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* Merge branch 'devel' of master.kernel.org:/home/rmk/linux-2.6-armLinus Torvalds2011-01-061-0/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm: (416 commits) ARM: DMA: add support for DMA debugging ARM: PL011: add DMA burst threshold support for ST variants ARM: PL011: Add support for transmit DMA ARM: PL011: Ensure IRQs are disabled in UART interrupt handler ARM: PL011: Separate hardware FIFO size from TTY FIFO size ARM: PL011: Allow better handling of vendor data ARM: PL011: Ensure error flags are clear at startup ARM: PL011: include revision number in boot-time port printk ARM: vexpress: add sched_clock() for Versatile Express ARM i.MX53: Make MX53 EVK bootable ARM i.MX53: Some bug fix about MX53 MSL code ARM: 6607/1: sa1100: Update platform device registration ARM: 6606/1: sa1100: Fix platform device registration ARM i.MX51: rename IPU irqs ARM i.MX51: Add ipu clock support ARM: imx/mx27_3ds: Add PMIC support ARM: DMA: Replace page_to_dma()/dma_to_page() with pfn_to_dma()/dma_to_pfn() mx51: fix usb clock support MX51: Add support for usb host 2 arch/arm/plat-mxc/ehci.c: fix errors/typos ...
| * Fix rounding in clocks_calc_mult_shift()john stultz2010-12-221-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Russell King reports: | On the ARM dev boards, we have a 32-bit counter running at 24MHz. Calling | clocks_calc_mult_shift(&mult, &shift, 24MHz, NSEC_PER_SEC, 60) gives | us a multiplier of 2796202666 and a shift of 26. | | Over a large counter delta, this produces an error - lets take a count | from 362976315 to 4280663372: | | (4280663372-362976315) * 2796202666 / 2^26 - (4280663372-362976315) * (1000/24) | => -38.91872422891230269990 | | Can we do better? | | (4280663372-362976315) * 2796202667 / 2^26 - (4280663372-362976315) * (1000/24) | 19.45936211449532822051 | | which is about twice as good as the 2796202666 multiplier. | | Looking at the equivalent divisions obtained, 2796202666 / 2^26 gives | 41.66666665673255920410ns per tick, whereas 2796202667 / 2^26 gives | 41.66666667163372039794ns. The actual value wanted is 1000/24 = | 41.66666666666666666666ns. Fix this by ensuring we round to nearest when calculating the multiplier. Signed-off-by: John Stultz <john.stultz@linaro.org> Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Tested-by: Will Deacon <will.deacon@arm.com> Tested-by: Mikael Pettersson <mikpe@it.uu.se> Tested-by: Eric Miao <eric.y.miao@gmail.com> Tested-by: Olof Johansson <olof@lixom.net> Tested-by: Jamie Iles <jamie@jamieiles.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* | hrtimers: Convert hrtimers to use timerlist infrastructureJohn Stultz2010-12-101-4/+4
| | | | | | | | | | | | | | | | | | | | | | Converts the hrtimer code to use the new timerlist infrastructure Signed-off-by: John Stultz <john.stultz@linaro.org> LKML Reference: <1290136329-18291-3-git-send-email-john.stultz@linaro.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> CC: Alessandro Zummo <a.zummo@towertech.it> CC: Thomas Gleixner <tglx@linutronix.de> CC: Richard Cochran <richardcochran@gmail.com>
* | time: Use ARRAY_SIZE macro in timecompare.cNikitas Angelinas2010-10-211-2/+3
| | | | | | | | | | | | | | | | | | Replace sizeof(buffer)/sizeof(buffer[0]) with ARRAY_SIZE(buffer) in kernel/time/timecompare.c Signed-off-by: Nikitas Angelinas <nikitasangelinas@googlemail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | time: Compensate for rounding on odd-frequency clocksourcesKasper Pedersen2010-10-211-2/+7
|/ | | | | | | | | | | | | | | | | | | | | | | | | When the clocksource is not a multiple of HZ, the clock will be off. For acpi_pm, HZ=1000 the error is 127.111 ppm: The rounding of cycle_interval ends up generating a false error term in ntp_error accumulation since xtime_interval is not exactly 1/HZ. So, we subtract out the error caused by the rounding. This has been visible since 2.6.32-rc2 commit a092ff0f90cae22b2ac8028ecd2c6f6c1a9e4601 time: Implement logarithmic time accumulation That commit raised NTP_INTERVAL_FREQ and exposed the rounding error. testing tool: http://n1.taur.dk/permanent/testpmt.c Also tested with ntpd and a frequency counter. Signed-off-by: Kasper Pedersen <kkp2010@kasperkp.dk> Acked-by: john stultz <johnstul@us.ibm.com> Cc: John Kacur <jkacur@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* ntp: Clamp PLL update intervalMiroslav Lichvar2010-09-091-3/+11
| | | | | | | | | | | | | | | Clamp update interval to reduce PLL gain with low sampling rate (e.g. intermittent network connection) to avoid instability. The clamp roughly corresponds to the loop time constant, it's 8 * poll interval for SHIFT_PLL 2 and 32 * poll interval for SHIFT_PLL 4. This gives good results without affecting the gain in normal conditions where ntpd skips only up to seven consecutive samples. Signed-off-by: Miroslav Lichvar <mlichvar@redhat.com> Acked-by: john stultz <johnstul@us.ibm.com> LKML-Reference: <1283870626-9472-1-git-send-email-mlichvar@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* time: Workaround gcc loop optimization that causes 64bit div errorsJohn Stultz2010-08-131-3/+4
| | | | | | | | | | | | | | | | | | | | | Early 4.3 versions of gcc apparently aggressively optimize the raw time accumulation loop, replacing it with a divide. On 32bit systems, this causes the following link errors: undefined reference to `__umoddi3' undefined reference to `__udivdi3' The gcc issue has been fixed in 4.4 and greater. This patch replaces the accumulation loop with a do_div, as suggested by Linus. Signed-off-by: John Stultz <johnstul@us.ibm.com> CC: Jason Wessel <jason.wessel@windriver.com> CC: Larry Finger <Larry.Finger@lwfinger.net> CC: Ingo Molnar <mingo@elte.hu> CC: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* timekeeping: Fix overflow in rawtime tv_nsec on 32 bit archsJason Wessel2010-08-121-4/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | The tv_nsec is a long and when added to the shifted interval it can wrap and become negative which later causes looping problems in the getrawmonotonic(). The edge case occurs when the system has slept for a short period of time of ~2 seconds. A trace printk of the values in this patch illustrate the problem: ftrace time stamp: log 43.716079: logarithmic_accumulation: raw: 3d0913 tv_nsec d687faa 43.718513: logarithmic_accumulation: raw: 3d0913 tv_nsec da588bd 43.722161: logarithmic_accumulation: raw: 3d0913 tv_nsec de291d0 46.349925: logarithmic_accumulation: raw: 7a122600 tv_nsec e1f9ae3 46.349930: logarithmic_accumulation: raw: 1e848980 tv_nsec 8831c0e3 The kernel starts looping at 46.349925 in the getrawmonotonic() due to the negative value from adding the raw value to tv_nsec. A simple solution is to accumulate into a u64, and then normalize it to a timespec_t. Signed-off-by: Jason Wessel <jason.wessel@windriver.com> [ Reworked variable names and simplified some of the code. - John ] Signed-off-by: John Stultz <johnstul@us.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'timers-timekeeping-for-linus' of ↵Linus Torvalds2010-08-063-68/+48
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers-timekeeping-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: um: Fix read_persistent_clock fallout kgdb: Do not access xtime directly powerpc: Clean up obsolete code relating to decrementer and timebase powerpc: Rework VDSO gettimeofday to prevent time going backwards clocksource: Add __clocksource_updatefreq_hz/khz methods x86: Convert common clocksources to use clocksource_register_hz/khz timekeeping: Make xtime and wall_to_monotonic static hrtimer: Cleanup direct access to wall_to_monotonic um: Convert to use read_persistent_clock timkeeping: Fix update_vsyscall to provide wall_to_monotonic offset powerpc: Cleanup xtime usage powerpc: Simplify update_vsyscall time: Kill off CONFIG_GENERIC_TIME time: Implement timespec_add x86: Fix vtime/file timestamp inconsistencies Trivial conflicts in Documentation/feature-removal-schedule.txt Much less trivial conflicts in arch/powerpc/kernel/time.c resolved as per Thomas' earlier merge commit 47916be4e28c ("Merge branch 'powerpc.cherry-picks' into timers/clocksource")
| * clocksource: Add __clocksource_updatefreq_hz/khz methodsJohn Stultz2010-07-271-5/+24
| | | | | | | | | | | | | | | | | | | | | | | | To properly handle clocksources that change frequencies at the clocksource->enable() point, this patch adds a method that will update the clocksource's mult/shift and max_idle_ns values. Signed-off-by: John Stultz <johnstul@us.ibm.com> LKML-Reference: <1279068988-21864-12-git-send-email-johnstul@us.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * timekeeping: Make xtime and wall_to_monotonic staticJohn Stultz2010-07-271-2/+2
| | | | | | | | | | | | | | | | | | | | | | This patch makes xtime and wall_to_monotonic static, as planned in Documentation/feature-removal-schedule.txt. This will allow for further cleanups to the timekeeping core. Signed-off-by: John Stultz <johnstul@us.ibm.com> LKML-Reference: <1279068988-21864-10-git-send-email-johnstul@us.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * hrtimer: Cleanup direct access to wall_to_monotonicJohn Stultz2010-07-271-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | Provides an accessor function to replace hrtimer.c's direct access of wall_to_monotonic. This will allow wall_to_monotonic to be made static as planned in Documentation/feature-removal-schedule.txt Signed-off-by: John Stultz <johnstul@us.ibm.com> LKML-Reference: <1279068988-21864-9-git-send-email-johnstul@us.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * timkeeping: Fix update_vsyscall to provide wall_to_monotonic offsetJohn Stultz2010-07-271-3/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | update_vsyscall() did not provide the wall_to_monotoinc offset, so arch specific implementations tend to reference wall_to_monotonic directly. This limits future cleanups in the timekeeping core, so this patch fixes the update_vsyscall interface to provide wall_to_monotonic, allowing wall_to_monotonic to be made static as planned in Documentation/feature-removal-schedule.txt Signed-off-by: John Stultz <johnstul@us.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Anton Blanchard <anton@samba.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Tony Luck <tony.luck@intel.com> LKML-Reference: <1279068988-21864-7-git-send-email-johnstul@us.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * time: Kill off CONFIG_GENERIC_TIMEJohn Stultz2010-07-273-55/+8
| | | | | | | | | | | | | | | | | | | | Now that all arches have been converted over to use generic time via clocksources or arch_gettimeoffset(), we can remove the GENERIC_TIME config option and simplify the generic code. Signed-off-by: John Stultz <johnstul@us.ibm.com> LKML-Reference: <1279068988-21864-4-git-send-email-johnstul@us.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * time: Implement timespec_addJohn Stultz2010-07-271-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | After accidentally misusing timespec_add_safe, I wanted to make sure we don't accidently trip over that issue again, so I created a simple timespec_add() function which we can use to replace the instances of timespec_add_safe() that don't want the overflow detection. Signed-off-by: John Stultz <johnstul@us.ibm.com> LKML-Reference: <1279068988-21864-3-git-send-email-johnstul@us.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | Merge branch 'timers-for-linus' of ↵Linus Torvalds2010-08-061-5/+0
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: Documentation: Add timers/timers-howto.txt timer: Added usleep_range timer Revert "timer: Added usleep[_range] timer" clockevents: Remove the per cpu tick skew posix_timer: Move copy_to_user(created_timer_id) down in timer_create() timer: Added usleep[_range] timer timers: Document meaning of deferrable timer
| * | clockevents: Remove the per cpu tick skewArjan van de Ven2010-08-021-5/+0
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Historically, Linux has tried to make the regular timer tick on the various CPUs not happen at the same time, to avoid contention on xtime_lock. Nowadays, with the tickless kernel, this contention no longer happens since time keeping and updating are done differently. In addition, this skew is actually hurting power consumption in a measurable way on many-core systems. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> LKML-Reference: <20100727210210.58d3118c@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | Merge branch 'sched-core-for-linus' of ↵Linus Torvalds2010-08-061-8/+2
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (27 commits) sched: Use correct macro to display sched_child_runs_first in /proc/sched_debug sched: No need for bootmem special cases sched: Revert nohz_ratelimit() for now sched: Reduce update_group_power() calls sched: Update rq->clock for nohz balanced cpus sched: Fix spelling of sibling sched, cpuset: Drop __cpuexit from cpu hotplug callbacks sched: Fix the racy usage of thread_group_cputimer() in fastpath_timer_check() sched: run_posix_cpu_timers: Don't check ->exit_state, use lock_task_sighand() sched: thread_group_cputime: Simplify, document the "alive" check sched: Remove the obsolete exit_state/signal hacks sched: task_tick_rt: Remove the obsolete ->signal != NULL check sched: __sched_setscheduler: Read the RLIMIT_RTPRIO value lockless sched: Fix comments to make them DocBook happy sched: Fix fix_small_capacity powerpc: Exclude arch_sd_sibiling_asym_packing() on UP powerpc: Enable asymmetric SMT scheduling on POWER7 sched: Add asymmetric group packing option for sibling domain sched: Fix capacity calculations for SMT4 sched: Change nohz idle load balancing logic to push model ...
| * \ Merge branch 'sched/urgent' into sched/coreIngo Molnar2010-08-051-1/+1
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: include/linux/sched.h Merge reason: Add the leftover .35 urgent bits, fix the conflict. Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | sched: Revert nohz_ratelimit() for nowPeter Zijlstra2010-07-171-1/+1
| | |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Norbert reported that nohz_ratelimit() causes his laptop to burn about 4W (40%) extra. For now back out the change and see if we can adjust the power management code to make better decisions. Reported-by: Norbert Preining <preining@logic.at> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Mike Galbraith <efault@gmx.de> Cc: Arjan van de Ven <arjan@infradead.org> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | Merge branch 'linus' into sched/coreIngo Molnar2010-07-211-12/+9
| |\ \ | | |/ | | | | | | | | | | | | Merge reason: Move from the -rc3 to the almost-rc6 base. Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | sched: Change nohz idle load balancing logic to push modelVenkatesh Pallipadi2010-06-091-7/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the new push model, all idle CPUs indeed go into nohz mode. There is still the concept of idle load balancer (performing the load balancing on behalf of all the idle cpu's in the system). Busy CPU kicks the nohz balancer when any of the nohz CPUs need idle load balancing. The kickee CPU does the idle load balancing on behalf of all idle CPUs instead of the normal idle balance. This addresses the below two problems with the current nohz ilb logic: * the idle load balancer continued to have periodic ticks during idle and wokeup frequently, even though it did not have any rebalancing to do on behalf of any of the idle CPUs. * On x86 and CPUs that have APIC timer stoppage on idle CPUs, this periodic wakeup can result in a periodic additional interrupt on a CPU doing the timer broadcast. Also currently we are migrating the unpinned timers from an idle to the cpu doing idle load balancing (when all the cpus in the system are idle, there is no idle load balancing cpu and timers get added to the same idle cpu where the request was made. So the existing optimization works only on semi idle system). And In semi idle system, we no longer have periodic ticks on the idle load balancer CPU. Using that cpu will add more delays to the timers than intended (as that cpu's timer base may not be uptodate wrt jiffies etc). This was causing mysterious slowdowns during boot etc. For now, in the semi idle case, use the nearest busy cpu for migrating timers from an idle cpu. This is good for power-savings anyway. Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <1274486981.2840.46.camel@sbs-t61.sc.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | Merge branch 'master' into for-nextJiri Kosina2010-08-041-12/+9
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| * | Merge branch 'sched-fixes-for-linus' of ↵Linus Torvalds2010-07-021-8/+8
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched: Cure nr_iowait_cpu() users init: Fix comment init, sched: Fix race between init and kthreadd
| | * | sched: Cure nr_iowait_cpu() usersPeter Zijlstra2010-07-011-8/+8
| | |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 0224cf4c5e (sched: Intoduce get_cpu_iowait_time_us()) broke things by not making sure preemption was indeed disabled by the callers of nr_iowait_cpu() which took the iowait value of the current cpu. This resulted in a heap of preempt warnings. Cure this by making nr_iowait_cpu() take a cpu number and fix up the callers to pass in the right number. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arjan van de Ven <arjan@infradead.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Maxim Levitsky <maximlevitsky@gmail.com> Cc: Len Brown <len.brown@intel.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Jiri Slaby <jslaby@suse.cz> Cc: linux-pm@lists.linux-foundation.org LKML-Reference: <1277968037.1868.120.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | nohz: Fix nohz ratelimitPeter Zijlstra2010-06-171-4/+1
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Chris Wedgwood reports that 39c0cbe (sched: Rate-limit nohz) causes a serial console regression, unresponsiveness, and indeed it does. The reason is that the nohz code is skipped even when the tick was already stopped before the nohz_ratelimit(cpu) condition changed. Move the nohz_ratelimit() check to the other conditions which prevent long idle sleeps. Reported-by: Chris Wedgwood <cw@f00f.org> Tested-by: Brian Bloniarz <bmb@athenacr.com> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Greg KH <gregkh@suse.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Cc: Jef Driesen <jefdriesen@telenet.be> LKML-Reference: <1276790557.27822.516.camel@twins> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | fix comment/printk typos concerning "already"Uwe Kleine-König2010-07-111-1/+1
|/ | | | | Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* Merge branch 'timers-for-linus' of ↵Linus Torvalds2010-05-193-20/+65
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: clocksource: Add clocksource_register_hz/khz interface posix-cpu-timers: Optimize run_posix_cpu_timers() time: Remove xtime_cache mqueue: Convert message queue timeout to use hrtimers hrtimers: Provide schedule_hrtimeout for CLOCK_REALTIME timers: Introduce the concept of timer slack for legacy timers ntp: Remove tickadj ntp: Make time_adjust static time: Add xtime, wall_to_monotonic to feature-removal-schedule timer: Try to survive timer callback preempt_count leak timer: Split out timer function call timer: Print function name for timer callbacks modifying preemption count time: Clean up warp_clock() cpu-timers: Avoid iterating over all threads in fastpath_timer_check() cpu-timers: Change SIGEV_NONE timer implementation cpu-timers: Return correct previous timer reload value cpu-timers: Cleanup arm_timer() cpu-timers: Simplify RLIMIT_CPU handling
| * clocksource: Add clocksource_register_hz/khz interfaceJohn Stultz2010-05-101-0/+48
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | How to pick good mult/shift pairs has always been difficult to describe to folks writing clocksource drivers, since it requires careful tradeoffs in adjustment accuracy vs overflow limits. Now, with the clocks_calc_mult_shift function, its much easier. However, not many clocksources have converted to using that function, and there is still the issue of the max interval length assumption being made by each clocksource driver independently. So this patch simplifies the registration process by having clocksources be registered with a hz/khz value and the registration function taking care of setting mult/shift. This should take most of the confusion out of writing a clocksource driver. Additionally it also keeps the shift size tradeoff (more accuracy vs longer possible nohz times) centralized so the timekeeping core can keep track of the assumptions being made. [ tglx: Coding style and comments fixed ] Signed-off-by: John Stultz <johnstul@us.ibm.com> LKML-Reference: <1273280858-30143-1-git-send-email-johnstul@us.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * Merge branch 'linus' into timers/coreThomas Gleixner2010-05-104-14/+45
| |\ | | | | | | | | | | | | | | | Reason: Further posix_cpu_timer patches depend on mainline changes Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | time: Remove xtime_cacheJohn Stultz2010-04-131-19/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With the earlier logarithmic time accumulation patch, xtime will now always be within one "tick" of the current time, instead of possibly half a second off. This removes the need for the xtime_cache value, which always stored the time at the last interrupt, so this patch cleans that up removing the xtime_cache related code. This patch also addresses an issue with an earlier version of this change, where xtime_cache was normalizing xtime, which could in some cases be not valid (ie: tv_nsec == NSEC_PER_SEC). This is fixed by handling the edge case in update_wall_time(). Signed-off-by: John Stultz <johnstul@us.ibm.com> Cc: Petr Titěra <P.Titera@century.cz> LKML-Reference: <1270589451-30773-1-git-send-email-johnstul@us.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | ntp: Make time_adjust staticJohn Stultz2010-03-231-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | Now that no arches are accessing time_adjust directly, make it static. Signed-off-by: John Stultz <johnstul@us.ibm.com> LKML-Reference: <1268968769-19209-1-git-send-email-johnstul@us.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | | sched: Intoduce get_cpu_iowait_time_us()Arjan van de Ven2010-05-092-0/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For the ondemand cpufreq governor, it is desired that the iowait time is microaccounted in a similar way as idle time is. This patch introduces the infrastructure to account and expose this information via the get_cpu_iowait_time_us() function. [akpm@linux-foundation.org: fix CONFIG_NO_HZ=n build] Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Rik van Riel <riel@redhat.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: davej@redhat.com LKML-Reference: <20100509082523.284feab6@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | sched: Eliminate the ts->idle_lastupdate fieldArjan van de Ven2010-05-091-4/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that the only user of ts->idle_lastupdate is update_ts_time_stats(), the entire field can be eliminated. In update_ts_time_stats(), idle_lastupdate is first set to "now", and a few lines later, the only user is an if() statement that assigns a variable either to "now" or to ts->idle_lastupdate, which has the value of "now" at that point. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Rik van Riel <riel@redhat.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: davej@redhat.com LKML-Reference: <20100509082439.2fab0b4f@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | sched: Fold updating of the last_update_time_info into update_ts_time_stats()Arjan van de Ven2010-05-091-11/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch folds the updating of the last_update_time into the update_ts_time_stats() function, and updates the callers. This allows for further cleanups that are done in the next patch. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Rik van Riel <riel@redhat.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: davej@redhat.com LKML-Reference: <20100509082403.60072967@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | sched: Update the idle statistics in get_cpu_idle_time_us()Arjan van de Ven2010-05-091-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Right now, get_cpu_idle_time_us() only reports the idle statistics upto the point the CPU entered last idle; not what is valid right now. This patch adds an update of the idle statistics to get_cpu_idle_time_us(), so that calling this function always returns statistics that are accurate at the point of the call. This includes resetting the start of the idle time for accounting purposes to avoid double accounting. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Rik van Riel <riel@redhat.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: davej@redhat.com LKML-Reference: <20100509082323.2d2f1945@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | sched: Introduce a function to update the idle statisticsArjan van de Ven2010-05-091-10/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, two places update the idle statistics (and more to come later in this series). This patch creates a helper function for updating these statistics. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Rik van Riel <riel@redhat.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: davej@redhat.com LKML-Reference: <20100509082245.163e67ed@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | sched: Add a comment to get_cpu_idle_time_us()Arjan van de Ven2010-05-091-0/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The exported function get_cpu_idle_time_us() has no comment describing it; add a kerneldoc comment Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Rik van Riel <riel@redhat.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: davej@redhat.com LKML-Reference: <20100509082208.7cb721f0@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | Merge branch 'linus' into sched/coreIngo Molnar2010-04-151-0/+1
|\ \ \ | | |/ | |/| | | | | | | | | | Merge reason: merge the latest fixes, update to -rc4. Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo2010-03-301-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
* | | Merge branch 'linus' into sched/coreIngo Molnar2010-04-024-14/+48
|\ \ \ | |/ / | | | | | | | | | | | | Merge reason: update to latest upstream Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | time: Fix accumulation bug triggered by long delay.John Stultz2010-03-231-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The logarithmic accumulation done in the timekeeping has some overflow protection that limits the max shift value. That means it will take more then shift loops to accumulate all of the cycles. This causes the shift decrement to underflow, which causes the loop to never exit. The simplest fix would be simply to do a: if (shift) shift--; However that is not optimal, as we know the cycle offset is larger then the interval << shift, the above would make shift drop to zero, then we would be spinning for quite awhile accumulating at interval chunks at a time. Instead, this patch only decreases shift if the offset is smaller then cycle_interval << shift. This makes sure we accumulate using the largest chunks possible without overflowing tick_length, and limits the number of iterations through the loop. This issue was found and reported by Sonic Zhang, who also tested the fix. Many thanks your explanation and testing! Reported-by: Sonic Zhang <sonic.adi@gmail.com> Signed-off-by: John Stultz <johnstul@us.ibm.com> Tested-by: Sonic Zhang <sonic.adi@gmail.com> LKML-Reference: <1268948850-5225-1-git-send-email-johnstul@us.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | clockevents: Sanitize min_delta_ns adjustment and prevent overflowsThomas Gleixner2010-03-122-13/+42
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | The current logic which handles clock events programming failures can increase min_delta_ns unlimited and even can cause overflows. Sanitize it by: - prevent zero increase when min_delta_ns == 1 - limiting min_delta_ns to a jiffie - bail out if the jiffie limit is hit - add retries stats for /proc/timer_list so we can gather data Reported-by: Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * timekeeping: Prevent oops when GENERIC_TIME=njohn stultz2010-03-021-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Aaro Koskinen reported an issue in kernel.org bugzilla #15366, where on non-GENERIC_TIME systems, accessing /sys/devices/system/clocksource/clocksource0/current_clocksource results in an oops. It seems the timekeeper/clocksource rework missed initializing the curr_clocksource value in the !GENERIC_TIME case. Thanks to Aaro for reporting and diagnosing the issue as well as testing the fix! Reported-by: Aaro Koskinen <aaro.koskinen@iki.fi> Signed-off-by: John Stultz <johnstul@us.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: stable@kernel.org LKML-Reference: <1267475683.4216.61.camel@localhost.localdomain> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | sched: Rate-limit nohzMike Galbraith2010-03-111-0/+3
|/ | | | | | | | | | | | | | | Entering nohz code on every micro-idle is costing ~10% throughput for netperf TCP_RR when scheduling cross-cpu. Rate limiting entry fixes this, but raises ticks a bit. On my Q6600, an idle box goes from ~85 interrupts/sec to 128. The higher the context switch rate, the more nohz entry costs. With this patch and some cycle recovery patches in my tree, max cross cpu context switch rate is improved by ~16%, a large portion of which of which is this ratelimiting. Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1268301003.6785.28.camel@marge.simson.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Merge branch 'timers-for-linus' of ↵Linus Torvalds2010-03-013-6/+19
|\ | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: posix-timers.c: Don't export local functions clocksource: start CMT at clocksource resume clocksource: add suspend callback clocksource: add argument to resume callback ntp: Cleanup xtime references in ntp.c ntp: Make time_esterror and time_maxerror static
| * clocksource: add suspend callbackMagnus Damm2010-02-052-0/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a clocksource suspend callback. This callback can be used by the clocksource driver to shutdown and perform any kind of late suspend activities even though the clocksource driver itself is a non-sysdev driver. One example where this is useful is to fix the sh_cmt.c platform driver that today suspends using the platform bus and shuts down the clocksource too early. With this callback in place the sh_cmt driver will suspend using the clocksource and clockevent hooks and leave the platform device pm callbacks unused. Signed-off-by: Magnus Damm <damm@opensource.se> Cc: Paul Mundt <lethal@linux-sh.org> Cc: john stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * clocksource: add argument to resume callbackMagnus Damm2010-02-051-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | Pass the clocksource as an argument to the clocksource resume callback. Needed so we can point out which CMT channel the sh_cmt.c driver shall resume. Signed-off-by: Magnus Damm <damm@opensource.se> Cc: john stultz <johnstul@us.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * ntp: Cleanup xtime references in ntp.cJohn Stultz2010-01-291-3/+3
| | | | | | | | | | | | | | | | | | | | ntp.c doesn't need to access timekeeping internals directly, so change xtime references to use the get_seconds() timekeeping interface. Signed-off-by: John Stultz <johnstul@us.ibm.com> Cc: richard@rsk.demon.co.uk LKML-Reference: <1264738844-21935-1-git-send-email-johnstul@us.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * ntp: Make time_esterror and time_maxerror staticjohn stultz2010-01-291-2/+2
| | | | | | | | | | | | | | | | | | | | | | Make time_esterror and time_maxerror static as no one uses them outside of ntp.c Signed-off-by: John Stultz <johnstul@us.ibm.com> Cc: richard@rsk.demon.co.uk LKML-Reference: <1264719761.3437.47.camel@localhost.localdomain> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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