07 Jan, 2012
1 commit
-
This resolves the conflict in the arch/arm/mach-s3c64xx/s3c6400.c file,
and it fixes the build error in the arch/x86/kernel/microcode_core.c
file, that the merge did not catch.The microcode_core.c patch was provided by Stephen Rothwell
who was invaluable in the merge issues involved
with the large sysdev removal process in the driver-core tree.Signed-off-by: Greg Kroah-Hartman
19 Dec, 2011
1 commit
-
Fix various KernelDoc build warnings.
Signed-off-by: Kusanagi Kouichi
Cc: John Stultz
Link: http://lkml.kernel.org/r/20111219091320.0D5AF6FC03D@msa105.auone-net.jp
Signed-off-by: Ingo Molnar
15 Dec, 2011
1 commit
-
After all sysdev classes are ported to regular driver core entities, the
sysdev implementation will be entirely removed from the kernel.Cc: John Stultz
Cc: Thomas Gleixner
Signed-off-by: Kay Sievers
Signed-off-by: Greg Kroah-Hartman
02 Dec, 2011
1 commit
-
In order to leave a margin of 12.5% we should >> 3 not >> 5.
CC: stable@kernel.org
Signed-off-by: Yang Honggang (Joseph)
[jstultz: Modified commit subject]
Signed-off-by: John Stultz
11 Nov, 2011
1 commit
-
For some frequencies, the clocks_calc_mult_shift() function will
unfortunately select mult values very close to 0xffffffff. This
has the potential to overflow when NTP adjusts the clock, adding
to the mult value.This patch adds a clocksource.maxadj value, which provides
an approximation of an 11% adjustment(NTP limits adjustments to
500ppm and the tick adjustment is limited to 10%), which could
be made to the clocksource.mult value. This is then used to both
check that the current mult value won't overflow/underflow, as
well as warning us if the timekeeping_adjust() code pushes over
that 11% boundary.v2: Fix max_adjustment calculation, and improve WARN_ONCE
messages.v3: Don't warn before maxadj has actually been set
CC: Yong Zhang
CC: David Daney
CC: Thomas Gleixner
CC: Chen Jie
CC: zhangfx
CC: stable@kernel.org
Reported-by: Chen Jie
Reported-by: zhangfx
Tested-by: Yong Zhang
Signed-off-by: John Stultz
13 Sep, 2011
1 commit
-
KGDB needs to trylock watchdog_lock when trying to reset the
clocksource watchdog after the system has been stopped to avoid a
potential deadlock. When the trylock fails TSC usually becomes
unstable.We can be more clever by using an atomic counter and checking it in
the clocksource_watchdog callback. We restart the watchdog whenever
the counter is > 0 and only decrement the counter when we ran through
a full update cycle.Signed-off-by: Thomas Gleixner
Cc: John Stultz
Acked-by: Jason Wessel
Cc: Peter Zijlstra
Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1109121326280.2723@ionos
Signed-off-by: Thomas Gleixner
17 Jun, 2011
1 commit
-
The clocksource watchdog code is interruptible and it has been
observed that this can trigger false positives which disable the TSC.The reason is that an interrupt storm or a long running interrupt
handler between the read of the watchdog source and the read of the
TSC brings the two far enough apart that the delta is larger than the
unstable treshold. Move both reads into a short interrupt disabled
region to avoid that.Reported-and-tested-by: Vernon Mauery
Signed-off-by: Thomas Gleixner
Cc: stable@kernel.org
20 May, 2011
2 commits
-
unsigned long is not 64bit on 32bit machine.
Signed-off-by: Thomas Gleixner
-
…x/kernel/git/tip/linux-2.6-tip
* 'timers-clockevents-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86: hpet: Cleanup the clockevents init and register code
x86: Convert PIT to clockevents_config_and_register()
clockevents: Provide interface to reconfigure an active clock event device
clockevents: Provide combined configure and register function
clockevents: Restructure clock_event_device members
clocksource: Get rid of the hardcoded 5 seconds sleep time limit
clocksource: Restructure clocksource struct members
19 May, 2011
1 commit
-
Slow clocksources can have a way longer sleep time than 5 seconds and
even fast ones can easily cope with 600 seconds and still maintain
proper accuracy.Signed-off-by: Thomas Gleixner
Cc: John Stultz
Reviewed-by: Ingo Molnar
Link: http://lkml.kernel.org/r/%3C20110518210136.109811585%40linutronix.de%3E
05 May, 2011
1 commit
-
Christian Hoffmann reported that the command line clocksource override
with acpi_pm timer fails:Kernel command line: clocksource=acpi_pm
hpet clockevent registered
Switching to clocksource hpet
Override clocksource acpi_pm is not HRT compatible.
Cannot switch while in HRT/NOHZ mode.The watchdog code is what enables CLOCK_SOURCE_VALID_FOR_HRES, but we
actually end up selecting the clocksource before we enqueue it into
the watchdog list, so that's why we see the warning and fail to switch
to acpi_pm timer as requested. That's particularly bad when we want to
debug timekeeping related problems in early boot.Put the selection call last.
Reported-by: Christian Hoffmann
Signed-off-by: John Stultz
Cc: stable@kernel.org # 32...
Link: http://lkml.kernel.org/r/%3C1304558210.2943.24.camel%40work-vm%3E
Signed-off-by: Thomas Gleixner
16 Jan, 2011
1 commit
-
…linus' and 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
rcu: avoid pointless blocked-task warnings
rcu: demote SRCU_SYNCHRONIZE_DELAY from kernel-parameter status
rtmutex: Fix comment about why new_owner can be NULL in wake_futex_pi()* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, olpc: Add missing Kconfig dependencies
x86, mrst: Set correct APB timer IRQ affinity for secondary cpu
x86: tsc: Fix calibration refinement conditionals to avoid divide by zero
x86, ia64, acpi: Clean up x86-ism in drivers/acpi/numa.c* 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
timekeeping: Make local variables static
time: Rename misnamed minsec argument of clocks_calc_mult_shift()* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
tracing: Remove syscall_exit_fields
tracing: Only process module tracepoints once
perf record: Add "nodelay" mode, disabled by default
perf sched: Fix list of events, dropping unsupported ':r' modifier
Revert "perf tools: Emit clearer message for sys_perf_event_open ENOENT return"
perf top: Fix annotate segv
perf evsel: Fix order of event list deletion
14 Jan, 2011
1 commit
-
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (43 commits)
Documentation/trace/events.txt: Remove obsolete sched_signal_send.
writeback: fix global_dirty_limits comment runtime -> real-time
ppc: fix comment typo singal -> signal
drivers: fix comment typo diable -> disable.
m68k: fix comment typo diable -> disable.
wireless: comment typo fix diable -> disable.
media: comment typo fix diable -> disable.
remove doc for obsolete dynamic-printk kernel-parameter
remove extraneous 'is' from Documentation/iostats.txt
Fix spelling milisec -> ms in snd_ps3 module parameter description
Fix spelling mistakes in comments
Revert conflicting V4L changes
i7core_edac: fix typos in comments
mm/rmap.c: fix comment
sound, ca0106: Fix assignment to 'channel'.
hrtimer: fix a typo in comment
init/Kconfig: fix typo
anon_inodes: fix wrong function name in comment
fix comment typos concerning "consistent"
poll: fix a typo in comment
...Fix up trivial conflicts in:
- drivers/net/wireless/iwlwifi/iwl-core.c (moved to iwl-legacy.c)
- fs/ext4/ext4.hAlso fix missed 'diabled' typo in drivers/net/bnx2x/bnx2x.h while at it.
12 Jan, 2011
1 commit
-
The minsec argument to clocks_calc_mult_shift() is misnamed. It is used
to clamp the magnitude of the mult factor so that a multiplication with
any value in the given range won't overflow a 64 bit result. Let's
rename it to match the actual usage.Signed-off-by: Nicolas Pitre
Acked-by: John Stultz
LKML-Reference:
Signed-off-by: Thomas Gleixner
23 Dec, 2010
1 commit
-
Russell King reports:
| On the ARM dev boards, we have a 32-bit counter running at 24MHz. Calling
| clocks_calc_mult_shift(&mult, &shift, 24MHz, NSEC_PER_SEC, 60) gives
| us a multiplier of 2796202666 and a shift of 26.
|
| Over a large counter delta, this produces an error - lets take a count
| from 362976315 to 4280663372:
|
| (4280663372-362976315) * 2796202666 / 2^26 - (4280663372-362976315) * (1000/24)
| => -38.91872422891230269990
|
| Can we do better?
|
| (4280663372-362976315) * 2796202667 / 2^26 - (4280663372-362976315) * (1000/24)
| 19.45936211449532822051
|
| which is about twice as good as the 2796202666 multiplier.
|
| Looking at the equivalent divisions obtained, 2796202666 / 2^26 gives
| 41.66666665673255920410ns per tick, whereas 2796202667 / 2^26 gives
| 41.66666667163372039794ns. The actual value wanted is 1000/24 =
| 41.66666666666666666666ns.Fix this by ensuring we round to nearest when calculating the
multiplier.Signed-off-by: John Stultz
Tested-by: Santosh Shilimkar
Tested-by: Will Deacon
Tested-by: Mikael Pettersson
Tested-by: Eric Miao
Tested-by: Olof Johansson
Tested-by: Jamie Iles
Signed-off-by: Russell King
02 Nov, 2010
1 commit
-
"gadget", "through", "command", "maintain", "maintain", "controller", "address",
"between", "initiali[zs]e", "instead", "function", "select", "already",
"equal", "access", "management", "hierarchy", "registration", "interest",
"relative", "memory", "offset", "already",Signed-off-by: Uwe Kleine-König
Signed-off-by: Jiri Kosina
27 Jul, 2010
2 commits
-
To properly handle clocksources that change frequencies
at the clocksource->enable() point, this patch adds
a method that will update the clocksource's mult/shift and
max_idle_ns values.Signed-off-by: John Stultz
LKML-Reference:
Signed-off-by: Thomas Gleixner -
Now that all arches have been converted over to use generic time via
clocksources or arch_gettimeoffset(), we can remove the GENERIC_TIME
config option and simplify the generic code.Signed-off-by: John Stultz
LKML-Reference:
Signed-off-by: Thomas Gleixner
10 May, 2010
1 commit
-
How to pick good mult/shift pairs has always been difficult to
describe to folks writing clocksource drivers, since it requires
careful tradeoffs in adjustment accuracy vs overflow limits.Now, with the clocks_calc_mult_shift function, its much
easier. However, not many clocksources have converted to using that
function, and there is still the issue of the max interval length
assumption being made by each clocksource driver independently.So this patch simplifies the registration process by having
clocksources be registered with a hz/khz value and the registration
function taking care of setting mult/shift.This should take most of the confusion out of writing a clocksource
driver.Additionally it also keeps the shift size tradeoff (more accuracy vs
longer possible nohz times) centralized so the timekeeping core can
keep track of the assumptions being made.[ tglx: Coding style and comments fixed ]
Signed-off-by: John Stultz
LKML-Reference:
Signed-off-by: Thomas Gleixner
02 Mar, 2010
2 commits
-
Aaro Koskinen reported an issue in kernel.org bugzilla #15366, where
on non-GENERIC_TIME systems, accessing
/sys/devices/system/clocksource/clocksource0/current_clocksource
results in an oops.It seems the timekeeper/clocksource rework missed initializing the
curr_clocksource value in the !GENERIC_TIME case.Thanks to Aaro for reporting and diagnosing the issue as well as
testing the fix!Reported-by: Aaro Koskinen
Signed-off-by: John Stultz
Cc: Martin Schwidefsky
Cc: stable@kernel.org
LKML-Reference:
Signed-off-by: Thomas Gleixner -
* 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
posix-timers.c: Don't export local functions
clocksource: start CMT at clocksource resume
clocksource: add suspend callback
clocksource: add argument to resume callback
ntp: Cleanup xtime references in ntp.c
ntp: Make time_esterror and time_maxerror static
05 Feb, 2010
2 commits
-
Add a clocksource suspend callback. This callback can be used by the
clocksource driver to shutdown and perform any kind of late suspend
activities even though the clocksource driver itself is a non-sysdev
driver.One example where this is useful is to fix the sh_cmt.c platform driver
that today suspends using the platform bus and shuts down the clocksource
too early.With this callback in place the sh_cmt driver will suspend using the
clocksource and clockevent hooks and leave the platform device pm
callbacks unused.Signed-off-by: Magnus Damm
Cc: Paul Mundt
Cc: john stultz
Signed-off-by: Andrew Morton
Signed-off-by: Thomas Gleixner -
Pass the clocksource as an argument to the clocksource resume callback.
Needed so we can point out which CMT channel the sh_cmt.c driver shall
resume.Signed-off-by: Magnus Damm
Cc: john stultz
Cc: Paul Mundt
Signed-off-by: Andrew Morton
Signed-off-by: Thomas Gleixner
26 Jan, 2010
1 commit
-
commit 0f8e8ef7 (clocksource: Simplify clocksource watchdog resume
logic) introduced a potential kgdb dead lock. When the kernel is
stopped by kgdb inside code which holds watchdog_lock then kgdb dead
locks in clocksource_resume_watchdog().clocksource_resume_watchdog() is called from kbdg via
clocksource_touch_watchdog() to avoid that the clock source watchdog
marks TSC unstable after the kernel has been stopped.Solve this by replacing spin_lock with a spin_trylock and just return
in case the lock is held. Not resetting the watchdog might result in
TSC becoming marked unstable, but that's an acceptable penalty for
using kgdb.The timekeeping is anyway easily screwed up by kgdb when the system
uses either jiffies or a clock source which wraps in short intervals
(e.g. pm_timer wraps about every 4.6s), so we really do not have to
worry about that occasional TSC marked unstable side effect.The second caller of clocksource_resume_watchdog() is
clocksource_resume(). The trylock is safe here as well because the
system is UP at this point, interrupts are disabled and nothing else
can hold watchdog_lock().Reported-by: Jason Wessel
LKML-Reference:
Cc: kgdb-bugreport@lists.sourceforge.net
Cc: Martin Schwidefsky
Cc: John Stultz
Cc: Andrew Morton
Signed-off-by: Thomas Gleixner
10 Dec, 2009
1 commit
-
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (42 commits)
tree-wide: fix misspelling of "definition" in comments
reiserfs: fix misspelling of "journaled"
doc: Fix a typo in slub.txt.
inotify: remove superfluous return code check
hdlc: spelling fix in find_pvc() comment
doc: fix regulator docs cut-and-pasteism
mtd: Fix comment in Kconfig
doc: Fix IRQ chip docs
tree-wide: fix assorted typos all over the place
drivers/ata/libata-sff.c: comment spelling fixes
fix typos/grammos in Documentation/edac.txt
sysctl: add missing comments
fs/debugfs/inode.c: fix comment typos
sgivwfb: Make use of ARRAY_SIZE.
sky2: fix sky2_link_down copy/paste comment error
tree-wide: fix typos "couter" -> "counter"
tree-wide: fix typos "offest" -> "offset"
fix kerneldoc for set_irq_msi()
spidev: fix double "of of" in comment
comment typo fix: sybsystem -> subsystem
...
09 Dec, 2009
1 commit
-
* 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
timers, init: Limit the number of per cpu calibration bootup messages
posix-cpu-timers: optimize and document timer_create callback
clockevents: Add missing include to pacify sparse
x86: vmiclock: Fix printk format
x86: Fix printk format due to variable type change
sparc: fix printk for change of variable type
clocksource/events: Fix fallout of generic code changes
nohz: Allow 32-bit machines to sleep for more than 2.15 seconds
nohz: Track last do_timer() cpu
nohz: Prevent clocksource wrapping during idle
nohz: Type cast printk argument
mips: Use generic mult/shift factor calculation for clocks
clocksource: Provide a generic mult/shift factor calculation
clockevents: Use u32 for mult and shift factors
nohz: Introduce arch_needs_cpu
nohz: Reuse ktime in sub-functions of tick_check_idle.
time: Remove xtime_cache
time: Implement logarithmic time accumulation
14 Nov, 2009
3 commits
-
powerpc grew a new warning due to the type change of clockevent->mult.
The architectures which use parts of the generic time keeping
infrastructure tripped over my wrong assumption that
clocksource_register is only used when GENERIC_TIME=y.I should have looked and also I should have known better. These
renitent Gaul villages are racking my nerves. Some serious deprecating
is due.Signed-off-by: Thomas Gleixner
-
The dynamic tick allows the kernel to sleep for periods longer than a
single tick, but it does not limit the sleep time currently. In the
worst case the kernel could sleep longer than the wrap around time of
the time keeping clock source which would result in losing track of
time.Prevent this by limiting it to the safe maximum sleep time of the
current time keeping clock source. The value is calculated when the
clock source is registered.[ tglx: simplified the code a bit and massaged the commit msg ]
Signed-off-by: Jon Hunter
Cc: John Stultz
LKML-Reference:
Signed-off-by: Thomas Gleixner -
MIPS has two functions to calculcate the mult/shift factors for clock
sources and clock events at run time. ARM needs such functions as
well.Implement a function which calculates the mult/shift factors based on
the frequencies to which and from which is converted. The function
also has a parameter to specify the minimum conversion range in
seconds. This range is guaranteed not to produce a 64bit overflow when
a value is multiplied with the calculated mult factor. The larger the
conversion range the less becomes the conversion accuracy.Provide two inline wrappers which handle clock events and clock
sources. For clock events the "from" frequency is nano seconds per
second which corresponds to 1GHz and "to" is the device frequency. For
clock sources "from" is the device frequency and "to" is nano seconds
per second.Signed-off-by: Thomas Gleixner
Tested-by: Mikael Pettersson
Acked-by: Ralf Baechle
Acked-by: Linus Walleij
Cc: John Stultz
LKML-Reference:
12 Nov, 2009
1 commit
-
Noticed by Thomas GLeixner.
Signed-off-by: David S. Miller
09 Nov, 2009
1 commit
-
This patch was generated by
git grep -E -i -l 's(le|el)ct' | xargs -r perl -p -i -e 's/([Ss])(le|el)ct/$1elect/
with only skipping net/netfilter/xt_SECMARK.c and
include/linux/netfilter/xt_SECMARK.h which have a struct member called
selctx.Signed-off-by: Uwe Kleine-König
Signed-off-by: Jiri Kosina
25 Sep, 2009
1 commit
-
git commit 75c5158f70c065b9 converted the clocksource spinlock to a
mutex. This causes the following BUG:BUG: sleeping function called from invalid context at
kernel/mutex.c:280 in_atomic(): 0, irqs_disabled(): 1, pid: 2473,
name: pm-suspend 2 locks held by pm-suspend/2473:
#0: (&buffer->mutex){......}, at: []
sysfs_write_file+0x3c/0x137
#1: (pm_mutex){......}, at: []
enter_state+0x39/0x130 Pid: 2473, comm: pm-suspend Not tainted 2.6.31
#1 Call Trace:
[] ? __debug_show_held_locks+0x22/0x24
[] __might_sleep+0x107/0x10b
[] mutex_lock_nested+0x25/0x43
[] clocksource_resume+0x1c/0x60
[] timekeeping_resume+0x1e/0x1c8
[] __sysdev_resume+0x25/0xcf
[] sysdev_resume+0x6d/0xae
[] suspend_devices_and_enter+0x12b/0x1af
[] enter_state+0xdf/0x130
[] state_store+0xb6/0xd3
[] kobj_attr_store+0x17/0x19
[] sysfs_write_file+0xfb/0x137
[] vfs_write+0xae/0x10b
[] ? __up_read+0x1a/0x7f
[] sys_write+0x4a/0x6e
[] system_call_fastpath+0x16/0x1bclocksource_resume is called early in the resume process, there is
only one cpu, no processes are running and the interrupts are
disabled. It is therefore possible to resume the clocksources
without taking the clocksource mutex.Reported-by: Xiaotian Feng
Signed-off-by: Martin Schwidefsky
Tested-by: Michal Schmidt
Cc: Xiaotian Feng
Cc: John Stultz
LKML-Reference:
Signed-off-by: Ingo Molnar
15 Sep, 2009
2 commits
-
The down rating of clock sources in the early boot process via the
clock source watchdog mechanism can happen way before the per cpu
event queues are initialized. This leads to a boot crash on x86 when
the TSC is marked unstable in the SMP bring up.The selection of a clock source for time keeping happens in the late
boot process so we can safely delay the list manipulation until
clocksource_done_booting() is called.Signed-off-by: Thomas Gleixner
LKML-Reference:
Cc: Martin Schwidefsky -
The callers of clocksource_select must hold clocksource_mutex to
protect the clocksource_list.Signed-off-by: Thomas Gleixner
LKML-Reference:
Cc: Martin Schwidefsky
12 Sep, 2009
1 commit
-
The watchdog timer is started after the watchdog clocksource
and at least one watched clocksource have been registered. The
clocksource work element watchdog_work is initialized just
before the clocksource timer is started. This is too late for
the clocksource_mark_unstable call from native_cpu_up. To fix
this use a static initializer for watchdog_work.This resolves a boot crash reported by multiple people.
Signed-off-by: Martin Schwidefsky
Cc: Jens Axboe
Cc: John Stultz
LKML-Reference:
Signed-off-by: Ingo Molnar
29 Aug, 2009
1 commit
-
Martin Schwidefsky analyzed it:
To register a clocksource the clocksource_mutex is acquired and if
necessary timekeeping_notify is called to install the clocksource as
the timekeeper clock. timekeeping_notify uses stop_machine which needs
to take cpu_add_remove_lock mutex.
Starting a new cpu is done with the cpu_add_remove_lock mutex held.
native_cpu_up checks the tsc of the new cpu and if the tsc is no good
clocksource_change_rating is called. Which needs the clocksource_mutex
and the deadlock is complete.The solution is to replace the TSC via the clocksource watchdog
mechanism. Mark the TSC as unstable and schedule the watchdog work so
it gets removed in the watchdog thread context.Signed-off-by: Thomas Gleixner
LKML-Reference:
Cc: Martin Schwidefsky
Cc: John Stultz
19 Aug, 2009
2 commits
-
stop_machine from a multithreaded workqueue is not allowed because
of a circular locking dependency between cpu_down and the workqueue
execution. Use a kernel thread to do the clocksource downgrade.Signed-off-by: Martin Schwidefsky
Cc: Peter Zijlstra
Cc: john stultz
LKML-Reference:
Signed-off-by: Thomas Gleixner -
Martin pointed out that commit 6ea41d2529 (clocksource: Call
clocksource_change_rating() outside of watchdog_lock) has a
theoretical reference count problem. The calls to
clocksource_change_rating() are now done outside of the clocksource
mutex and outside of the watchdog lock. A concurrent
clocksource_unregister() could remove the clock.Split out the code which changes the rating from
clocksource_change_rating() into __clocksource_change_rating().Protect the clocksource_watchdog_work() code sequence with the
clocksource_mutex() and call __clocksource_change_rating().LKML-Reference:
Signed-off-by: Thomas Gleixner
Cc: Martin Schwidefsky
15 Aug, 2009
2 commits
-
The changes to the watchdog logic introduced a lock inversion between
watchdog_lock and clocksource_mutex. Change the rating outside of
watchdog_lock to avoid it.Signed-off-by: Thomas Gleixner
-
update_wall_time calls change_clocksource HZ times per second to check
if a new clock source is available. In close to 100% of all calls
there is no new clock. Replace the tick based check by an update done
with stop_machine.Signed-off-by: Martin Schwidefsky
Cc: Ingo Molnar
Acked-by: John Stultz
Cc: Daniel Walker
LKML-Reference:
Signed-off-by: Thomas Gleixner