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2007-05-29NOHZ: prevent multiplication overflow - stop timer for huge timeoutsThomas Gleixner
get_next_timer_interrupt() returns a delta of (LONG_MAX > 1) in case there is no timer pending. On 64 bit machines this results in a multiplication overflow in tick_nohz_stop_sched_tick(). Reported by: Dave Miller <davem@davemloft.net> Make the return value a constant and limit the return value to a 32 bit value. When the max timeout value is returned, we can safely stop the tick timer device. The max jiffies delta results in a 12 days timeout for HZ=1000. In the long term the get_next_timer_interrupt() code needs to be reworked to return ktime instead of jiffies, but we have to wait until the last users of the original NO_IDLE_HZ code are converted. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-23NOHZ: Rate limit the local softirq pending warning outputThomas Gleixner
The warning in the NOHZ code, which triggers when a CPU goes idle with softirqs pending can fill up the logs quite quickly. Rate limit the output until we found the root cause of that problem. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-23Ignore bogus ACPI info for offline CPUsThomas Gleixner
Booting a SMP kernel with maxcpus=1 on a SMP system leads to a hard hang, because ACPI ignores the maxcpus setting and sends timer broadcast info for the offline CPUs. This results in a stuck for ever call to smp_call_function_single() on an offline CPU. Ignore the bogus information and print a kernel error to remind ACPI folks to fix it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-21Detach sched.h from mm.hAlexey Dobriyan
First thing mm.h does is including sched.h solely for can_do_mlock() inline function which has "current" dereference inside. By dealing with can_do_mlock() mm.h can be detached from sched.h which is good. See below, why. This patch a) removes unconditional inclusion of sched.h from mm.h b) makes can_do_mlock() normal function in mm/mlock.c c) exports can_do_mlock() to not break compilation d) adds sched.h inclusions back to files that were getting it indirectly. e) adds less bloated headers to some files (asm/signal.h, jiffies.h) that were getting them indirectly Net result is: a) mm.h users would get less code to open, read, preprocess, parse, ... if they don't need sched.h b) sched.h stops being dependency for significant number of files: on x86_64 allmodconfig touching sched.h results in recompile of 4083 files, after patch it's only 3744 (-8.3%). Cross-compile tested on all arm defconfigs, all mips defconfigs, all powerpc defconfigs, alpha alpha-up arm i386 i386-up i386-defconfig i386-allnoconfig ia64 ia64-up m68k mips parisc parisc-up powerpc powerpc-up s390 s390-up sparc sparc-up sparc64 sparc64-up um-x86_64 x86_64 x86_64-up x86_64-defconfig x86_64-allnoconfig as well as my two usual configs. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-15clocksource: fix lock order in the resume pathThomas Gleixner
lockdep complains about the lock nesting of clocksource and watchdog lock in the resume path. Change the resume marker to a bit operation and remove the lock from this path. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: john stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-14timekeeping fix patch got mis-appliedThomas Gleixner
The time keeping code move to kernel/time/timekeeping.c broke the clocksource resume logic patch, which got applied to the old file by a fuzzy application. Fix it up and move the clocksource_resume() call to the appropriate place. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> [ tssk, tssk, everybody should use --fuzz=0 ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09clocksource: fix resume logicThomas Gleixner
We need to make sure that the clocksources are resumed, when timekeeping is resumed. The current resume logic does not guarantee this. Add a resume function pointer to the clocksource struct, so clocksource drivers which need to reinitialize the clocksource can provide a resume function. Add a resume function, which calls the maybe available clocksource resume functions and resets the watchdog function, so a stable TSC can be used accross suspend/resume. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: john stultz <johnstul@us.ibm.com> Cc: Andi Kleen <ak@suse.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09Fix printk format warnings in timer_list.cDavid Miller
u64 and s64 are not necessarily 'long long' on some 64-bit platforms, so explicit the type to kill the compiler warnings. Also consistently use '%Lu' which is unsigned. Signed-off-by: David S. Miller <davem@davemloft.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09clocksource: spelling error in watchdog codeDaniel Walker
There's more that need fixing, and fix my own subject spelling error too. Signed-off-by: Daniel Walker <dwalker@mvista.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08sched: dynticks idle load balancingSiddha, Suresh B
Fix the process idle load balancing in the presence of dynticks. cpus for which ticks are stopped will sleep till the next event wakes it up. Potentially these sleeps can be for large durations and during which today, there is no periodic idle load balancing being done. This patch nominates an owner among the idle cpus, which does the idle load balancing on behalf of the other idle cpus. And once all the cpus are completely idle, then we can stop this idle load balancing too. Checks added in fast path are minimized. Whenever there are busy cpus in the system, there will be an owner(idle cpu) doing the system wide idle load balancing. Open items: 1. Intelligent owner selection (like an idle core in a busy package). 2. Merge with rcu's nohz_cpu_mask? Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08highres/dyntick: prevent xtime lock contentionThomas Gleixner
While the !highres/!dyntick code assigns the duty of the do_timer() call to one specific CPU, this was dropped in the highres/dyntick part during development. Steven Rostedt discovered the xtime lock contention on highres/dyntick due to several CPUs trying to update jiffies. Add the single CPU assignement back. In the dyntick case this needs to be handled carefully, as the CPU which has the do_timer() duty must drop the assignement and let it be grabbed by another CPU, which is active. Otherwise the do_timer() calls would not happen during the long sleep. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Steven Rostedt <rostedt@goodmis.org> Acked-by: Mark Lord <mlord@pobox.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08Fix race between cat /proc/*/wchan and rmmod et alAlexey Dobriyan
kallsyms_lookup() can go iterating over modules list unprotected which is OK for emergency situations (oops), but not OK for regular stuff like /proc/*/wchan. Introduce lookup_symbol_name()/lookup_module_symbol_name() which copy symbol name into caller-supplied buffer or return -ERANGE. All copying is done with module_mutex held, so... Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08Simplify kallsyms_lookup()Alexey Dobriyan
Several kallsyms_lookup() pass dummy arguments but only need, say, module's name. Make kallsyms_lookup() accept NULLs where possible. Also, makes picture clearer about what interfaces are needed for all symbol resolving business. Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Cc: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08Move timekeeping code to timekeeping.cjohn stultz
Move the timekeeping code out of kernel/timer.c and into kernel/time/timekeeping.c. I made no cleanups or other changes in transit. [akpm@linux-foundation.org: build fix] Signed-off-by: John Stultz <johnstul@us.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-04-04[PATCH] fix jiffies clocksource inittimejohn stultz
In debugging a problem w/ the -rt tree, I noticed that on systems that mark the tsc as unstable before it is registered, the TSC would still be selected and used for a short period of time. Digging in it looks to be a result of the mix of the clocksource list changes and my clocksource initialization changes. With the -rt tree, using a bad TSC, even for a short period of time can results in a hang at boot. I was not able to reproduce this hang w/ mainline, but I'm not completely certain that someone won't trip on it. This patch resolves the issue by initializing the jiffies clocksource earlier so a bad TSC won't get selected just because nothing else is yet registered. Signed-off-by: John Stultz <johnstul@us.ibm.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-27[PATCH] ntp: avoid time_offset overflowsjohn stultz
I've been seeing some odd NTP behavior recently on a few boxes and finally narrowed it down to time_offset overflowing when converted to SHIFT_UPDATE units (which was a side effect from my HZfreeNTP patch). This patch converts time_offset from a long to a s64 which resolves the issue. [tglx@linutronix.de: signedness fixes] Signed-off-by: John Stultz <johnstul@us.ibm.com> Cc: Roman Zippel <zippel@linux-m68k.org> Cc: john stultz <johnstul@us.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-26[PATCH] clockevents: remove bad designed sysfs support for nowThomas Gleixner
The current sysfs support of clockevents does not obey the "only one value per file" rule. The real fix is not 2.6.21 material. Therefor remove the sysfs support for now. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-25[PATCH] clocksource: Fix thinko in watchdog selectionThomas Gleixner
The watchdog implementation excludes low res / non continuous clocksources from being selected as a watchdog reference unintentionally. Allow using jiffies/PIT as a watchdog reference as long as no better clocksource is available. This is necessary to detect TSC breakage on systems, which have no pmtimer/hpet. The main goal of the initial patch (preventing to switch to highres/nohz when no reliable fallback clocksource is available) is still guaranteed by the checks in clocksource_watchdog(). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-23[PATCH] time: fix formatting in /proc/timer_listJames Morris
Fix the print formatting of three unsigned long fields in /proc/timer_list, which are currently being formatted as signed long. Signed-off-by: James Morris <jmorris@namei.org> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-16[PATCH] clockevents: Fix suspend/resume to disk hangsThomas Gleixner
I finally found a dual core box, which survives suspend/resume without crashing in the middle of nowhere. Sigh, I never figured out from the code and the bug reports what's going on. The observed hangs are caused by a stale state transition of the clock event devices, which keeps the RCU synchronization away from completion, when the non boot CPU is brought back up. The suspend/resume in oneshot mode needs the similar care as the periodic mode during suspend to RAM. My assumption that the state transitions during the different shutdown/bringups of s2disk would go through the periodic boot phase and then switch over to highres resp. nohz mode were simply wrong. Add the appropriate suspend / resume handling for the non periodic modes. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-06[PATCH] Save/restore periodic tick information over suspend/resumeThomas Gleixner
The programming of periodic tick devices needs to be saved/restored across suspend/resume - otherwise we might end up with a system coming up that relies on getting a PIT (or HPET) interrupt, while those devices default to 'no interrupts' after powerup. (To confuse things it worked to a certain degree on some systems because the lapic gets initialized as a side-effect of SMP bootup.) This suspend / resume thing was dropped unintentionally during the last-minute -mm code reshuffling. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-03-05[PATCH] clocksource init adjustments (fix bug #7426)john stultz
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>
2007-02-26[TICK] tick-common: Fix one-shot handling in tick_handle_periodic().David S. Miller
When clockevents_program_event() is given an expire time in the past, it does not update dev->next_event, so this looping code would loop forever once the first in-the-past expiration time was used. Keep advancing "next" locally to fix this bug. Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-02-26[TIME] tick-sched: Add missing asm/irq_regs.h include.David S. Miller
Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-02-19[PATCH] NOHZ: Produce debug output instead of a BUG()Thomas Gleixner
The BUG_ON() in tick_nohz_stop_sched_tick() triggers on some boxen. Remove the BUG_ON and print information about the pending softirq to allow better debugging of the problem. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-19[PATCH] NOHZ: Fix RCU handlingIngo Molnar
When a CPU is needed for RCU the tick has to continue even when it was stopped before. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-16[PATCH] Add debugging feature /proc/timer_listIngo Molnar
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: 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>
2007-02-16[PATCH] Add debugging feature /proc/timer_statIngo Molnar
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: 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: Andi Kleen <ak@suse.de> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-16[PATCH] hrtimers: add high resolution timer supportThomas Gleixner
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: 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>
2007-02-16[PATCH] tick-management: dyntick / highres functionalityThomas Gleixner
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: 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>
2007-02-16[PATCH] tick-management: broadcast functionalityThomas Gleixner
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: 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>
2007-02-16[PATCH] tick-management: core functionalityThomas Gleixner
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: 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>
2007-02-16[PATCH] clockevents: add core functionalityThomas Gleixner
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: 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>
2007-02-16[PATCH] clocksource: Add verification (watchdog) helperThomas Gleixner
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>
2007-02-16[PATCH] clocksource: replace is_continuous by a flag fieldThomas Gleixner
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>
2007-02-16[PATCH] Simplify the registration of clocksourcesThomas Gleixner
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>
2007-02-16[PATCH] HZ free ntpjohn stultz
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>
2007-02-11[PATCH] kernel/time/clocksource.c needs struct task_struct on m68kMathieu Desnoyers
kernel/time/clocksource.c needs struct task_struct on m68k. Because it uses spin_unlock_irq(), which, on m68k, uses hardirq_count(), which uses preempt_count(), which needs to dereference struct task_struct, we have to include sched.h. Because it would cause a loop inclusion, we cannot include sched.h in any other of asm-m68k/system.h, linux/thread_info.h, linux/hardirq.h, which leaves this ugly include in a C file as the only simple solution. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roman Zippel <zippel@linux-m68k.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2006-12-10[PATCH] clocksource: small cleanupDaniel Walker
Mostly changing alignment. Just some general cleanup. [akpm@osdl.org: build fix] Signed-off-by: Daniel Walker <dwalker@mvista.com> Acked-by: John Stultz <johnstul@us.ibm.com> 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>
2006-12-10[PATCH] clocksource: add usage of CONFIG_SYSFSDaniel Walker
Simply adds some ifdefs to remove clocksoure sysfs code when CONFIG_SYSFS isn't turn on. Signed-off-by: Daniel Walker <dwalker@mvista.com> Acked-by: John Stultz <johnstul@us.ibm.com> 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>
2006-10-28[PATCH] time_adjust cleared before useJim Houston
I notice that the code which implements adjtime clears the time_adjust value before using it. The attached patch makes the obvious fix. Acked-by: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: Jim Houston <jim.houston@ccur.com> Cc: John Stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-17[PATCH] i386 Time: Avoid PIT SMP lockupsjohn stultz
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>
2006-10-01[PATCH] kernel/time/ntp.c: possible cleanupsAdrian Bunk
This patch contains the following possible cleanups: - make the following needlessly global function static: - ntp_update_frequency() - make the following needlessly global variables static: - time_state - time_offset - time_constant - time_reftime - remove the following read-only global variable: - time_precision Signed-off-by: Adrian Bunk <bunk@stusta.de> Cc: Roman Zippel <zippel@linux-m68k.org> Cc: john stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01[PATCH] ntp: convert to the NTP4 reference modelRoman Zippel
This converts the kernel ntp model into a model which matches the nanokernel reference implementations. The previous patches already increased the resolution and precision of the computations, so that this conversion becomes quite simple. <linux@horizon.com> explains: The original NTP kernel interface was defined in units of microseconds. That's what Linux implements. As computers have gotten faster and can now split microseconds easily, a new kernel interface using nanosecond units was defined ("the nanokernel", confusing as that name is to OS hackers), and there's an STA_NANO bit in the adjtimex() status field to tell the application which units it's using. The current ntpd supports both, but Linux loses some possible timing resolution because of quantization effects, and the ntpd hackers would really like to be able to drop the backwards compatibility code. Ulrich Windl has been maintaining a patch set to do the conversion for years, but it's hard to keep in sync. Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Cc: john stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01[PATCH] ntp: convert time_freq to nsec valueRoman Zippel
This converts time_freq to a scaled nsec value and adds around 6bit of extra resolution. This pushes the time_freq to its 32bit limits so the calculatons have to be done with 64bit. Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Cc: john stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01[PATCH] ntp: remove time_toleranceRoman Zippel
time_tolerance isn't changed at all in the kernel, so simply remove it, this simplifies the next patch, as it avoids a number of conversions. Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Cc: john stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01[PATCH] ntp: add time_adjust to tick lengthRoman Zippel
This folds update_ntp_one_tick() into second_overflow() and adds time_adjust to the tick length, this makes time_next_adjust unnecessary. This slightly changes the adjtime() behaviour, instead of applying it to the next tick, it's applied to the next second. Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Cc: john stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01[PATCH] ntp: prescale time_offsetRoman Zippel
This converts time_offset into a scaled per tick value. This avoids now completely the crude compensation in second_overflow(). Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Cc: john stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01[PATCH] ntp: add time_freq to tick lengthRoman Zippel
This adds the frequency part to ntp_update_frequency(). Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Cc: john stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01[PATCH] ntp: add time_adj to tick lengthRoman Zippel
This makes time_adj local to second_overflow() and integrates it into the tick length instead of adding it everytime. Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Cc: john stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>