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* kernel: Fix files explicitly needing EXPORT_SYMBOL infrastructurePaul Gortmaker2011-11-0110-0/+10
| | | | | | | | | | These files were getting <linux/module.h> via an implicit non-obvious path, but we want to crush those out of existence since they cost time during compiles of processing thousands of lines of headers for no reason. Give them the lightweight header that just contains the EXPORT_SYMBOL infrastructure. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* kernel: fix up module header handling in rcutiny filesPaul Gortmaker2011-10-312-1/+1
| | | | | | | | | | | The file rcutiny.c does not need moduleparam.h header, as there are no modparams in this file. However rcutiny_plugin.h does define a module_init() and a module_exit() and it uses the various MODULE_ macros, so it really does need module.h included. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* kernel: params.c needs module.h not moduleparam.hPaul Gortmaker2011-10-311-1/+1
| | | | | | | | | | | | | | Through various other implicit include paths, some files were getting the full module.h file, and hence living the illusion that they really only needed moduleparam.h -- but the reality is that once you remove the module.h presence, these show up: kernel/params.c:583: warning: ‘struct module_kobject’ declared inside parameter list Such files really require module.h so simply make it so. As the file module.h grabs moduleparam.h on the fly, all will be well. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* kernel: ksysfs.c is implicitly using stat.hPaul Gortmaker2011-10-311-0/+1
| | | | | | | | | With the module.h usage cleanup, we'll get this: kernel/ksysfs.c:161: error: ‘S_IRUGO’ undeclared here (not in a function) make[2]: *** [kernel/ksysfs.o] Error 1 Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* kernel: fix two implicit header assumptions in irq_work.cPaul Gortmaker2011-10-311-0/+2
| | | | | | | | | | | | | | | | | Up until now, this file was getting percpu.h because nearly every file was implicitly getting module.h (and all its sub-includes). But we want to clean that up, so call out percpu.h explicitly. Otherwise we'll get things like this on an ARM build: kernel/irq_work.c:48: error: expected declaration specifiers or '...' before 'irq_work_list' kernel/irq_work.c:48: warning: type defaults to 'int' in declaration of 'DEFINE_PER_CPU' The same thing was happening for builds on ARM for asm/processor.h kernel/irq_work.c: In function 'irq_work_sync': kernel/irq_work.c:166: error: implicit declaration of function 'cpu_relax' Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* kernel: fix several implicit usasges of kmod.hPaul Gortmaker2011-10-313-0/+3
| | | | | | | | | | | | | | | | | These files were implicitly relying on <linux/kmod.h> coming in via module.h, as without it we get things like: kernel/power/suspend.c:100: error: implicit declaration of function ‘usermodehelper_disable’ kernel/power/suspend.c:109: error: implicit declaration of function ‘usermodehelper_enable’ kernel/power/user.c:254: error: implicit declaration of function ‘usermodehelper_disable’ kernel/power/user.c:261: error: implicit declaration of function ‘usermodehelper_enable’ kernel/sys.c:317: error: implicit declaration of function ‘usermodehelper_disable’ kernel/sys.c:1816: error: implicit declaration of function ‘call_usermodehelper_setup’ kernel/sys.c:1822: error: implicit declaration of function ‘call_usermodehelper_setfns’ kernel/sys.c:1824: error: implicit declaration of function ‘call_usermodehelper_exec’ Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* kernel: Add <linux/module.h> to files using it implicitlyPaul Gortmaker2011-10-312-0/+2
| | | | | | | | | These files are doing things like module_put and try_module_get so they need to call out the module.h for explicit inclusion, rather than getting it via <linux/device.h> which we ideally want to remove the module.h inclusion from. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* kernel: Map most files to use export.h instead of module.hPaul Gortmaker2011-10-3161-61/+61
| | | | | | | | | | | | | | | | The changed files were only including linux/module.h for the EXPORT_SYMBOL infrastructure, and nothing else. Revector them onto the isolated export header for faster compile times. Nothing to see here but a whole lot of instances of: -#include <linux/module.h> +#include <linux/export.h> This commit is only changing the kernel dir; next targets will probably be mm, fs, the arch dirs, etc. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* range: fix bogus misuse of module.h to get printk()Paul Gortmaker2011-10-311-1/+1
| | | | | | | | This file isn't doing anything with modules and so it should not be including <linux/module.h> just to get basic stuff like printk() and min/max. Revector it to <linux/kernel.h>. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* Merge branch 'gpio/next' of git://git.secretlab.ca/git/linux-2.6Linus Torvalds2011-10-291-0/+4
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'gpio/next' of git://git.secretlab.ca/git/linux-2.6: h8300: Move gpio.h to gpio-internal.h gpio: pl061: add DT binding support gpio: fix build error in include/asm-generic/gpio.h gpiolib: Ensure struct gpio is always defined irq: Add EXPORT_SYMBOL_GPL to function of irq generic-chip gpio-ml-ioh: Use NUMA_NO_NODE not GFP_KERNEL gpio-pch: Use NUMA_NO_NODE not GFP_KERNEL gpio: langwell: ensure alternate function is cleared gpio-pch: Support interrupt function gpio-pch: Save register value in suspend() gpio-pch: modify gpio_nums and mask gpio-pch: support ML7223 IOH n-Bus gpio-pch: add spinlock in suspend/resume processing gpio-pch: Delete invalid "restore" code in suspend() gpio-ml-ioh: Fix suspend/resume issue gpio-ml-ioh: Support interrupt function gpio-ml-ioh: Delete unnecessary code gpio/mxc: add chained_irq_enter/exit() to mx3_gpio_irq_handler() gpio/nomadik: use genirq core to track enablement gpio/nomadik: disable clocks when unused
| * irq: Add EXPORT_SYMBOL_GPL to function of irq generic-chipNobuhiro Iwamatsu2011-10-241-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some functions of irq generic-chip is undefined, because EXPORT_SYMBOL_GPL is not set to these. ERROR: "irq_setup_generic_chip" [drivers/gpio/gpio-pch.ko] undefined! ERROR: "irq_alloc_generic_chip" [drivers/gpio/gpio-pch.ko] undefined! ERROR: "irq_setup_generic_chip" [drivers/gpio/gpio-ml-ioh.ko] undefined! ERROR: "irq_alloc_generic_chip" [drivers/gpio/gpio-ml-ioh.ko] undefined! This is revised that EXPORT_SYMBOL_GPL can be added and referred to in functions. Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
* | Merge branch 'devel-stable' of ↵Linus Torvalds2011-10-283-0/+238
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | http://ftp.arm.linux.org.uk/pub/linux/arm/kernel/git-cur/linux-2.6-arm * 'devel-stable' of http://ftp.arm.linux.org.uk/pub/linux/arm/kernel/git-cur/linux-2.6-arm: (178 commits) ARM: 7139/1: fix compilation with CONFIG_ARM_ATAG_DTB_COMPAT and large TEXT_OFFSET ARM: gic, local timers: use the request_percpu_irq() interface ARM: gic: consolidate PPI handling ARM: switch from NO_MACH_MEMORY_H to NEED_MACH_MEMORY_H ARM: mach-s5p64x0: remove mach/memory.h ARM: mach-s3c64xx: remove mach/memory.h ARM: plat-mxc: remove mach/memory.h ARM: mach-prima2: remove mach/memory.h ARM: mach-zynq: remove mach/memory.h ARM: mach-bcmring: remove mach/memory.h ARM: mach-davinci: remove mach/memory.h ARM: mach-pxa: remove mach/memory.h ARM: mach-ixp4xx: remove mach/memory.h ARM: mach-h720x: remove mach/memory.h ARM: mach-vt8500: remove mach/memory.h ARM: mach-s5pc100: remove mach/memory.h ARM: mach-tegra: remove mach/memory.h ARM: plat-tcc: remove mach/memory.h ARM: mach-mmp: remove mach/memory.h ARM: mach-cns3xxx: remove mach/memory.h ... Fix up mostly pretty trivial conflicts in: - arch/arm/Kconfig - arch/arm/include/asm/localtimer.h - arch/arm/kernel/Makefile - arch/arm/mach-shmobile/board-ap4evb.c - arch/arm/mach-u300/core.c - arch/arm/mm/dma-mapping.c - arch/arm/mm/proc-v7.S - arch/arm/plat-omap/Kconfig largely due to some CONFIG option renaming (ie CONFIG_PM_SLEEP -> CONFIG_ARM_CPU_SUSPEND for the arm-specific suspend code etc) and addition of NEED_MACH_MEMORY_H next to HAVE_IDE.
| * \ Merge branch 'ppi-irq-core-for-rmk' of ↵Russell King2011-10-235-23/+319
| |\ \ | | | | | | | | | | | | git://github.com/mzyngier/arm-platforms into devel-stable
| * \ \ Merge branch 'for_3_2/for-rmk/arm_cpu_pm' of ↵Russell King2011-09-263-0/+238
| |\ \ \ | | | | | | | | | | | | | | | git://gitorious.org/omap-sw-develoment/linux-omap-dev into devel-stable
| | * | | cpu_pm: call notifiers during suspendColin Cross2011-09-231-0/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implements syscore_ops in cpu_pm to call the cpu and cpu cluster notifiers during suspend and resume, allowing drivers receiving the notifications to avoid implementing syscore_ops. Signed-off-by: Colin Cross <ccross@android.com> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Reviewed-by: Kevin Hilman <khilman@ti.com> Tested-and-Acked-by: Shawn Guo <shawn.guo@linaro.org> Tested-by: Vishwanath BS <vishwanath.bs@ti.com>
| | * | | cpu_pm: Add cpu power management notifiersColin Cross2011-09-233-0/+205
| | | |/ | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | During some CPU power modes entered during idle, hotplug and suspend, peripherals located in the CPU power domain, such as the GIC, localtimers, and VFP, may be powered down. Add a notifier chain that allows drivers for those peripherals to be notified before and after they may be reset. Notified drivers can include VFP co-processor, interrupt controller and it's PM extensions, local CPU timers context save/restore which shouldn't be interrupted. Hence CPU PM event APIs must be called with interrupts disabled. Signed-off-by: Colin Cross <ccross@android.com> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Reviewed-by: Kevin Hilman <khilman@ti.com> Tested-and-Acked-by: Shawn Guo <shawn.guo@linaro.org> Tested-by: Kevin Hilman <khilman@ti.com> Tested-by: Vishwanath BS <vishwanath.bs@ti.com>
| * | | Merge branch 'kprobes-test' of git://git.yxit.co.uk/linux into devel-stableRussell King2011-09-213-33/+95
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| * | | perf: provide PMU when initing eventsMark Rutland2011-08-311-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, an event's 'pmu' field is set after pmu::event_init() is called. This means that pmu::event_init() must figure out which struct pmu the event was initialised from. This makes it difficult to consolidate common event initialisation code for similar PMUs, and very difficult to implement drivers for PMUs which can have multiple instances (e.g. a USB controller PMU, a GPU PMU, etc). This patch sets the 'pmu' field before initialising the event, allowing event init code to identify the struct pmu instance easily. In the event of failure to initialise an event, the event is destroyed via kfree() without calling perf_event::destroy(), so this shouldn't result in bad behaviour even if the destroy field was set before failure to initialise was noted. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1313062280-19123-1-git-send-email-mark.rutland@arm.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | | Merge branch 'timers-core-for-linus' of ↵Linus Torvalds2011-10-2610-214/+365
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits) time, s390: Get rid of compile warning dw_apb_timer: constify clocksource name time: Cleanup old CONFIG_GENERIC_TIME references that snuck in time: Change jiffies_to_clock_t() argument type to unsigned long alarmtimers: Fix error handling clocksource: Make watchdog reset lockless posix-cpu-timers: Cure SMP accounting oddities s390: Use direct ktime path for s390 clockevent device clockevents: Add direct ktime programming function clockevents: Make minimum delay adjustments configurable nohz: Remove "Switched to NOHz mode" debugging messages proc: Consider NO_HZ when printing idle and iowait times nohz: Make idle/iowait counter update conditional nohz: Fix update_ts_time_stat idle accounting cputime: Clean up cputime_to_usecs and usecs_to_cputime macros alarmtimers: Rework RTC device selection using class interface alarmtimers: Add try_to_cancel functionality alarmtimers: Add more refined alarm state tracking alarmtimers: Remove period from alarm structure alarmtimers: Remove interval cap limit hack ...
| * | | | time: Change jiffies_to_clock_t() argument type to unsigned longhank2011-09-211-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The parameter's origin type is long. On an i386 architecture, it can easily be larger than 0x80000000, causing this function to convert it to a sign-extended u64 type. Change the type to unsigned long so we get the correct result. Signed-off-by: hank <pyu@redhat.com> Cc: John Stultz <john.stultz@linaro.org> Cc: <stable@kernel.org> [ build fix ] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | alarmtimers: Fix error handlingThomas Gleixner2011-09-141-10/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 8bc0daf (alarmtimers: Rework RTC device selection using class interface) did not implement required error checks. Add them. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | clocksource: Make watchdog reset locklessThomas Gleixner2011-09-131-20/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | KGDB needs to trylock watchdog_lock when trying to reset the clocksource watchdog after the system has been stopped to avoid a potential deadlock. When the trylock fails TSC usually becomes unstable. We can be more clever by using an atomic counter and checking it in the clocksource_watchdog callback. We restart the watchdog whenever the counter is > 0 and only decrement the counter when we ran through a full update cycle. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <johnstul@us.ibm.com> Acked-by: Jason Wessel <jason.wessel@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1109121326280.2723@ionos Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | posix-cpu-timers: Cure SMP accounting odditiesPeter Zijlstra2011-09-082-26/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | David reported: Attached below is a watered-down version of rt/tst-cpuclock2.c from GLIBC. Just build it with "gcc -o test test.c -lpthread -lrt" or similar. Run it several times, and you will see cases where the main thread will measure a process clock difference before and after the nanosleep which is smaller than the cpu-burner thread's individual thread clock difference. This doesn't make any sense since the cpu-burner thread is part of the top-level process's thread group. I've reproduced this on both x86-64 and sparc64 (using both 32-bit and 64-bit binaries). For example: [davem@boricha build-x86_64-linux]$ ./test process: before(0.001221967) after(0.498624371) diff(497402404) thread: before(0.000081692) after(0.498316431) diff(498234739) self: before(0.001223521) after(0.001240219) diff(16698) [davem@boricha build-x86_64-linux]$ The diff of 'process' should always be >= the diff of 'thread'. I make sure to wrap the 'thread' clock measurements the most tightly around the nanosleep() call, and that the 'process' clock measurements are the outer-most ones. --- #include <unistd.h> #include <stdio.h> #include <stdlib.h> #include <time.h> #include <fcntl.h> #include <string.h> #include <errno.h> #include <pthread.h> static pthread_barrier_t barrier; static void *chew_cpu(void *arg) { pthread_barrier_wait(&barrier); while (1) __asm__ __volatile__("" : : : "memory"); return NULL; } int main(void) { clockid_t process_clock, my_thread_clock, th_clock; struct timespec process_before, process_after; struct timespec me_before, me_after; struct timespec th_before, th_after; struct timespec sleeptime; unsigned long diff; pthread_t th; int err; err = clock_getcpuclockid(0, &process_clock); if (err) return 1; err = pthread_getcpuclockid(pthread_self(), &my_thread_clock); if (err) return 1; pthread_barrier_init(&barrier, NULL, 2); err = pthread_create(&th, NULL, chew_cpu, NULL); if (err) return 1; err = pthread_getcpuclockid(th, &th_clock); if (err) return 1; pthread_barrier_wait(&barrier); err = clock_gettime(process_clock, &process_before); if (err) return 1; err = clock_gettime(my_thread_clock, &me_before); if (err) return 1; err = clock_gettime(th_clock, &th_before); if (err) return 1; sleeptime.tv_sec = 0; sleeptime.tv_nsec = 500000000; nanosleep(&sleeptime, NULL); err = clock_gettime(th_clock, &th_after); if (err) return 1; err = clock_gettime(my_thread_clock, &me_after); if (err) return 1; err = clock_gettime(process_clock, &process_after); if (err) return 1; diff = process_after.tv_nsec - process_before.tv_nsec; printf("process: before(%lu.%.9lu) after(%lu.%.9lu) diff(%lu)\n", process_before.tv_sec, process_before.tv_nsec, process_after.tv_sec, process_after.tv_nsec, diff); diff = th_after.tv_nsec - th_before.tv_nsec; printf("thread: before(%lu.%.9lu) after(%lu.%.9lu) diff(%lu)\n", th_before.tv_sec, th_before.tv_nsec, th_after.tv_sec, th_after.tv_nsec, diff); diff = me_after.tv_nsec - me_before.tv_nsec; printf("self: before(%lu.%.9lu) after(%lu.%.9lu) diff(%lu)\n", me_before.tv_sec, me_before.tv_nsec, me_after.tv_sec, me_after.tv_nsec, diff); return 0; } This is due to us using p->se.sum_exec_runtime in thread_group_cputime() where we iterate the thread group and sum all data. This does not take time since the last schedule operation (tick or otherwise) into account. We can cure this by using task_sched_runtime() at the cost of having to take locks. This also means we can (and must) do away with thread_group_sched_runtime() since the modified thread_group_cputime() is now more accurate and would deadlock when called from thread_group_sched_runtime(). Reported-by: David Miller <davem@davemloft.net> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1314874459.7945.22.camel@twins Cc: stable@kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | clockevents: Add direct ktime programming functionMartin Schwidefsky2011-09-081-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is at least one architecture (s390) with a sane clockevent device that can be programmed with the equivalent of a ktime. No need to create a delta against the current time, the ktime can be used directly. A new clock device function 'set_next_ktime' is introduced that is called with the unmodified ktime for the timer if the clock event device has the CLOCK_EVT_FEAT_KTIME bit set. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: john stultz <johnstul@us.ibm.com> Link: http://lkml.kernel.org/r/20110823133142.815350967@de.ibm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | clockevents: Make minimum delay adjustments configurableMartin Schwidefsky2011-09-086-93/+121
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The automatic increase of the min_delta_ns of a clockevents device should be done in the clockevents code as the minimum delay is an attribute of the clockevents device. In addition not all architectures want the automatic adjustment, on a massively virtualized system it can happen that the programming of a clock event fails several times in a row because the virtual cpu has been rescheduled quickly enough. In that case the minimum delay will erroneously be increased with no way back. The new config symbol GENERIC_CLOCKEVENTS_MIN_ADJUST is used to enable the automatic adjustment. The config option is selected only for x86. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: john stultz <johnstul@us.ibm.com> Link: http://lkml.kernel.org/r/20110823133142.494157493@de.ibm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | nohz: Remove "Switched to NOHz mode" debugging messagesHeiko Carstens2011-09-081-5/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When performing cpu hotplug tests the kernel printk log buffer gets flooded with pointless "Switched to NOHz mode..." messages. Especially when afterwards analyzing a dump this might have removed more interesting stuff out of the buffer. Assuming that switching to NOHz mode simply works just remove the printk. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Link: http://lkml.kernel.org/r/20110823112046.GB2540@osiris.boeblingen.de.ibm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | nohz: Make idle/iowait counter update conditionalMichal Hocko2011-09-081-6/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | get_cpu_{idle,iowait}_time_us update idle/iowait counters unconditionally if the given CPU is in the idle loop. This doesn't work well outside of CPU governors which are singletons so nobody (except for IRQ) can race with them. We will need to use both functions from /proc/stat handler to properly handle nohz idle/iowait times. Make the update depend on a non NULL last_update_time argument. Signed-off-by: Michal Hocko <mhocko@suse.cz> Cc: Dave Jones <davej@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Alexey Dobriyan <adobriyan@gmail.com> Link: http://lkml.kernel.org/r/11f23179472635ce52e78921d47a20216b872f23.1314172057.git.mhocko@suse.cz Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | nohz: Fix update_ts_time_stat idle accountingMichal Hocko2011-09-081-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | update_ts_time_stat currently updates idle time even if we are in iowait loop at the moment. The only real users of the idle counter (via get_cpu_idle_time_us) are CPU governors and they expect to get cumulative time for both idle and iowait times. The value (idle_sleeptime) is also printed to userspace by print_cpu but it prints both idle and iowait times so the idle part is misleading. Let's clean this up and fix update_ts_time_stat to account both counters properly and update consumers of idle to consider iowait time as well. If we do this we might use get_cpu_{idle,iowait}_time_us from other contexts as well and we will get expected values. Signed-off-by: Michal Hocko <mhocko@suse.cz> Cc: Dave Jones <davej@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Alexey Dobriyan <adobriyan@gmail.com> Link: http://lkml.kernel.org/r/e9c909c221a8da402c4da07e4cd968c3218f8eb1.1314172057.git.mhocko@suse.cz Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | alarmtimers: Rework RTC device selection using class interfaceJohn Stultz2011-08-101-38/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This allows cleaner detection of the RTC device being registered, rather then probing any time someone calls alarmtimer_get_rtcdev. CC: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
| * | | | alarmtimers: Add try_to_cancel functionalityJohn Stultz2011-08-101-6/+37
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There's a number of edge cases when cancelling a alarm, so to be sure we accurately do so, introduce try_to_cancel, which returns proper failure errors if it cannot. Also modify cancel to spin until the alarm is properly disabled. CC: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
| * | | | alarmtimers: Add more refined alarm state trackingJohn Stultz2011-08-101-7/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to allow for functionality like try_to_cancel, add more refined state tracking (similar to hrtimers). CC: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
| * | | | alarmtimers: Remove period from alarm structureJohn Stultz2011-08-101-16/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that periodic alarmtimers are managed by the handler function, remove the period value from the alarm structure and let the handlers manage the interval on their own. CC: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
| * | | | alarmtimers: Remove interval cap limit hackJohn Stultz2011-08-101-9/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that the alarmtimers code has been refactored, the interval cap limit can be removed. CC: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
| * | | | alarmtimers: Add alarm_forward functionalityJohn Stultz2011-08-101-1/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to avoid wasting time expiring and re-adding very high freq periodic alarmtimers, introduce alarm_forward() which is similar to hrtimer_forward and moves the timer to the next future expiration time and returns the number of overruns. CC: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
| * | | | alarmtimers: Push rearming peroidic timers down into alamrtimer handlerJohn Stultz2011-08-101-7/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch pushes the periodic alarmtimer re-arming down into the alarmtimer handler, mimicking how hrtimers handle this. CC: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
| * | | | alarmtimers: Change alarmtimer functions to return alarmtimer_restart valuesJohn Stultz2011-08-101-4/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to properly fix the denial of service issue with high freq periodic alarm timers, we need to push the re-arming logic into the alarm timer handler, much as the hrtimer code does. This patch introduces alarmtimer_restart enum and changes the alarmtimer handler declarations to use it as a return value. Further, to ease following changes, it extends the alarmtimer handler functions to also take the time at expiration. No logic is yet modified. CC: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
* | | | | Merge branch 'sched-core-for-linus' of ↵Linus Torvalds2011-10-269-326/+1404
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (46 commits) llist: Add back llist_add_batch() and llist_del_first() prototypes sched: Don't use tasklist_lock for debug prints sched: Warn on rt throttling sched: Unify the ->cpus_allowed mask copy sched: Wrap scheduler p->cpus_allowed access sched: Request for idle balance during nohz idle load balance sched: Use resched IPI to kick off the nohz idle balance sched: Fix idle_cpu() llist: Remove cpu_relax() usage in cmpxchg loops sched: Convert to struct llist llist: Add llist_next() irq_work: Use llist in the struct irq_work logic llist: Return whether list is empty before adding in llist_add() llist: Move cpu_relax() to after the cmpxchg() llist: Remove the platform-dependent NMI checks llist: Make some llist functions inline sched, tracing: Show PREEMPT_ACTIVE state in trace_sched_switch sched: Remove redundant test in check_preempt_tick() sched: Add documentation for bandwidth control sched: Return unused runtime on group dequeue ...
| * | | | | sched: Don't use tasklist_lock for debug printsThomas Gleixner2011-10-061-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Avoid taking locks from debug prints, this avoids latencies on -rt, and improves reliability of the debug code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | sched: Warn on rt throttlingThomas Gleixner2011-10-061-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The default rt-throttling is a source of never ending questions. Warn once when we go into throttling so folks have that info in dmesg. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1110051331480.18778@ionos Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | sched: Unify the ->cpus_allowed mask copyPeter Zijlstra2011-10-062-7/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently every sched_class::set_cpus_allowed() implementation has to copy the cpumask into task_struct::cpus_allowed, this is pointless, put this copy in the generic code. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/n/tip-jhl5s9fckd9ptw1fzbqqlrd3@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | sched: Wrap scheduler p->cpus_allowed accessPeter Zijlstra2011-10-063-12/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This task is preparatory for the migrate_disable() implementation, but stands on its own and provides a cleanup. It currently only converts those sites required for task-placement. Kosaki-san once mentioned replacing cpus_allowed with a proper cpumask_t instead of the NR_CPUS sized array it currently is, that would also require something like this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Link: http://lkml.kernel.org/n/tip-e42skvaddos99psip0vce41o@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | sched: Request for idle balance during nohz idle load balanceSuresh Siddha2011-10-062-5/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | rq's idle_at_tick is set to idle/busy during the timer tick depending on the cpu was idle or not. This will be used later in the load balance that will be done in the softirq context (which is a process context in -RT kernels). For nohz kernels, for the cpu doing nohz idle load balance on behalf of all the idle cpu's, its rq->idle_at_tick might have a stale value (which is recorded when it got the timer tick presumably when it is busy). As the nohz idle load balancing is also being done at the same place as the regular load balancing, nohz idle load balancing was bailing out when it sees rq's idle_at_tick not set. Thus leading to poor system utilization. Rename rq's idle_at_tick to idle_balance and set it when someone requests for nohz idle balance on an idle cpu. Reported-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20111003220934.892350549@sbsiddha-desk.sc.intel.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | sched: Use resched IPI to kick off the nohz idle balanceSuresh Siddha2011-10-062-22/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Current use of smp call function to kick the nohz idle balance can deadlock in this scenario. 1. cpu-A did a generic_exec_single() to cpu-B and after queuing its call single data (csd) to the call single queue, cpu-A took a timer interrupt. Actual IPI to cpu-B to process the call single queue is not yet sent. 2. As part of the timer interrupt handler, cpu-A decided to kick cpu-B for the idle load balancing (sets cpu-B's rq->nohz_balance_kick to 1) and __smp_call_function_single() with nowait will queue the csd to the cpu-B's queue. But the generic_exec_single() won't send an IPI to cpu-B as the call single queue was not empty. 3. cpu-A is busy with lot of interrupts 4. Meanwhile cpu-B is entering and exiting idle and noticed that it has it's rq->nohz_balance_kick set to '1'. So it will go ahead and do the idle load balancer and clear its rq->nohz_balance_kick. 5. At this point, csd queued as part of the step-2 above is still locked and waiting to be serviced on cpu-B. 6. cpu-A is still busy with interrupt load and now it got another timer interrupt and as part of it decided to kick cpu-B for another idle load balancing (as it finds cpu-B's rq->nohz_balance_kick cleared in step-4 above) and does __smp_call_function_single() with the same csd that is still locked. 7. And we get a deadlock waiting for the csd_lock() in the __smp_call_function_single(). Main issue here is that cpu-B can service the idle load balancer kick request from cpu-A even with out receiving the IPI and this lead to doing multiple __smp_call_function_single() on the same csd leading to deadlock. To kick a cpu, scheduler already has the reschedule vector reserved. Use that mechanism (kick_process()) instead of using the generic smp call function mechanism to kick off the nohz idle load balancing and avoid the deadlock. [ This issue is present from 2.6.35+ kernels, but marking it -stable only from v3.0+ as the proposed fix depends on the scheduler_ipi() that is introduced recently. ] Reported-by: Prarit Bhargava <prarit@redhat.com> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: stable@kernel.org # v3.0+ Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20111003220934.834943260@sbsiddha-desk.sc.intel.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | sched: Fix idle_cpu()Thomas Gleixner2011-10-041-1/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On -rt we observed hackbench waking all 400 tasks to a single cpu. This is because of select_idle_sibling()'s interaction with the new ipi based wakeup scheme. The existing idle_cpu() test only checks to see if the current task on that cpu is the idle task, it does not take already queued tasks into account, nor does it take queued to be woken tasks into account. If the remote wakeup IPIs come hard enough, there won't be time to schedule away from the idle task, and would thus keep thinking the cpu was in fact idle, regardless of the fact that there were already several hundred tasks runnable. We couldn't reproduce on mainline, but there's no reason it couldn't happen. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/n/tip-3o30p18b2paswpc9ohy2gltp@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | sched: Convert to struct llistPeter Zijlstra2011-10-041-38/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use the generic llist primitives. We had a private lockless list implementation in the scheduler in the wake-list code, now that we have a generic llist implementation that provides all required operations, switch to it. This patch is not expected to change any behavior. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Huang Ying <ying.huang@intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/1315836353.26517.42.camel@twins Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | llist: Add llist_next()Peter Zijlstra2011-10-041-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | So we don't have to expose the struct list_node member. Cc: Huang Ying <ying.huang@intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1315836348.26517.41.camel@twins Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | irq_work: Use llist in the struct irq_work logicHuang Ying2011-10-041-58/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use llist in irq_work instead of the lock-less linked list implementation in irq_work to avoid the code duplication. Signed-off-by: Huang Ying <ying.huang@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1315461646-1379-6-git-send-email-ying.huang@intel.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | Merge branch 'linus' into sched/coreIngo Molnar2011-10-0410-53/+43
| |\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge reason: pick up the latest fixes. Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | sched: Remove redundant test in check_preempt_tick()Wang Xingchao2011-09-261-8/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The caller already checks for nr_running > 1, therefore we don't have to do so again. Signed-off-by: Wang Xingchao <xingchao.wang@intel.com> Reviewed-by: Paul Turner <pjt@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1316194552-12019-1-git-send-email-xingchao.wang@intel.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | Merge branch 'linus' into sched/coreIngo Molnar2011-09-1814-61/+203
| |\ \ \ \ \ \ | | | |_|_|/ / | | |/| | | | | | | | | | | | | | | | | | | | | | | | | Merge reason: We are queueing up a dependent patch. Signed-off-by: Ingo Molnar <mingo@elte.hu>