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* Cache xtime every call to update_wall_timejohn stultz2007-07-25
| | | | | | | | | | | | | | | | | | | | This avoids xtime lag seen with dynticks, because while 'xtime' itself is still not updated often, we keep a 'xtime_cache' variable around that contains the approximate real-time that _is_ updated each time we do a 'update_wall_time()', and is thus never off by more than one tick. IOW, this restores the original semantics for 'xtime' users, as long as you use the proper abstraction functions (ie 'current_kernel_time()' or 'get_seconds()' depending on whether you want a timespec or just the seconds field). [ Updated Patch. As penance for my sins I've also yanked another #ifdef that was added to avoid the xtime lag w/ hrtimers. ] Signed-off-by: John Stultz <johnstul@us.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Cleanup non-arch xtime uses, use get_seconds() or current_kernel_time().john stultz2007-07-25
| | | | | | | | | | | | | | | | | | This avoids use of the kernel-internal "xtime" variable directly outside of the actual time-related functions. Instead, use the helper functions that we already have available to us. This doesn't actually change any behaviour, but this will allow us to fix the fact that "xtime" isn't updated very often with CONFIG_NO_HZ (because much of the realtime information is maintained as separate offsets to 'xtime'), which has caused interfaces that use xtime directly to get a time that is out of sync with the real-time clock by up to a third of a second or so. Signed-off-by: John Stultz <johnstul@us.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* NTP: move the cmos update code into ntp.cThomas Gleixner2007-07-21
| | | | | | | | | | | | | | | | i386 and sparc64 have the identical code to update the cmos clock. Move it into kernel/time/ntp.c as there are other architectures coming along with the same requirements. [akpm@linux-foundation.org: build fixes] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Chris Wright <chrisw@sous-sol.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: john stultz <johnstul@us.ibm.com> Cc: David Miller <davem@davemloft.net> 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>
* highres: improve debug outputIngo Molnar2007-07-21
| | | | | | | | | | Add some more debug information to the hrtimer and clock events code. Signed-off-by: Ingo Molnar <mingo@elte.hu> 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>
* tick management: spread timer interruptjohn stultz2007-07-21
| | | | | | | | | | | | | | After discussing w/ Thomas over IRC, it seems the issue is the sched tick fires on every cpu at the same time, causing extra lock contention. This smaller change, adds an extra offset per cpu so the ticks don't line up. This patch also drops the idle latency from 40us down to under 20us. Signed-off-by: john stultz <johnstul@us.ibm.com> Signed-off-by: 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>
* clockevents: fix device replacementThomas Gleixner2007-07-21
| | | | | | | | | | | When a device is replaced by a better rated device, then the broadcast mode needs to be evaluated again. When the new device has no requirement for broadcasting, then the broadcast bits for the CPU must be cleared. 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>
* clockevents: fix resume logicThomas Gleixner2007-07-21
| | | | | | | | | | | | | | | | | | | | We need to make sure, that the clockevent devices are resumed, before the tick is resumed. The current resume logic does not guarantee this. Add CLOCK_EVT_MODE_RESUME and call the set mode functions of the clock event devices before resuming the tick / oneshot functionality. Fixup the existing users. Thanks to Nigel Cunningham for tracking down a long standing thinko, which affected the jinxed VAIO. [akpm@linux-foundation.org: xen build fix] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: john stultz <johnstul@us.ibm.com> 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>
* Pull ia64-clocksource into release branchTony Luck2007-07-20
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| * [IA64] remove time interpolatorBob Picco2007-07-20
| | | | | | | | | | | | | | | | | | | | | | Remove time_interpolator code (This is generic code, but only user was ia64. It has been superseded by the CONFIG_GENERIC_TIME code). Signed-off-by: Bob Picco <bob.picco@hp.com> Signed-off-by: John Stultz <johnstul@us.ibm.com> Signed-off-by: Peter Keilty <peter.keilty@hp.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
* | timekeeping: fixup shadow variable argumentThomas Gleixner2007-07-19
|/ | | | | | | | | | clocksource_adjust() has a clock argument, which shadows the file global clock variable. Fix this up. 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>
* kallsyms: make KSYM_NAME_LEN include space for trailing '\0'Tejun Heo2007-07-17
| | | | | | | | | | | | | | | | | | | | | | | | KSYM_NAME_LEN is peculiar in that it does not include the space for the trailing '\0', forcing all users to use KSYM_NAME_LEN + 1 when allocating buffer. This is nonsense and error-prone. Moreover, when the caller forgets that it's very likely to subtly bite back by corrupting the stack because the last position of the buffer is always cleared to zero. This patch increments KSYM_NAME_LEN by one and updates code accordingly. * off-by-one bug in asm-powerpc/kprobes.h::kprobe_lookup_name() macro is fixed. * Where MODULE_NAME_LEN and KSYM_NAME_LEN were used together, MODULE_NAME_LEN was treated as if it didn't include space for the trailing '\0'. Fix it. Signed-off-by: Tejun Heo <htejun@gmail.com> Acked-by: Paulo Marques <pmarques@grupopie.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Remove capability.h from mm.hAlexey Dobriyan2007-07-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I forgot to remove capability.h from mm.h while removing sched.h! This patch remedies that, because the only inline function which was using CAP_something was made out of line. Cross-compile tested without regressions on: all powerpc defconfigs all mips defconfigs all m68k defconfigs all arm defconfigs all ia64 defconfigs alpha alpha-allnoconfig alpha-defconfig alpha-up arm i386 i386-allnoconfig i386-defconfig i386-up ia64 ia64-allnoconfig ia64-defconfig ia64-up m68k mips parisc parisc-allnoconfig parisc-defconfig parisc-up powerpc powerpc-up s390 s390-allnoconfig s390-defconfig s390-up sparc sparc-allnoconfig sparc-defconfig sparc-up sparc64 sparc64-allnoconfig sparc64-defconfig sparc64-up um-x86_64 x86_64 x86_64-allnoconfig x86_64-defconfig x86_64-up as well as my two usual configs. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Add a flag to indicate deferrable timers in /proc/timer_statsVenki Pallipadi2007-07-16
| | | | | | | | | | | | | | | | | | | Add a flag in /proc/timer_stats to indicate deferrable timers. This will let developers/users to differentiate between types of tiemrs in /proc/timer_stats. Deferrable timer and normal timer will appear in /proc/timer_stats as below. 10D, 1 swapper queue_delayed_work_on (delayed_work_timer_fn) 10, 1 swapper queue_delayed_work_on (delayed_work_timer_fn) Also version of timer_stats changes from v0.1 to v0.2 Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Acked-by: 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> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Remove clockevents_{release,request}_deviceAndi Kleen2007-07-16
| | | | | | | | | | | Not called by anything in tree. Signed-off-by: Andi Kleen <ak@suse.de> Acked-by: 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> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Introduce boot based timeTomas Janousek2007-07-16
| | | | | | | | | | | | | | | | | | | | | | | | | The commits 411187fb05cd11676b0979d9fbf3291db69dbce2 (GTOD: persistent clock support) c1d370e167d66b10bca3b602d3740405469383de (i386: use GTOD persistent clock support) changed the monotonic time so that it no longer jumps after resume, but it's not possible to use it for boot time and process start time calculations then. Also, the uptime no longer increases during suspend. I add a variable to track the wall_to_monotonic changes, a function to get the real boot time and a function to get the boot based time from the monotonic one. [akpm@linux-foundation.org: remove exports, add comment] Signed-off-by: Tomas Janousek <tjanouse@redhat.com> Cc: Tomas Smetana <tsmetana@redhat.com> Cc: John Stultz <johnstul@us.ibm.com> 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>
* NTP: remove clock_was_set() call to prevent deadlockThomas Gleixner2007-07-03
| | | | | | | | | | | | | | | | | | | | | | | The clock_was_set() call in seconds_overflow() which happens only when leap seconds are inserted / deleted is wrong in two aspects: 1. it results in a call to on_each_cpu() with interrupts disabled 2. it is potential deadlock source vs. call_lock in smp_call_function() The only possible side effect of the removal might be, that an absolute CLOCK_REALTIME timer fires 1 second too late, in the rare case of leap second deletion and an absolute CLOCK_REALTIME timer which expires in the affected time frame. It will never fire too early. This was probably observed by the reporter of a June 30th -> July 1st hang: http://lkml.org/lkml/2007/7/3/103 A similar problem was observed by Dave Jones, who provided a screen shot with a lockdep back trace, which allowed to analyse the problem. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* timer stats: speedupsIngo Molnar2007-06-01
| | | | | | | | | | | | | | Make timer-stats have almost zero overhead when enabled in the config but not used. (this way distros can enable it more easily) Also update the documentation about overhead of timer_stats - it was written for the first version which had a global lock and a linear list walk based lookup ;-) Signed-off-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>
* timer statistics: fix raceBjorn Steinbrink2007-06-01
| | | | | | | | | | | | | | | | | Fix two races in the timer stats lookup code. One by ensuring that the initialization of a new entry is finished upon insertion of that entry. The other by cleaning up the hash table when the entries array is cleared, so that we don't have any "pre-inserted" entries. Thanks to Eric Dumazet for reminding me of the memory barriers. Signed-off-by: Bjorn Steinbrink <B.Steinbrink@gmx.de> Signed-off-by: Ian Kumlien <pomac@vapor.com> Acked-by: Ingo Molnar <mingo@elte.hu> 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>
* NOHZ: prevent multiplication overflow - stop timer for huge timeoutsThomas Gleixner2007-05-29
| | | | | | | | | | | | | | | | | | | | | | | 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>
* NOHZ: Rate limit the local softirq pending warning outputThomas Gleixner2007-05-23
| | | | | | | | | | | 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>
* Ignore bogus ACPI info for offline CPUsThomas Gleixner2007-05-23
| | | | | | | | | | | | | | | 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>
* Detach sched.h from mm.hAlexey Dobriyan2007-05-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* clocksource: fix lock order in the resume pathThomas Gleixner2007-05-15
| | | | | | | | | | | | | 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>
* timekeeping fix patch got mis-appliedThomas Gleixner2007-05-14
| | | | | | | | | | | 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>
* clocksource: fix resume logicThomas Gleixner2007-05-09
| | | | | | | | | | | | | | | | | | | | | 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>
* Fix printk format warnings in timer_list.cDavid Miller2007-05-09
| | | | | | | | | | | | | 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>
* clocksource: spelling error in watchdog codeDaniel Walker2007-05-09
| | | | | | | | 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>
* sched: dynticks idle load balancingSiddha, Suresh B2007-05-08
| | | | | | | | | | | | | | | | | | | | | | | | 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>
* highres/dyntick: prevent xtime lock contentionThomas Gleixner2007-05-08
| | | | | | | | | | | | | | | | | | | | | | 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>
* Fix race between cat /proc/*/wchan and rmmod et alAlexey Dobriyan2007-05-08
| | | | | | | | | | | | | | | 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>
* Simplify kallsyms_lookup()Alexey Dobriyan2007-05-08
| | | | | | | | | | | | | | 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>
* Move timekeeping code to timekeeping.cjohn stultz2007-05-08
| | | | | | | | | | | | 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>
* [PATCH] fix jiffies clocksource inittimejohn stultz2007-04-05
| | | | | | | | | | | | | | | | | | | | | | | 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>
* [PATCH] ntp: avoid time_offset overflowsjohn stultz2007-03-27
| | | | | | | | | | | | | | | | | | 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>
* [PATCH] clockevents: remove bad designed sysfs support for nowThomas Gleixner2007-03-26
| | | | | | | | | | | | | 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>
* [PATCH] clocksource: Fix thinko in watchdog selectionThomas Gleixner2007-03-25
| | | | | | | | | | | | | | | | | 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>
* [PATCH] time: fix formatting in /proc/timer_listJames Morris2007-03-23
| | | | | | | | | | | 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>
* [PATCH] clockevents: Fix suspend/resume to disk hangsThomas Gleixner2007-03-16
| | | | | | | | | | | | | | | | | | | | | | 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>
* [PATCH] Save/restore periodic tick information over suspend/resumeThomas Gleixner2007-03-06
| | | | | | | | | | | | | | | | 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>
* [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>
* [TICK] tick-common: Fix one-shot handling in tick_handle_periodic().David S. Miller2007-02-26
| | | | | | | | | | | | 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>
* [TIME] tick-sched: Add missing asm/irq_regs.h include.David S. Miller2007-02-26
| | | | | Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: David S. Miller <davem@davemloft.net>
* [PATCH] NOHZ: Produce debug output instead of a BUG()Thomas Gleixner2007-02-19
| | | | | | | | | 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>
* [PATCH] NOHZ: Fix RCU handlingIngo Molnar2007-02-19
| | | | | | | | | 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>
* [PATCH] Add debugging feature /proc/timer_listIngo Molnar2007-02-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* [PATCH] Add debugging feature /proc/timer_statIngo Molnar2007-02-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* [PATCH] hrtimers: add high resolution timer supportThomas Gleixner2007-02-16
| | | | | | | | | | | | | 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>
* [PATCH] tick-management: dyntick / highres functionalityThomas Gleixner2007-02-16
| | | | | | | | | | | | | | | | | 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>
* [PATCH] tick-management: broadcast functionalityThomas Gleixner2007-02-16
| | | | | | | | | | | | | | | | | 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>
* [PATCH] tick-management: core functionalityThomas Gleixner2007-02-16
| | | | | | | | | | | | | | | 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>
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