the number of
retries before a cpu is yielded.

The reason for the spin lock retry is that the diagnose 0x44 that is used to
give up the virtual cpu is quite expensive.  For spin locks that are held only
for a short period of time the costs of the diagnoses outweights the savings
for spin locks that are held for a longer timer.  The default retry count is
1000.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-27 16:26:04 -07:00