aboutsummaryrefslogtreecommitdiffstats
path: root/arch/i386/kernel/tsc.c
Commit message (Collapse)AuthorAge
* i386: prepare shared kernel/tsc.cThomas Gleixner2007-10-11
| | | | | Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* sched: sched_clock_idle_[sleep|wakeup]_event()Ingo Molnar2007-08-23
| | | | | | | | | | | | | | | | | | | | construct a more or less wall-clock time out of sched_clock(), by using ACPI-idle's existing knowledge about how much time we spent idling. This allows the rq clock to work around TSC-stops-in-C2, TSC-gets-corrupted-in-C3 type of problems. ( Besides the scheduler's statistics this also benefits blktrace and printk-timestamps as well. ) Furthermore, the precise before-C2/C3-sleep and after-C2/C3-wakeup callbacks allow the scheduler to get out the most of the period where the CPU has a reliable TSC. This results in slightly more precise task statistics. the ACPI bits were acked by Len. Signed-off-by: Ingo Molnar <mingo@elte.hu> Acked-by: Len Brown <len.brown@intel.com>
* lguest: the host codeRusty Russell2007-07-19
| | | | | | | | | | | | | | | | This is the code for the "lg.ko" module, which allows lguest guests to be launched. [akpm@linux-foundation.org: update for futex-new-private-futexes] [akpm@linux-foundation.org: build fix] [jmorris@namei.org: lguest: use hrtimers] [akpm@linux-foundation.org: x86_64 build fix] Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Andi Kleen <ak@suse.de> Cc: Eric Dumazet <dada1@cosmosbay.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Add a sched_clock paravirt_opJeremy Fitzhardinge2007-07-18
| | | | | | | | | | | | | | | | | | | | | | | The tsc-based get_scheduled_cycles interface is not a good match for Xen's runstate accounting, which reports everything in nanoseconds. This patch replaces this interface with a sched_clock interface, which matches both Xen and VMI's requirements. In order to do this, we: 1. replace get_scheduled_cycles with sched_clock 2. hoist cycles_2_ns into a common header 3. update vmi accordingly One thing to note: because sched_clock is implemented as a weak function in kernel/sched.c, we must define a real function in order to override this weak binding. This means the usual paravirt_ops technique of using an inline function won't work in this case. Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Zachary Amsden <zach@vmware.com> Cc: Dan Hecht <dhecht@vmware.com> Cc: john stultz <johnstul@us.ibm.com>
* sched: x86, track TSC-unstable eventsIngo Molnar2007-07-09
| | | | | | | | track TSC-unstable events and propagate it to the scheduler code. Also allow sched_clock() to be used when the TSC is unstable, the rq_clock() wrapper creates a reliable clock out of it. Signed-off-by: Ingo Molnar <mingo@elte.hu>
* [PATCH] i386: remove xtime_lock'ing around cpufreq notifierDaniel Walker2007-05-02
| | | | | | | | | | | | | | | | | | The locking of the xtime_lock around the cpu notifier is unessesary now. At one time the tsc was used after a frequency change for timekeeping, but the re-write of timekeeping no longer uses the TSC unless the frequency is constant. The variables that are changed in this section of code had also once been used for timekeeping, but not any longer .. Signed-off-by: Daniel Walker <dwalker@mvista.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Andi Kleen <ak@suse.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: john stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* [PATCH] x86: Log reason why TSC was marked unstablejohn stultz2007-05-02
| | | | | | | | | | | | | | | | | Change mark_tsc_unstable() so it takes a string argument, which holds the reason the TSC was marked unstable. This is then displayed the first time mark_tsc_unstable is called. This should help us better debug why the TSC was marked unstable on certain systems and allow us to make sure we're not being overly paranoid when throwing out this troublesome clocksource. Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andi Kleen <ak@suse.de>
* [PATCH] i386: Prevent early access to TSC to avoid crash on TSCless systemsThomas Gleixner2007-03-24
| | | | | | | | | | | | | | | | commit f9690982b8c2f9a2c65acdc113e758ec356676a3 removed the check for cpu_khz from sched_clock(), which prevented early access to the TSC by non obvious magic. This is harmless as long as the CPU has a TSC. On TSCless systems this results in an illegal instruction trap. Replace tsc_disabled and tsc_unstable by tsc_enabled, which is only set when the tsc is available and not unstable. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] i386: Don't use the TSC in sched_clock if unstableGuillaume Chazarain2007-03-16
| | | | | | | | | http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=f9690982b8c2f9a2c65acdc113e758ec356676a3 caused a regression by letting sched_clock use the TSC even when cpufreq disabled it. This caused scheduling weirdnesses. Signed-off-by: Guillaume Chazarain <guichaz@yahoo.fr> Signed-off-by: Andi Kleen <ak@suse.de>
* [PATCH] remove arch/i386/kernel/tsc.c:custom_sched_clockAdrian Bunk2007-03-06
| | | | | | | | | | Remove the no longer used custom_sched_clock. Signed-off-by: Adrian Bunk <bunk@stusta.de> Acked-by: Zachary Amsden <zach@vmware.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>
* [PATCH] clocksource init adjustments (fix bug #7426)john stultz2007-03-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch resolves the issue found here: http://bugme.osdl.org/show_bug.cgi?id=7426 The basic summary is: Currently we register most of i386/x86_64 clocksources at module_init time. Then we enable clocksource selection at late_initcall time. This causes some problems for drivers that use gettimeofday for init calibration routines (specifically the es1968 driver in this case), where durring module_init, the only clocksource available is the low-res jiffies clocksource. This may cause slight calibration errors, due to the small sampling time used. It should be noted that drivers that require fine grained time may not function on architectures that do not have better then jiffies resolution timekeeping (there are a few). However, this does not discount the reasonable need for such fine-grained timekeeping at init time. Thus the solution here is to register clocksources earlier (ideally when the hardware is being initialized), and then we enable clocksource selection at fs_initcall (before device_initcall). This patch should probably get some testing time in -mm, since clocksource selection is one of the most important issues for correct timekeeping, and I've only been able to test this on a few of my own boxes. Signed-off-by: John Stultz <johnstul@us.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] vmi: cpu cycles fixZachary Amsden2007-03-05
| | | | | | | | | | | | In order to share the common code in tsc.c which does CPU Khz calibration, we need to make an accurate value of CPU speed available to the tsc.c code. This value loses a lot of precision in a VM because of the timing differences with real hardware, but we need it to be as precise as possible so the guest can make accurate time calculations with the cycle counters. Signed-off-by: Zachary Amsden <zach@vmware.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] vmi: sched clock paravirt op fixZachary Amsden2007-03-05
| | | | | | | | | | | | | | | | | | | | | | | | The custom_sched_clock hook is broken. The result from sched_clock needs to be in nanoseconds, not in CPU cycles. The TSC is insufficient for this purpose, because TSC is poorly defined in a virtual environment, and mostly represents real world time instead of scheduled process time (which can be interrupted without notice when a virtual machine is descheduled). To make the scheduler consistent, we must expose a different nature of time, that is scheduled time. So deprecate this custom_sched_clock hack and turn it into a paravirt-op, as it should have been all along. This allows the tsc.c code which converts cycles to nanoseconds to be shared by all paravirt-ops backends. It is unfortunate to add a new paravirt-op, but this is a very distinct abstraction which is clearly different for all virtual machine implementations, and it gets rid of an ugly indirect function which I ashamedly admit I hacked in to try to get this to work earlier, and then even got in the wrong units. Signed-off-by: Zachary Amsden <zach@vmware.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] Mark TSC on GeodeLX reliableMarcelo Tosatti2007-02-16
| | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* [PATCH] clocksource: Add verification (watchdog) helperThomas Gleixner2007-02-16
| | | | | | | | | | | | | | | 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>
* [PATCH] clocksource: Remove the update callbackThomas Gleixner2007-02-16
| | | | | | | | | | | | | 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>
* [PATCH] clocksource: replace is_continuous by a flag fieldThomas Gleixner2007-02-16
| | | | | | | | | | | | | 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>
* [PATCH] x86: rewrite SMP TSC sync codeIngo Molnar2007-02-16
| | | | | | | | | | | | | | | | | | | | | | 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>
* [PATCH] Simplify the registration of clocksourcesThomas Gleixner2007-02-16
| | | | | | | | | | | | | | 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>
* [PATCH] i386 Remove useless code in tsc.cThomas Gleixner2007-02-16
| | | | | | | | | | | | 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>
* [PATCH] i386: improve sched_clock() on i686Ingo Molnar2007-02-13
| | | | | | | | | | | | | | | | | | | | | Clean up sched_clock() on i686: it will use the TSC if available and falls back to jiffies only if the user asked for it to be disabled via notsc or the CPU calibration code didnt figure out the right cpu_khz. This generally makes the scheduler timestamps more finegrained, on all hardware. (the current scheduler is pretty resistant against asynchronous sched_clock() values on different CPUs, it will allow at most up to a jiffy of jitter.) Also simplify sched_clock()'s check for TSC availability: propagate the desire and ability to use the TSC into the tsc_disable flag, previously this flag only indicated whether the notsc option was passed. This makes the rare low-res sched_clock() codepath a single branch off a read-mostly flag. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Andi Kleen <ak@suse.de>
* [PATCH] i386: vMI timer patchesZachary Amsden2007-02-13
| | | | | | | | | | | | | | | | | | | | VMI timer code. It works by taking over the local APIC clock when APIC is configured, which requires a couple hooks into the APIC code. The backend timer code could be commonized into the timer infrastructure, but there are some pieces missing (stolen time, in particular), and the exact semantics of when to do accounting for NO_IDLE need to be shared between different hypervisors as well. So for now, VMI timer is a separate module. [Adrian Bunk: cleanups] Subject: VMI timer patches Signed-off-by: Zachary Amsden <zach@vmware.com> Signed-off-by: Andi Kleen <ak@suse.de> 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@osdl.org>
* [PATCH] i386: sched_clock using init data tsc_disable fixVivek Goyal2007-01-11
| | | | | | | | | | | | | | o sched_clock() a non-init function is using init data tsc_disable. This is flagged by MODPOST on i386 if CONFIG_RELOCATABLE=y WARNING: vmlinux - Section mismatch: reference to .init.data:tsc_disable from .text between 'sched_clock' (at offset 0xc0109d58) and 'tsc_update_callback' Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com> Cc: Andi Kleen <ak@suse.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Merge branch 'for-linus' of git://one.firstfloor.org/home/andi/git/linux-2.6Linus Torvalds2006-12-07
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'for-linus' of git://one.firstfloor.org/home/andi/git/linux-2.6: (156 commits) [PATCH] x86-64: Export smp_call_function_single [PATCH] i386: Clean up smp_tune_scheduling() [PATCH] unwinder: move .eh_frame to RODATA [PATCH] unwinder: fully support linker generated .eh_frame_hdr section [PATCH] x86-64: don't use set_irq_regs() [PATCH] x86-64: check vector in setup_ioapic_dest to verify if need setup_IO_APIC_irq [PATCH] x86-64: Make ix86 default to HIGHMEM4G instead of NOHIGHMEM [PATCH] i386: replace kmalloc+memset with kzalloc [PATCH] x86-64: remove remaining pc98 code [PATCH] x86-64: remove unused variable [PATCH] x86-64: Fix constraints in atomic_add_return() [PATCH] x86-64: fix asm constraints in i386 atomic_add_return [PATCH] x86-64: Correct documentation for bzImage protocol v2.05 [PATCH] x86-64: replace kmalloc+memset with kzalloc in MTRR code [PATCH] x86-64: Fix numaq build error [PATCH] x86-64: include/asm-x86_64/cpufeature.h isn't a userspace header [PATCH] unwinder: Add debugging output to the Dwarf2 unwinder [PATCH] x86-64: Clarify error message in GART code [PATCH] x86-64: Fix interrupt race in idle callback (3rd try) [PATCH] x86-64: Remove unwind stack pointer alignment forcing again ... Fixed conflict in include/linux/uaccess.h manually Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| * [PATCH] i386: Fix double #includes in arch/i386Nicolas Kaiser2006-12-06
| | | | | | | | | | | | | | Fix double #includes in arch/i386 Signed-off-by: Nicolas Kaiser <nikai@nikai.net> Signed-off-by: Andi Kleen <ak@suse.de>
* | WorkStruct: make allyesconfigDavid Howells2006-11-22
|/ | | | | | Fix up for make allyesconfig. Signed-Off-By: David Howells <dhowells@redhat.com>
* [PATCH] i386 Time: Avoid PIT SMP lockupsjohn stultz2006-10-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Avoid possible PIT livelock issues seen on SMP systems (and reported by Andi), by not allowing it as a clocksource on SMP boxes. However, since the PIT may no longer be present, we have to properly handle the cases where SMP systems have TSC skew and fall back from the TSC. Since the PIT isn't there, it would "fall back" to the TSC again. So this changes the jiffies rating to 1, and the TSC-bad rating value to 0. Thus you will get the following behavior priority on i386 systems: tsc [if present & stable] hpet [if present] cyclone [if present] acpi_pm [if present] pit [if UP] jiffies Rather then the current more complicated: tsc [if present & stable] hpet [if present] cyclone [if present] acpi_pm [if present] pit [if cpus < 4] tsc [if present & unstable] jiffies Signed-off-by: John Stultz <johnstul@us.ibm.com> Cc: Andi Kleen <ak@suse.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] i386: mark two more functions as __initMagnus Damm2006-09-26
| | | | | | | | | | | cyrix_identify() should be __init because transmeta_identify() is. tsc_init() is only called from setup_arch() which is marked as __init. These two section mismatches have been detected using running modpost on a vmlinux image compiled with CONFIG_RELOCATABLE=y. Signed-off-by: Magnus Damm <magnus@valinux.co.jp> Signed-off-by: Andi Kleen <ak@suse.de>
* [PATCH] generic-time: add macro to simplify/hide mask constantsJim Cromie2006-06-26
| | | | | | | | | | | Add a CLOCKSOURCE_MASK macro to simplify initializing the mask for a struct clocksource, and use it to replace literal mask constants in the various clocksource drivers. Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Acked-by: John Stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] time: rename clocksource functionsjohn stultz2006-06-26
| | | | | | | | | | | As suggested by Roman Zippel, change clocksource functions to use clocksource_xyz rather then xyz_clocksource to avoid polluting the namespace. Signed-off-by: John Stultz <johnstul@us.ibm.com> Cc: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Time: i386 Clocksource Driversjohn stultz2006-06-26
| | | | | | | | | | | | | | | | | Implement the time sources for i386 (acpi_pm, cyclone, hpet, pit, and tsc). With this patch, the conversion of the i386 arch to the generic timekeeping code should be complete. The patch should be fairly straight forward, only adding the new clocksources. [hirofumi@mail.parknet.co.jp: acpi_pm cleanup] Signed-off-by: John Stultz <johnstul@us.ibm.com> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Paul Mundt <lethal@linux-sh.org> Signed-off-by: John Stultz <johnstul@us.ibm.com> Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Time: i386 Conversion - part 3: Enable Generic Timekeepingjohn stultz2006-06-26
| | | | | | | | | | | | | | | This converts the i386 arch to use the generic timeofday subsystem. It enabled the GENERIC_TIME option, disables the timer_opts code and other arch specific timekeeping code and reworks the delay code. While this patch enables the generic timekeeping, please note that this patch does not provide any i386 clocksource. Thus only the jiffies clocksource will be available. To get full replacements for the code being disabled here, the timeofday-clocks-i386 patch will needed. Signed-off-by: John Stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Time: i386 Conversion - part 2: Rework TSC Supportjohn stultz2006-06-26
As part of the i386 conversion to the generic timekeeping infrastructure, this introduces a new tsc.c file. The code in this file replaces the TSC initialization, management and access code currently in timer_tsc.c (which will be removed) that we want to preserve. The code also introduces the following functionality: o tsc_khz: like cpu_khz but stores the TSC frequency on systems that do not change TSC frequency w/ CPU frequency o check/mark_tsc_unstable: accessor/modifier flag for TSC timekeeping usability o minor cleanups to calibration math. This patch also includes a one line __cpuinitdata fix from Zwane Mwaikambo. Signed-off-by: John Stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>