- 16 Feb, 2007 40 commits
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Paul E. McKenney authored
Use RCU to avoid the need to acquire tasklist_lock in the single-threaded case of clock_gettime(). It still acquires tasklist_lock when for a (potentially multithreaded) process. This change allows realtime applications to frequently monitor CPU consumption of individual tasks, as requested (and now deployed) by some off-list users. This has been in Ingo Molnar's -rt patchset since late 2005 with no problems reported, and tests successfully on 2.6.20-rc6, so I believe that it is long-since ready for mainline adoption. [paulmck@linux.vnet.ibm.com: fix exit()/posix_cpu_clock_get() race spotted by Oleg] Signed-off-by:
Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by:
Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: john stultz <johnstul@us.ibm.com> Cc: Roman Zippel <zippel@linux-m68k.org> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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john stultz authored
Cleanup and re-enable vsyscall gettimeofday using the generic clocksource infrastructure. [akpm@osdl.org: cleanup] Signed-off-by:
John Stultz <johnstul@us.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andi Kleen <ak@muc.de> Cc: Roman Zippel <zippel@linux-m68k.org> Signed-off-by:
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john stultz authored
This patch converts x86_64 to use the GENERIC_TIME infrastructure and adds clocksource structures for both TSC and HPET (ACPI PM is shared w/ i386). [akpm@osdl.org: fix printk timestamps] [akpm@osdl.org: fix printk ckeanups] [akpm@osdl.org: hpet build fix] Signed-off-by:
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john stultz authored
In preparation for the x86_64 generic time conversion, this patch splits out TSC and HPET related code from arch/x86_64/kernel/time.c into respective hpet.c and tsc.c files. [akpm@osdl.org: fix printk timestamps] [akpm@osdl.org: cleanup] Signed-off-by:
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john stultz authored
In preparation for supporting generic timekeeping, this patch cleans up x86-64's use of vxtime.hpet_address, changing it to just hpet_address as is also used in i386. This is necessary since the vxtime structure will be going away. Signed-off-by:
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john stultz authored
Provides generic infrastructure for vsyscall-gtod. [akpm@osdl.org: cleanup] Signed-off-by:
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Ingo Molnar authored
Add SysRq-Q to print pending timers and other timer info. 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:
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Ingo Molnar authored
add /proc/timer_list, which prints all currently pending (high-res) timers, all clock-event sources and their parameters in a human-readable form. Sample output: Timer List Version: v0.1 HRTIMER_MAX_CLOCK_BASES: 2 now at 4246046273872 nsecs cpu: 0 clock 0: .index: 0 .resolution: 1 nsecs .get_time: ktime_get_real .offset: 1273998312645738432 nsecs active timers: clock 1: .index: 1 .resolution: 1 nsecs .get_time: ktime_get .offset: 0 nsecs active timers: #0: <f5a90ec8>, hrtimer_sched_tick, hrtimer_stop_sched_tick, swapper/0 # expires at 4246432689566 nsecs [in 386415694 nsecs] #1: <f5a90ec8>, hrtimer_wakeup, do_nanosleep, pcscd/2050 # expires at 4247018194689 nsecs [in 971920817 nsecs] #2: <f5a90ec8>, hrtimer_wakeup, do_nanosleep, irqbalance/1909 # expires at 4247351358392 nsecs [in 1305084520 nsecs] #3: <f5a90ec8>, hrtimer_wakeup, do_nanosleep, crond/2157 # expires at 4249097614968 nsecs [in 3051341096 nsecs] #4: <f5a90ec8>, it_real_fn, do_setitimer, syslogd/1888 # expires at 4251329900926 nsecs [in 5283627054 nsecs] .expires_next : 4246432689566 nsecs .hres_active : 1 .check_clocks : 0 .nr_events : 31306 .idle_tick : 4246020791890 nsecs .tick_stopped : 1 .idle_jiffies : 986504 .idle_calls : 40700 .idle_sleeps : 36014 .idle_entrytime : 4246019418883 nsecs .idle_sleeptime : 4178181972709 nsecs cpu: 1 clock 0: .index: 0 .resolution: 1 nsecs .get_time: ktime_get_real .offset: 1273998312645738432 nsecs active timers: clock 1: .index: 1 .resolution: 1 nsecs .get_time: ktime_get .offset: 0 nsecs active timers: #0: <f5a90ec8>, hrtimer_sched_tick, hrtimer_restart_sched_tick, swapper/0 # expires at 4246050084568 nsecs [in 3810696 nsecs] #1: <f5a90ec8>, hrtimer_wakeup, do_nanosleep, atd/2227 # expires at 4261010635003 nsecs [in 14964361131 nsecs] #2: <f5a90ec8>, hrtimer_wakeup, do_nanosleep, smartd/2332 # expires at 5469485798970 nsecs [in 1223439525098 nsecs] .expires_next : 4246050084568 nsecs .hres_active : 1 .check_clocks : 0 .nr_events : 24043 .idle_tick : 4246046084568 nsecs .tick_stopped : 0 .idle_jiffies : 986510 .idle_calls : 26360 .idle_sleeps : 22551 .idle_entrytime : 4246043874339 nsecs .idle_sleeptime : 4170763761184 nsecs tick_broadcast_mask: 00000003 event_broadcast_mask: 00000001 CPU#0's local event device: Clock Event Device: lapic capabilities: 0000000e max_delta_ns: 807385544 min_delta_ns: 1443 mult: 44624025 shift: 32 set_next_event: lapic_next_event set_mode: lapic_timer_setup event_handler: hrtimer_interrupt .installed: 1 .expires: 4246432689566 nsecs CPU#1's local event device: Clock Event Device: lapic capabilities: 0000000e max_delta_ns: 807385544 min_delta_ns: 1443 mult: 44624025 shift: 32 set_next_event: lapic_next_event set_mode: lapic_timer_setup event_handler: hrtimer_interrupt .installed: 1 .expires: 4246050084568 nsecs Clock Event Device: hpet capabilities: 00000007 max_delta_ns: 2147483647 min_delta_ns: 3352 mult: 61496110 shift: 32 set_next_event: hpet_next_event set_mode: hpet_set_mode event_handler: handle_nextevt_broadcast Signed-off-by:
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Ingo Molnar authored
Add /proc/timer_stats support: debugging feature to profile timer expiration. Both the starting site, process/PID and the expiration function is captured. This allows the quick identification of timer event sources in a system. Sample output: # echo 1 > /proc/timer_stats # cat /proc/timer_stats Timer Stats Version: v0.1 Sample period: 4.010 s 24, 0 swapper hrtimer_stop_sched_tick (hrtimer_sched_tick) 11, 0 swapper sk_reset_timer (tcp_delack_timer) 6, 0 swapper hrtimer_stop_sched_tick (hrtimer_sched_tick) 2, 1 swapper queue_delayed_work_on (delayed_work_timer_fn) 17, 0 swapper hrtimer_restart_sched_tick (hrtimer_sched_tick) 2, 1 swapper queue_delayed_work_on (delayed_work_timer_fn) 4, 2050 pcscd do_nanosleep (hrtimer_wakeup) 5, 4179 sshd sk_reset_timer (tcp_write_timer) 4, 2248 yum-updatesd schedule_timeout (process_timeout) 18, 0 swapper hrtimer_restart_sched_tick (hrtimer_sched_tick) 3, 0 swapper sk_reset_timer (tcp_delack_timer) 1, 1 swapper neigh_table_init_no_netlink (neigh_periodic_timer) 2, 1 swapper e1000_up (e1000_watchdog) 1, 1 init schedule_timeout (process_timeout) 100 total events, 25.24 events/sec [ cleanups and hrtimers support from Thomas Gleixner <tglx@linutronix.de> ] [bunk@stusta.de: nr_entries can become static] Signed-off-by:
Adrian Bunk <bunk@stusta.de> Signed-off-by:
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Thomas Gleixner authored
Fix potential setitimer DoS with high-res timers by pushing itimer rearm processing to process context. [Fixes from: Ingo Molnar <mingo@elte.hu>] Signed-off-by:
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Thomas Gleixner authored
Implement high resolution timers on top of the hrtimers infrastructure and the clockevents / tick-management framework. This provides accurate timers for all hrtimer subsystem users. Signed-off-by:
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Ingo Molnar authored
Enable dynamic ticks selection. Signed-off-by:
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Thomas Gleixner authored
The NMI watchdog implementation assumes that the local APIC timer interrupt is happening. This assumption is not longer true when high resolution timers and dynamic ticks come into play, as they may switch off the local APIC timer completely. Take the PIT/HPET interrupts into account too, to avoid false positives. Signed-off-by:
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Ingo Molnar authored
Prepare i386 for dyntick: idle handler callbacks. Signed-off-by:
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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:
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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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