- 16 Feb, 2007 40 commits
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Thomas Gleixner authored
The local apic timer calibration has two problem cases: 1. The calibration is based on readout of the PIT/HPET timer to detect the wrap of the periodic tick. It happens that a box gets stuck in the calibration loop due to a PIT with a broken readout function. 2. CoreDuo boxen show a sporadic PIT runs too slow defect, which results in a wrong lapic calibration. The PIT goes back to normal operation once the lapic timer is switched to periodic mode. Both are existing and unfixed problems in the current upstream kernel and prevent certain laptops and other systems from booting Linux. Rework the code to address both problems: - Make the calibration interrupt driven. This removes the wait_timer_tick magic hackery from lapic.c and time_hpet.c. The clockevents framework allows easy substitution of the global tick event handler for the calibration. This is more accurate than monitoring jiffies. At this point of the boot process, nothing disturbes the interrupt delivery, so the results are very accurate. - Verify the calibration against the PM timer, when available by using the early access function. When the measured calibration period is outside of an one percent window, then the lapic timer calibration is adjusted to the pm timer result. - Verify the calibration by running the lapic timer with the calibration handler. Disable lapic timer in case of deviation. This also removes the "synchronization" of the local apic timer to the global tick. This synchronization never worked, as there is no way to synchronize PIT(HPET) and local APIC timer. The synchronization by waiting for the tick just alignes the local APIC timer for the first events, but later the events drift away due to the different clocks. Removing the "sync" is just randomizing the asynchronous behaviour at setup time. Signed-off-by:
Thomas Gleixner <tglx@linutronix.de> Signed-off-by:
Ingo Molnar <mingo@elte.hu> Cc: Zachary Amsden <zach@vmware.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Rohit Seth <rohitseth@google.com> Cc: Andi Kleen <ak@suse.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>
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Thomas Gleixner authored
Add clockevent drivers for i386: lapic (local) and PIT/HPET (global). Update the timer IRQ to call into the PIT/HPET driver's event handler and the lapic-timer IRQ to call into the lapic clockevent driver. The assignement of timer functionality is delegated to the core framework code and replaces the compile and runtime evalution in do_timer_interrupt_hook() Use the clockevents broadcast support and implement the lapic_broadcast function for ACPI. No changes to existing functionality. [ kdump fix from Vivek Goyal <vgoyal@in.ibm.com> ] [ fixes based on review feedback from Arjan van de Ven <arjan@infradead.org> ] Cleanups-from: Adrian Bunk <bunk@stusta.de> Build-fixes-from: Andrew Morton <akpm@osdl.org> Signed-off-by:
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Thomas Gleixner authored
With Ingo Molnar <mingo@elte.hu> Add functions to provide dynamic ticks and high resolution timers. The code which keeps track of jiffies and handles the long idle periods is shared between tick based and high resolution timer based dynticks. The dyntick functionality can be disabled on the kernel commandline. Provide also the infrastructure to support high resolution timers. Signed-off-by:
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Thomas Gleixner authored
With Ingo Molnar <mingo@elte.hu> Add broadcast functionality, so per cpu clock event devices can be registered as dummy devices or switched from/to broadcast on demand. The broadcast function distributes the events via the broadcast function of the clock event device. This is primarily designed to replace the switch apic timer to / from IPI in power states, where the apic stops. Signed-off-by:
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Thomas Gleixner authored
With Ingo Molnar <mingo@elte.hu> The tick-management code is the first user of the clockevents layer. It takes clock event devices from the clock events core and uses them to provide the periodic tick. Signed-off-by:
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Thomas Gleixner authored
Architectures register their clock event devices, in the clock events core. Users of the clockevents core can get clock event devices for their use. The clockevents core code provides notification mechanisms for various clock related management events. This allows to control the clock event devices without the architectures having to worry about the details of function assignment. This is also a preliminary for high resolution timers and dynamic ticks to allow the core code to control the clock functionality without intrusive changes to the architecture code. [Fixes-by: Ingo Molnar <mingo@elte.hu>] Signed-off-by:
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Thomas Gleixner authored
The apic code is quite unstructured and missing a lot of comments. - Restructure the code into helper functions, timer, setup/shutdown, interrupt and power management blocks. - Fixup comments. - Namespace fixups - Inline helpers for version and is_integrated - Combine the ack_bad_irq functions No functional changes. Signed-off-by:
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Thomas Gleixner authored
Allow early access to the power management timer by exposing the verified read function and providing a helper function which checks the pmtmr_ioport variable and returns either the pm timer readout or 0 in case the pm timer is not available. Create a new header file and replace also the ifdef'ed extern definition in arch/i386/kernel/acpi/boot.c This is a preperatory patch for the rework of the local apic timer calibration. No functional changes. Signed-off-by:
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Thomas Gleixner authored
This is a preperatory patch for highres/dyntick: - replace the big #ifdef ARCH_APICTIMER_STOPS_ON_C3 hackery by functions - remove the double switch in the power verify function (in the worst case we switched ipi to apic and 20usec later apic to ipi) - keep track of the the state which stops local APIC timer Signed-off-by:
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Thomas Gleixner authored
apic.h does not get included on UP compiles. That way the APICTIMER_STOPS_ON_C3 is not there and UP boxen have no support for timer broadcasting. This was never noticed, because the lapic timer is only used for profiling on UP. Signed-off-by:
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Thomas Gleixner authored
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:
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Thomas Gleixner authored
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:
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Thomas Gleixner authored
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:
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Thomas Gleixner authored
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:
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Thomas Gleixner authored
- 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:
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Thomas Gleixner authored
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:
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Thomas Gleixner authored
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:
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Ingo Molnar authored
Uninline irq_enter(). [dynticks adds more stuff to it] No functional changes. Signed-off-by:
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Marcelo Tosatti authored
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:
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Thomas Gleixner authored
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:
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Thomas Gleixner authored
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:
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Thomas Gleixner authored
Fixup the is_contionous replacement by a flag field. Signed-off-by:
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Thomas Gleixner authored
Fixup the is_contionous replacement by a flag field. Signed-off-by:
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Thomas Gleixner authored
Fixup the is_contionous replacement by a flag field. Signed-off-by:
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Thomas Gleixner authored
Fixup the is_contionous replacement by a flag field. Signed-off-by:
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Thomas Gleixner authored
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:
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Ingo Molnar authored
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:
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Thomas Gleixner authored
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:
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Thomas Gleixner authored
The delayed work code in arch/i386/kernel/tsc.c is an unused leftover of the GTOD conversion. Remove it. Signed-off-by:
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John Stultz authored
Persistent clock support: do proper timekeeping across suspend/resume, i386 arch support. [bunk@stusta.de: cleanup] Build-fixes-from: Andrew Morton <akpm@osdl.org> Signed-off-by:
John Stultz <johnstul@us.ibm.com> Signed-off-by:
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John Stultz authored
Persistent clock support: do proper timekeeping across suspend/resume. [bunk@stusta.de: cleanup] Signed-off-by:
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Ingo Molnar authored
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:
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Ingo Molnar authored
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:
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Ingo Molnar authored
There are loads of fat functions hidden in jiffies.h. Uninline them. No code changes. [jeremy@goop.org: export fix] Signed-off-by:
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john stultz authored
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:
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Thomas Gleixner authored
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:
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Thomas Gleixner authored
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:
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Andrew Morton authored
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:
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Adrian Bunk authored
Advanced Mathematics, lesson 1: 101 != 105 ;-) Signed-off-by:
Adrian Bunk <bunk@stusta.de> Acked-by:
Tilman Schmidt <tilman@imap.cc> Signed-off-by:
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Jeff Dike authored
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:
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