Move the initial hrtimers.txt document to the new directory
"Documentation/hrtimers"
Add design notes for the high resolution timer and dynamic tick functionality.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Reintroduce ktimers feature "optimized away" by the ktimers review process:
remove the curr_timer pointer from the cpu-base and use the hrtimer state.
No functional changes.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Reintroduce ktimers feature "optimized away" by the ktimers review process:
multiple hrtimer states to enable the running of hrtimers without holding the
cpu-base-lock.
(The "optimized" rbtree hack carried only 2 states worth of information and we
need 4 for high resolution timers and dynamic ticks.)
No functional changes.
Build-fixes-from: Andrew Morton <akpm@osdl.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Improve kernel/hrtimers.c locking: use a per-CPU base with a lock to control
locking of all clocks belonging to a CPU. This simplifies code that needs to
lock all clocks at once. This makes life easier for high-res timers and
dyntick.
No functional changes.
[ optimization change from Andrew Morton <akpm@osdl.org> ]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- hrtimers did not use the hrtimer_restart enum and relied on the implict
int representation. Fix the prototypes and the functions using the enums.
- Use seperate name spaces for the enumerations
- Convert hrtimer_restart macro to inline function
- Add comments
No functional changes.
[akpm@osdl.org: fix input driver]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For CONFIG_NO_HZ we need to calculate the next timer wheel event based on a
given jiffie value. Extend the existing code to allow the extra 'now'
argument. Provide a compability function for the existing implementations to
call the function with now == jiffies. (This also solves the racyness of the
original code vs. jiffies changing during the iteration.)
No functional changes to existing users of this infrastructure.
[ remove WARN_ON() that triggered on s390, by Carsten Otte <cotte@de.ibm.com> ]
[ made new helper static, Adrian Bunk <bunk@stusta.de> ]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When searching for the next pending timer in the timer wheel we need to take
the cascade into account. The current code has several problems:
1. it looks into the previous cascade
2. it ignores a pending cascade
3. it ignores multiple cascades
Change the cascade lookup, so it calculates the array index from the point of
the next cascade and always look at the cascade buckets, when the cascade is
pending, i.e. gets executed in the next timer softirq. When multiple
cascades are pending, then lookup the next buckets too.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Uninline irq_enter(). [dynticks adds more stuff to it]
No functional changes.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The Geode can safely use the TSC for highres, since:
1) Does not support frequency scaling,
2) The TSC _does_ count when the CPU is halted. Furthermore, the Geode
supports a mode called "suspension on halt", where Suspend mode (which
interacts with the power management states) is entered. TSC counting
during suspend mode is controlled by bit 8 of the Bus Controller
Configuration Register #0 (thanks Tom!).
3) no SMP :)
Check if "RTSC counts during suspension" and remove the requirement for
verification, so the clocksource code can safely select it as an timesource
for the highres timers subsystem.
Signed-off-by: Marcelo Tosatti <marcelo@kvack.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The TSC needs to be verified against another clocksource. Instead of using
hardwired assumptions of available hardware, provide a generic verification
mechanism. The verification uses the best available clocksource and handles
the usability for high resolution timers / dynticks of the clocksource which
needs to be verified.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The clocksource code allows direct updates of the rating of a given
clocksource now. Change TSC unstable tracking to use this interface and
remove the update callback.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fixup the is_contionous replacement by a flag field.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fixup the is_contionous replacement by a flag field.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fixup the is_contionous replacement by a flag field.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fixup the is_contionous replacement by a flag field.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Using a flag filed allows to encode more than one information into a variable.
Preparatory patch for the generic clocksource verification.
[mingo@elte.hu: convert vmitime.c to the new clocksource flag]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
make the TSC synchronization code more robust, and unify it between x86_64 and
i386.
The biggest change is the removal of the 'fix up TSCs' code on x86_64 and
i386, in some rare cases it was /causing/ time-warps on SMP systems.
The new code only checks for TSC asynchronity - and if it can prove a
time-warp (if it can observe the TSC going backwards when going from one CPU
to another within a critical section), then the TSC clock-source is turned
off.
The TSC synchronization-checking code also got moved into a separate file.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Enqueue clocksources in rating order to make selection of the clocksource
easier. Also check the match with an user override at enqueue time.
Preparatory patch for the generic clocksource verification.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The delayed work code in arch/i386/kernel/tsc.c is an unused leftover of the
GTOD conversion. Remove it.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Prevent timeout overflow if timer ticks are behind jiffies (due to high
softirq load or due to dyntick), by limiting the valid timeout range to
MAX_LONG/2.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix multiple conversion bugs in msecs_to_jiffies().
The main problem is that this condition:
if (m > jiffies_to_msecs(MAX_JIFFY_OFFSET))
overflows if HZ is smaller than 1000!
This change is user-visible: for HZ=250 SUS-compliant poll()-timeout
value of -20 is mistakenly converted to 'immediate timeout'.
(The new dyntick code also triggered this, that's how we noticed.)
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are loads of fat functions hidden in jiffies.h. Uninline them. No code
changes.
[jeremy@goop.org: export fix]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Distangle the NTP update from HZ. This is necessary for dynamic tick enabled
kernels.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Provide funtions to:
- check, whether an interrupt can set the affinity
- pin the interrupt to a given cpu
Necessary for the ability to setup clocksources more flexible (e.g. use the
different HPET channels per CPU)
[akpm@osdl.org: alpha build fix]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a flag so we can prevent the irq balancing of an interrupt. Move the
bits, so we have room for more :)
Necessary for the ability to setup clocksources more flexible (e.g. use the
different HPET channels per CPU)
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
arch/i386/kernel/built-in.o: In function `vmi_stop_hz_timer':
: undefined reference to `next_timer_interrupt'
If CONFIG_NO_HZ, next_timer_interrupt() doesn't exist (and presumably doesn't
make sense).
Perhaps VMI shouildn't be playing with timer internals at this level.
Cc: Zachary Amsden <zach@vmware.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A previous cleanup misused need_poll, which had a fairly broken interface.
It implemented a growable array, changing the used elements count itself,
but leaving it up to the caller to fill in the actual elements, including
the entire array if the array had to be reallocated. This worked because
the previous users were switching between two such structures, and the
elements were copied from the inactive array to the active array after
making sure the active array had enough room.
maybe_sigio_broken was made to use need_poll, but it was operating on a
single array, so when the buffer was reallocated, the previous contents
were lost.
This patch makes need_poll implement more sane semantics. It merely
assures that the array is of the proper size and that the contents are
preserved. It is up to the caller to adjust the used elements count and to
ensure that the proper elements are resent.
This manifested itself as a hang in 2.6.20 as the uninitialized buffer
convinced UML that one of its own file descriptors didn't support SIGIO and
needed to be watched by poll in a separate thread. The result was an
interrupt flood as control traffic over this descriptor sparked interrupts,
which resulted in more control traffic, ad nauseum.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If prepare_write or commit_write return AOP_TRUNCATED_PAGE we jump to
"retry" label and than if find_or_create_page() failed function return
incorrect error code.
Signed-off-by: Dmitriy Monakhov <dmonakhov@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It appears that the pcim_iomap_regions() function doesn't get the error
handling right. It BUGs early at boot with a backtrace along the lines of:
ahci_init
pci_register_driver
driver_register
[...]
ahci_init_one
pcim_iomap_region
pcim_iounmap
The following patch allows me to boot. Only the if(mask..) continue;
part fixes the problem actually, the gotos where changed so that we
don't try to unmap something we couldn't map anyway.
Signed-off-by: Frederik Deweerdt <frederik.deweerdt@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Tejun Heo <htejun@gmail.com>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Small updates to the GPIO documentation, addressing feedback and
fixing a few spelling errors.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This modifies drivers/ata/sata_vsc.c to only set the cache line size
to 0x80 if the default value is zero. Apparently zero isn't allowed
due to a bug in the chip, but I've found performance is much better
with the (non-zero) default instead of 0x80.
[note1: "default" means BIOS-programmed value, in this context -jgarzik]
[note2: superfluous braces were removed from the patch -jg]
Signed-off-by: Nate Dailey <nate.dailey@stratus.com>
Signed-off-by: Jeremy Higdon <jeremy@sgi.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
ADMA-capable controllers provide a bit in the status register that appears
to indicate that the controller detected an SError condition. Update sata_nv
to detect this and trigger error handling in order to handle the fault.
Signed-off-by: Robert Hancock <hancockr@shaw.ca>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
The hald media changed polling does really confuse things.
Noone knows why the delays are needed, but they give us access to the CD.
An udelay(50) will give reliable access to the drive, but there is still
one (or more) EH reset. The drive works without EH resets with udelay(100).
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
If an ATA drive uses legacy mode, ata driver will choose 14 and 15
as the fixed irq number. On ia64 platform, such numbers are GSI and
should be converted to irq vector.
Below patch against kernel 2.6.20 fixes it.
Signed-off-by: Zhang Yanmin <yanmin.zhang@intel.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Some devices chock if Feature is not clear when IDENTIFY is issued.
Set ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE for IDENTIFY such that whole
TF is cleared when reading ID data.
Kudos to Art Haas for testing various futile patches over several
months and Mark Lord for pointing out the fix.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Art Haas <ahaas@airmail.net>
Cc: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
This is the first preparation to doing the !IORDY cases properly. Further
diffs will then add the needed logic to do it right.
Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: Tejun Heo <htejun@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
The 80c wire bit is bit 13, not 14. Bit 14 is always 1 if word93 is
implemented. This increases the chance of incorrect wire detection
especially because host side cable detection is often unreliable and
we sometimes soley depend on drive side cable detection. Fix the test
and add word93 validity check.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
This patch updates the sata_promise driver to use new-style
libata error handling for 20619 (TX4000) chips. sata_promise
already uses new EH for the other chips it supports, so the
patch is quite simple:
* remove ->phy_reset and ->eng_timeout ops from pdc_pata_ops,
and instead bind ->freeze, ->thaw, ->error_handler, and
->post_internal_cmd to existing new EH functions
* drop ATA_FLAG_SRST from board_20619's flags
* remove now unused pdc_pata_phy_reset() and pdc_eng_timeout()
Tested on a TX4000 with both modern working disks and old/quirky
disks. Also used a CD-RW drive to test reading and writing CDs.
Signed-off-by: Mikael Pettersson <mikpe@it.uu.se>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
This patch fixes an oversight which caused sata_promise to
not perform cable detection on the TX2plus chips' PATA ports.
Signed-off-by: Mikael Pettersson <mikpe@it.uu.se>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Paper bag time. Thanks to Randy for noticing that I didn't actually assign
'present' to anything.
Unfortunately my original patch passed the few simple test cases I gave it,
purely by coincidence.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix mincore-anon patch to compile with CONFIG_SWAP=n
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This tidies up some of the rts7751r2d mess and gets it booting
again. Update the defconfig, too.
Signed-off-by: Masayuki Hosokawa <hosokawa@ace-jp.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Since the security checks are applied on each read and write of a sysctl file,
just like they are applied when calling sys_sysctl, they are redundant on the
standard VFS constructs. Since it is difficult to compute the security labels
on the standard VFS constructs we just mark the sysctl inodes in proc private
so selinux won't even bother with them.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
