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2007-02-16[PATCH] Fix cascade lookup of next_timer_interruptThomas Gleixner
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: 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: 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: Remove the update callbackThomas Gleixner
The clocksource code allows direct updates of the rating of a given clocksource now. Change TSC unstable tracking to use this interface and remove the update callback. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: john stultz <johnstul@us.ibm.com> Cc: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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] GTOD: persistent clock supportJohn Stultz
Persistent clock support: do proper timekeeping across suspend/resume. [bunk@stusta.de: cleanup] Signed-off-by: John Stultz <johnstul@us.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Roman Zippel <zippel@linux-m68k.org> Cc: 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] 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>
2007-02-13[PATCH] x86-64: get rid of ARCH_HAVE_XTIME_LOCKEric Dumazet
ARCH_HAVE_XTIME_LOCK is used by x86_64 arch . This arch needs to place a read only copy of xtime_lock into vsyscall page. This read only copy is named __xtime_lock, and xtime_lock is defined in arch/x86_64/kernel/vmlinux.lds.S as an alias. So the declaration of xtime_lock in kernel/timer.c was guarded by ARCH_HAVE_XTIME_LOCK define, defined to true on x86_64. We can get same result with _attribute__((weak)) in the declaration. linker should do the job. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org>
2007-02-11[PATCH] Common compat_sys_sysinfoKyle McMartin
I noticed that almost all architectures implemented exactly the same sys32_sysinfo... except parisc, where a bug was to be found in handling of the uptime. So let's remove a whole whack of code for fun and profit. Cribbed compat_sys_sysinfo from x86_64's implementation, since I figured it would be the best tested. This patch incorporates Arnd's suggestion of not using set_fs/get_fs, but instead extracting out the common code from sys_sysinfo. Cc: Christoph Hellwig <hch@infradead.org> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-11[PATCH] Numerous fixes to kernel-doc info in source files.Robert P. J. Day
A variety of (mostly) innocuous fixes to the embedded kernel-doc content in source files, including: * make multi-line initial descriptions single line * denote some function names, constants and structs as such * change erroneous opening '/*' to '/**' in a few places * reword some text for clarity Signed-off-by: Robert P. J. Day <rpjday@mindspring.com> Cc: "Randy.Dunlap" <rdunlap@xenotime.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-11[PATCH] use cycle_t instead of u64 in struct time_interpolatorHelge Deller
The 32bit and 64bit PARISC Linux kernels suffers from the problem, that the gettimeofday() call sometimes returns non-monotonic times. The easiest way to fix this, is to drop the PARISC-specific implementation and switch over to the generic TIME_INTERPOLATION framework. But in order to make it even compile on 32bit PARISC, the patch below which touches the generic Linux code, is mandatory. More information and the full patch with the parisc-specific changes is included in this thread: http://lists.parisc-linux.org/pipermail/parisc-linux/2006-December/031003.html As far as I could see, this patch does not change anything for the existing architectures which use this framework (IA64 and SPARC64), since "cycles_t" is defined there as unsigned 64bit-integer anyway (which then makes this patch a no-change for them). Signed-off-by: Helge Deller <deller@gmx.de> Cc: <linux-arch@vger.kernel.org> 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>
2006-12-22[PATCH] schedule_timeout(): improve warning messageAndrew Morton
Kyle is hitting this warning, and we don't have a clue what it's caused by. Add the obligatory dump_stack(). Cc: kyle <kylewong@southa.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-13[PATCH] Optimize calc_load()Eric Dumazet
calc_load() is called by timer interrupt to update avenrun[]. It currently calls nr_active() at each timer tick (HZ per second), while the update of avenrun[] is done only once every 5 seconds. (LOAD_FREQ=5 Hz) nr_active() is quite expensive on SMP machines, since it has to sum up nr_running and nr_uninterruptible of all online CPUS, bringing foreign dirty cache lines. This patch is an optimization of calc_load() so that nr_active() is called only if we need it. The use of unlikely() is welcome since the condition is true only once every 5*HZ time. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Cc: Ingo Molnar <mingo@elte.hu> Acked-by: "Siddha, Suresh B" <suresh.b.siddha@intel.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.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] round_jiffies infrastructureArjan van de Ven
Introduce a round_jiffies() function as well as a round_jiffies_relative() function. These functions round a jiffies value to the next whole second. The primary purpose of this rounding is to cause all "we don't care exactly when" timers to happen at the same jiffy. This avoids multiple timers firing within the second for no real reason; with dynamic ticks these extra timers cause wakeups from deep sleep CPU sleep states and thus waste power. The exact wakeup moment is skewed by the cpu number, to avoid all cpus from waking up at the exact same time (and hitting the same lock/cachelines there) [akpm@osdl.org: fix variable type] Signed-off-by: Arjan van de Ven <arjan@linux.intel.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>
2006-10-01[PATCH] kill wall_jiffiesAtsushi Nemoto
With 2.6.18-rc4-mm2, now wall_jiffies will always be the same as jiffies. So we can kill wall_jiffies completely. This is just a cleanup and logically should not change any real behavior except for one thing: RTC updating code in (old) ppc and xtensa use a condition "jiffies - wall_jiffies == 1". This condition is never met so I suppose it is just a bug. I just remove that condition only instead of kill the whole "if" block. [heiko.carstens@de.ibm.com: s390 build fix and cleanup] Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Cc: Andi Kleen <ak@muc.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Ian Molton <spyro@f2s.com> Cc: Mikael Starvik <starvik@axis.com> Cc: David Howells <dhowells@redhat.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Hirokazu Takata <takata.hirokazu@renesas.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Kazumoto Kojima <kkojima@rr.iij4u.or.jp> Cc: Richard Curnow <rc@rc0.org.uk> Cc: William Lee Irwin III <wli@holomorphy.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Cc: Miles Bader <uclinux-v850@lsi.nec.co.jp> Cc: Chris Zankel <chris@zankel.net> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: Heiko Carstens <heiko.carstens@de.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: add ntp_update_frequencyRoman Zippel
This introduces ntp_update_frequency() and deinlines ntp_clear() (as it's not performance critical). ntp_update_frequency() calculates the base tick length using tick_usec and adds a base adjustment, in case the frequency doesn't divide evenly by HZ. 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: Move all the NTP related code to ntp.cjohn stultz
Move all the NTP related code to ntp.c [akpm@osdl.org: cleanups, build fix] Signed-off-by: John Stultz <johnstul@us.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29[PATCH] simplify update_times (avoid jiffies/jiffies_64 aliasing problem)Atsushi Nemoto
Pass ticks to do_timer() and update_times(), and adjust x86_64 and s390 timer interrupt handler with this change. Currently update_times() calculates ticks by "jiffies - wall_jiffies", but callers of do_timer() should know how many ticks to update. Passing ticks get rid of this redundant calculation. Also there are another redundancy pointed out by Martin Schwidefsky. This cleanup make a barrier added by 5aee405c662ca644980c184774277fc6d0769a84 needless. So this patch removes it. As a bonus, this cleanup make wall_jiffies can be removed easily, since now wall_jiffies is always synced with jiffies. (This patch does not really remove wall_jiffies. It would be another cleanup patch) Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: john stultz <johnstul@us.ibm.com> Cc: Andi Kleen <ak@muc.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Acked-by: Russell King <rmk@arm.linux.org.uk> Cc: Ian Molton <spyro@f2s.com> Cc: Mikael Starvik <starvik@axis.com> Acked-by: David Howells <dhowells@redhat.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Hirokazu Takata <takata.hirokazu@renesas.com> Acked-by: Ralf Baechle <ralf@linux-mips.org> Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Kazumoto Kojima <kkojima@rr.iij4u.or.jp> Cc: Richard Curnow <rc@rc0.org.uk> Cc: William Lee Irwin III <wli@holomorphy.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Cc: Miles Bader <uclinux-v850@lsi.nec.co.jp> Cc: Chris Zankel <chris@zankel.net> Acked-by: "Luck, Tony" <tony.luck@intel.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29[PATCH] check return value of cpu_callbackAkinobu Mita
Spawing ksoftirqd, migration, or watchdog, and calling init_timers_cpu() may fail with small memory. If it happens in initcalls, kernel NULL pointer dereference happens later. This patch makes crash happen immediately in such cases. It seems a bit better than getting kernel NULL pointer dereference later. Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Akinobu Mita <mita@miraclelinux.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29[PATCH] Fix kerneldoc comments in kernel/timer.cRolf Eike Beer
Some of the kerneldoc comments in this file are ignored since the lead-in is malformed, using either "/*" or "/***" instead of "/**". [rdunlap@xenotime.net: kerneldoc fixes] Signed-off-by: Rolf Eike Beer <eike-kernel@sf-tec.de> Acked-by: Alan Cox <alan@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29[PATCH] timer: add lock annotation to lock_timer_baseJosh Triplett
lock_timer_base acquires a lock and returns with that lock held. Add a lock annotation to this function so that sparse can check callers for lock pairing, and so that sparse will not complain about this function since it intentionally uses the lock in this manner. Signed-off-by: Josh Triplett <josh@freedesktop.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-08-14[PATCH] sys_getppid oopses on debug kernelKirill Korotaev
sys_getppid() optimization can access a freed memory. On kernels with DEBUG_SLAB turned ON, this results in Oops. As Dave Hansen noted, this optimization is also unsafe for memory hotplug. So this patch always takes the lock to be safe. [oleg@tv-sign.ru: simplifications] Signed-off-by: Kirill Korotaev <dev@openvz.org> Cc: <stable@kernel.org> Cc: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-07-31[PATCH] timer: Fix tvec_bases initializerJosh Triplett
kernel/timer.c defines a (per-cpu) pointer to tvec_base_t, but initializes it using { &a_tvec_base_t }, which sparse warns about; change this to just &a_tvec_base_t. Signed-off-by: Josh Triplett <josh@freedesktop.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-31[PATCH] fix bad macro param in timer.cSteven Rostedt
We have #define INDEX(N) (base->timer_jiffies >> (TVR_BITS + N * TVN_BITS)) & TVN_MASK and it's used via list = varray[i + 1]->vec + (INDEX(i + 1)); So, due to underparenthesisation, this INDEX(i+1) is now a ... (TVR_BITS + i + 1 * TVN_BITS)) ... So this bugfix changes behaviour. It worked before by sheer luck: "If i was anything but 0, it was broken. But this was only used by s390 and arm. Since it was for the next interrupt, could that next interrupt be a problem (going into the second cascade)? But it was probably seldom wrong. That is, this would fail if the next interrupt was in the second cascade, and was wrapped. Which may never of happened. Also if it did happen, it would have just missed the interrupt. If an interrupt was missed, and no one was there to miss it, was it really missed :-)" Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-31[PATCH] cpu hotplug: replace __devinit* with __cpuinit* for cpu notificationsChandra Seetharaman
Few of the callback functions and notifier blocks that are associated with cpu notifications incorrectly have __devinit and __devinitdata. They should be __cpuinit and __cpuinitdata instead. It makes no functional difference but wastes text area when CONFIG_HOTPLUG is enabled and CONFIG_HOTPLUG_CPU is not. This patch fixes all those instances. Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Cc: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-14[PATCH] improve timekeeping resume robustnessjohn stultz
Resolve problems seen w/ APM suspend. Due to resume initialization ordering, its possible we could get a timer interrupt before the timekeeping resume() function is called. This patch ensures we don't do any timekeeping accounting before we're fully resumed. (akpm: fixes the machine-freezes-on-APM-resume bug) Signed-off-by: John Stultz <johnstul@us.ibm.com> Cc: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-14[PATCH] del_timer_sync(): add cpu_relax()Andrew Morton
Relax the CPU in the del_timer_sync() busywait loop. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-10[PATCH] adjust clock for lost ticksRoman Zippel
A large number of lost ticks can cause an overadjustment of the clock. To compensate for this we look at the current error and the larger the error already is the more careful we are at adjusting the error. As small extra fix reset the error when the clock is set. Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Acked-by: john stultz <johnstul@us.ibm.com> Cc: Uwe Bugla <uwe.bugla@gmx.de> Cc: James Bottomley <James.Bottomley@SteelEye.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03[PATCH] sched: cleanup, remove task_t, convert to struct task_structIngo Molnar
cleanup: remove task_t and convert all the uses to struct task_struct. I introduced it for the scheduler anno and it was a mistake. Conversion was mostly scripted, the result was reviewed and all secondary whitespace and style impact (if any) was fixed up by hand. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03[PATCH] lockdep: annotate timer base locksIngo Molnar
Split the per-CPU timer base locks up into separate lock classes, because they are used recursively. Has no effect on non-lockdep kernels. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03[PATCH] lockdep: locking init debugging improvementIngo Molnar
Locking init improvement: - introduce and use __SPIN_LOCK_UNLOCKED for array initializations, to pass in the name string of locks, used by debugging Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27[PATCH] cpu hotplug: revert initdata patch submitted for 2.6.17Chandra Seetharaman
This patch reverts notifier_block changes made in 2.6.17 Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Cc: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27[PATCH] cpu hotplug: revert init patch submitted for 2.6.17Chandra Seetharaman
In 2.6.17, there was a problem with cpu_notifiers and XFS. I provided a band-aid solution to solve that problem. In the process, i undid all the changes you both were making to ensure that these notifiers were available only at init time (unless CONFIG_HOTPLUG_CPU is defined). We deferred the real fix to 2.6.18. Here is a set of patches that fixes the XFS problem cleanly and makes the cpu notifiers available only at init time (unless CONFIG_HOTPLUG_CPU is defined). If CONFIG_HOTPLUG_CPU is defined then cpu notifiers are available at run time. This patch reverts the notifier_call changes made in 2.6.17 Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Cc: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] fix and optimize clock source updateRoman Zippel
This fixes the clock source updates in update_wall_time() to correctly track the time coming in via current_tick_length(). Optimize the fast paths to be as short as possible to keep the overhead low. Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Acked-by: John Stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] time: rename clocksource functionsjohn stultz
As suggested by Roman Zippel, change clocksource functions to use clocksource_xyz rather then xyz_clocksource to avoid polluting the namespace. Signed-off-by: John Stultz <johnstul@us.ibm.com> Cc: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] Time: Introduce arch generic time accessorsjohn stultz
Introduces clocksource switching code and the arch generic time accessor functions that use the clocksource infrastructure. Signed-off-by: John Stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] Time: Use clocksource abstraction for NTP adjustmentsjohn stultz
Instead of incrementing xtime by tick_nsec + ntp adjustments, use the clocksource abstraction to increment and scale time. Using the clocksource abstraction allows other clocksources to be used consistently in the face of late or lost ticks, while preserving the existing behavior via the jiffies clocksource. This removes the need to keep time_phase adjustments as we just use the current_tick_length() function as the NTP interface and accumulate time using shifted nanoseconds. The basics of this design was by Roman Zippel, however it is my own interpretation and implementation, so the credit should go to him and the blame to me. Signed-off-by: John Stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] Time: Let user request precision from current_tick_length()john stultz
Change the current_tick_length() function so it takes an argument which specifies how much precision to return in shifted nanoseconds. This provides a simple way to convert between NTPs internal nanoseconds shifted by (SHIFT_SCALE - 10) to other shifted nanosecond units that are used by the clocksource abstraction. Signed-off-by: John Stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] Time: Use clocksource infrastructure for update_wall_timejohn stultz
Modify the update_wall_time function so it increments time using the clocksource abstraction instead of jiffies. Since the only clocksource driver currently provided is the jiffies clocksource, this should result in no functional change. Additionally, a timekeeping_init and timekeeping_resume function has been added to initialize and maintain some of the new timekeping state. [hirofumi@mail.parknet.co.jp: fixlet] Signed-off-by: John Stultz <johnstul@us.ibm.com> Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-25[PATCH] Define __raw_get_cpu_var and use itPaul Mackerras
There are several instances of per_cpu(foo, raw_smp_processor_id()), which is semantically equivalent to __get_cpu_var(foo) but without the warning that smp_processor_id() can give if CONFIG_DEBUG_PREEMPT is enabled. For those architectures with optimized per-cpu implementations, namely ia64, powerpc, s390, sparc64 and x86_64, per_cpu() turns into more and slower code than __get_cpu_var(), so it would be preferable to use __get_cpu_var on those platforms. This defines a __raw_get_cpu_var(x) macro which turns into per_cpu(x, raw_smp_processor_id()) on architectures that use the generic per-cpu implementation, and turns into __get_cpu_var(x) on the architectures that have an optimized per-cpu implementation. Signed-off-by: Paul Mackerras <paulus@samba.org> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23[PATCH] When CONFIG_BASE_SMALL=1, cascade() may enter an infinite loopPorpoise
When CONFIG_BASE_SAMLL=1, cascade() in may enter the infinite loop. Because of CONFIG_BASE_SMALL=1(TVR_BITS=6 and TVN_BITS=4), the list base->tv5 may cascade into base->tv5. So, the kernel enters the infinite loop in the function cascade(). I created a test module to verify this bug, and a patch to fix it. #include <linux/kernel.h> #include <linux/module.h> #include <linux/init.h> #include <linux/timer.h> #if 0 #include <linux/kdb.h> #else #define kdb_printf printk #endif #define TVN_BITS (CONFIG_BASE_SMALL ? 4 : 6) #define TVR_BITS (CONFIG_BASE_SMALL ? 6 : 8) #define TVN_SIZE (1 << TVN_BITS) #define TVR_SIZE (1 << TVR_BITS) #define TVN_MASK (TVN_SIZE - 1) #define TVR_MASK (TVR_SIZE - 1) #define TV_SIZE(N) (N*TVN_BITS + TVR_BITS) struct timer_list timer0; struct timer_list dummy_timer1; struct timer_list dummy_timer2; void dummy_timer_fun(unsigned long data) { } unsigned long j=0; void check_timer_base(unsigned long data) { kdb_printf("check_timer_base %08x\n",jiffies); mod_timer(&timer0,(jiffies & (~0xFFF)) + 0x1FFF); } int init_module(void) { init_timer(&timer0); timer0.data = (unsigned long)0; timer0.function = check_timer_base; mod_timer(&timer0,jiffies+1); init_timer(&dummy_timer1); dummy_timer1.data = (unsigned long)0; dummy_timer1.function = dummy_timer_fun; init_timer(&dummy_timer2); dummy_timer2.data = (unsigned long)0; dummy_timer2.function = dummy_timer_fun; j=jiffies; j&=(~((1<<TV_SIZE(3))-1)); j+=(1<<TV_SIZE(3)); j+=(1<<TV_SIZE(4)); kdb_printf("mod_timer %08x\n",j); mod_timer(&dummy_timer1, j ); mod_timer(&dummy_timer2, j ); return 0; } void cleanup_module() { del_timer_sync(&timer0); del_timer_sync(&dummy_timer1); del_timer_sync(&dummy_timer2); } (Cleanups from Oleg) [oleg@tv-sign.ru: use list_replace_init()] Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Matt Mackall <mpm@selenic.com> Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23[PATCH] list: use list_replace_init() instead of list_splice_init()Oleg Nesterov
list_splice_init(list, head) does unneeded job if it is known that list_empty(head) == 1. We can use list_replace_init() instead. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-21[PATCH] Fix a NO_IDLE_HZ timer bugZachary Amsden
Under certain timing conditions, a race during boot occurs where timer ticks are being processed on remote CPUs. The remote timer ticks can increment jiffies, and if this happens during a window when a timeout is very close to expiring but a local tick has not yet been delivered, you can end up with 1) No softirq pending 2) A local timer wheel which is not synced to jiffies 3) No high resolution timer active 4) A local timer which is supposed to fire before the current jiffies value. In this circumstance, the comparison in next_timer_interrupt overflows, because the base of the comparison for high resolution timers is jiffies, but for the softirq timer wheel, it is relative the the current base of the wheel (jiffies_base). Signed-off-by: Zachary Amsden <zach@vmware.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-26[PATCH] Remove __devinit and __cpuinit from notifier_call definitionsChandra Seetharaman
Few of the notifier_chain_register() callers use __init in the definition of notifier_call. It is incorrect as the function definition should be available after the initializations (they do not unregister them during initializations). This patch fixes all such usages to _not_ have the notifier_call __init section. Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-26[PATCH] Remove __devinitdata from notifier block definitionsChandra Seetharaman
Few of the notifier_chain_register() callers use __devinitdata in the definition of notifier_block data structure. It is incorrect as the data structure should be available after the initializations (they do not unregister them during initializations). This was leading to an oops when notifier_chain_register() call is invoked for those callback chains after initialization. This patch fixes all such usages to _not_ have the notifier_block data structure in the init data section. Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-11[PATCH] timer initialisation fixAndrew Morton
We need the boot CPU's tvec_bases[] entry to be initialised super-early in boot, for early_serial_setup(). That runs within setup_arch(), before even per-cpu areas are initialised. The patch changes tvec_bases to use compile-time initialisation, and adds a separate array `tvec_base_done' to keep track of which CPU has had its tvec_bases[] entry initialised (because we can no longer use the zeroness of that tvec_bases[] entry to determine whether it has been initialised). Thanks to Eugene Surovegin <ebs@ebshome.net> for diagnosing this. Cc: Eugene Surovegin <ebs@ebshome.net> Cc: Jan Beulich <jbeulich@novell.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-09[PATCH] x86_64: Fix drift with HPET timer enabledJordan Hargrave
If the HPET timer is enabled, the clock can drift by ~3 seconds a day. This is due to the HPET timer not being initialized with the correct setting (still using PIT count). If HZ changes, this drift can become even more pronounced. HPET patch initializes tick_nsec with correct tick_nsec settings for HPET timer. Vojtech comments: "It's not entirely correct (it assumes the HPET ticks totally exactly), but it's significantly better than assuming the PIT error there." Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-02BUG_ON() Conversion in kernel/signal.cEric Sesterhenn
this changes if() BUG(); constructs to BUG_ON() which is cleaner, contains unlikely() and can better optimized away. Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-03-31[PATCH] sched: reduce overhead of calc_loadJack Steiner
Currently, count_active_tasks() calls both nr_running() & nr_interruptible(). Each of these functions does a "for_each_cpu" & reads values from the runqueue of each cpu. Although this is not a lot of instructions, each runqueue may be located on different node. Depending on the architecture, a unique TLB entry may be required to access each runqueue. Since there may be more runqueues than cpu TLB entries, a scan of all runqueues can trash the TLB. Each memory reference incurs a TLB miss & refill. In addition, the runqueue cacheline that contains nr_running & nr_uninterruptible may be evicted from the cache between the two passes. This causes unnecessary cache misses. Combining nr_running() & nr_interruptible() into a single function substantially reduces the TLB & cache misses on large systems. This should have no measureable effect on smaller systems. On a 128p IA64 system running a memory stress workload, the new function reduced the overhead of calc_load() from 605 usec/call to 324 usec/call. Signed-off-by: Jack Steiner <steiner@sgi.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>