user/sven/linux.git/include/linux/kernel_stat.h, branch v4.9.147

xen: add steal_clock support on x86

2016-07-06T09:34:48Z

The pv_time_ops structure contains a function pointer for the "steal_clock" functionality used only by KVM and Xen on ARM. Xen on x86 uses its own mechanism to account for the "stolen" time a thread wasn't able to run due to hypervisor scheduling. Add support in Xen arch independent time handling for this feature by moving it out of the arm arch into drivers/xen and remove the x86 Xen hack. Signed-off-by: Juergen Gross Reviewed-by: Boris Ostrovsky Reviewed-by: Stefano Stabellini Signed-off-by: David Vrabel

genirq: Prevent proc race against freeing of irq descriptors

2014-12-13T12:33:07Z

Since the rework of the sparse interrupt code to actually free the unused interrupt descriptors there exists a race between the /proc interfaces to the irq subsystem and the code which frees the interrupt descriptor. CPU0 CPU1 show_interrupts() desc = irq_to_desc(X); free_desc(desc) remove_from_radix_tree(); kfree(desc); raw_spinlock_irq(&desc->lock); /proc/interrupts is the only interface which can actively corrupt kernel memory via the lock access. /proc/stat can only read from freed memory. Extremly hard to trigger, but possible. The interfaces in /proc/irq/N/ are not affected by this because the removal of the proc file is serialized in procfs against concurrent readers/writers. The removal happens before the descriptor is freed. For architectures which have CONFIG_SPARSE_IRQ=n this is a non issue as the descriptor is never freed. It's merely cleared out with the irq descriptor lock held. So any concurrent proc access will either see the old correct value or the cleared out ones. Protect the lookup and access to the irq descriptor in show_interrupts() with the sparse_irq_lock. Provide kstat_irqs_usr() which is protecting the lookup and access with sparse_irq_lock and switch /proc/stat to use it. Document the existing kstat_irqs interfaces so it's clear that the caller needs to take care about protection. The users of these interfaces are either not affected due to SPARSE_IRQ=n or already protected against removal. Fixes: 1f5a5b87f78f "genirq: Implement a sane sparse_irq allocator" Signed-off-by: Thomas Gleixner Cc: stable@vger.kernel.org

sched/cputime: Fix cpu_timer_sample_group() double accounting

2014-11-16T09:04:18Z

While looking over the cpu-timer code I found that we appear to add the delta for the calling task twice, through: cpu_timer_sample_group() thread_group_cputimer() thread_group_cputime() times->sum_exec_runtime += task_sched_runtime(); *sample = cputime.sum_exec_runtime + task_delta_exec(); Which would make the sample run ahead, making the sleep short. Signed-off-by: Peter Zijlstra (Intel) Cc: KOSAKI Motohiro Cc: Oleg Nesterov Cc: Stanislaw Gruszka Cc: Christoph Lameter Cc: Frederic Weisbecker Cc: Linus Torvalds Cc: Rik van Riel Cc: Tejun Heo Link: http://lkml.kernel.org/r/20141112113737.GI10476@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar

scheduler: Replace __get_cpu_var with this_cpu_ptr

2014-08-26T17:45:45Z

Convert all uses of __get_cpu_var for address calculation to use this_cpu_ptr instead. [Uses of __get_cpu_var with cpumask_var_t are no longer handled by this patch] Cc: Peter Zijlstra Acked-by: Ingo Molnar Signed-off-by: Christoph Lameter Signed-off-by: Tejun Heo

Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2014-04-01T18:22:57Z

Pull irq code updates from Thomas Gleixner: "The irq department proudly presents: - Another tree wide sweep of irq infrastructure abuse. Clear winner of the trainwreck engineering contest was: #include "../../../kernel/irq/settings.h" - Tree wide update of irq_set_affinity() callbacks which miss a cpu online check when picking a single cpu out of the affinity mask. - Tree wide consolidation of interrupt statistics. - Updates to the threaded interrupt infrastructure to allow explicit wakeup of the interrupt thread and a variant of synchronize_irq() which synchronizes only the hard interrupt handler. Both are needed to replace the homebrewn thread handling in the mmc/sdhci code. - New irq chip callbacks to allow proper support for GPIO based irqs. The GPIO based interrupts need to request/release GPIO resources from request/free_irq. - A few new ARM interrupt chips. No revolutionary new hardware, just differently wreckaged variations of the scheme. - Small improvments, cleanups and updates all over the place" I was hoping that that trainwreck engineering contest was a April Fools' joke. But no. * 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (68 commits) irqchip: sun7i/sun6i: Disable NMI before registering the handler ARM: sun7i/sun6i: dts: Fix IRQ number for sun6i NMI controller ARM: sun7i/sun6i: irqchip: Update the documentation ARM: sun7i/sun6i: dts: Add NMI irqchip support ARM: sun7i/sun6i: irqchip: Add irqchip driver for NMI controller genirq: Export symbol no_action() arm: omap: Fix typo in ams-delta-fiq.c m68k: atari: Fix the last kernel_stat.h fallout irqchip: sun4i: Simplify sun4i_irq_ack irqchip: sun4i: Use handle_fasteoi_irq for all interrupts genirq: procfs: Make smp_affinity values go+r softirq: Add linux/irq.h to make it compile again m68k: amiga: Add linux/irq.h to make it compile again irqchip: sun4i: Don't ack IRQs > 0, fix acking of IRQ 0 irqchip: sun4i: Fix a comment about mask register initialization irqchip: sun4i: Fix irq 0 not working genirq: Add a new IRQCHIP_EOI_THREADED flag genirq: Document IRQCHIP_ONESHOT_SAFE flag ARM: sunxi: dt: Convert to the new irq controller compatibles irqchip: sunxi: Change compatibles ...

cputime: Default implementation of nsecs -> cputime conversion

2014-03-13T14:56:43Z

The architectures that override cputime_t (s390, ppc) don't provide any version of nsecs_to_cputime(). Indeed this cputime_t implementation by backend only happens when CONFIG_VIRT_CPU_ACCOUNTING_NATIVE=y under which the core code doesn't make any use of nsecs_to_cputime(). At least for now. We are going to make a broader use of it so lets provide a default version with a per usecs granularity. It should be good enough for most usecases. Cc: Ingo Molnar Cc: Marcelo Tosatti Cc: Peter Zijlstra Cc: Thomas Gleixner Acked-by: Rik van Riel Signed-off-by: Frederic Weisbecker

genirq: Move kstat_incr_irqs_this_cpu() to core

2014-03-04T16:37:54Z

No more users outside the core code. Put it into the poison cabinet. That also gets rid of the linux/irq.h include in kernel_stat.h Signed-off-by: Thomas Gleixner Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20140223212739.124207133@linutronix.de Signed-off-by: Thomas Gleixner

genirq: Add a kstat helper to increment irq stats

2014-03-04T16:37:53Z

There is a common pattern all over the place: kstat_incr_irqs_this_cpu(irq, irq_to_desc(irq)); This results in a call to core code anyway. So provide a function which does the same thing in core. While at it, replace the butt ugly macro with an inline. Signed-off-by: Thomas Gleixner Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20140223212737.422068876@linutronix.de Signed-off-by: Thomas Gleixner

Remove GENERIC_HARDIRQ config option

2013-09-13T13:09:52Z

After the last architecture switched to generic hard irqs the config options HAVE_GENERIC_HARDIRQS & GENERIC_HARDIRQS and the related code for !CONFIG_GENERIC_HARDIRQS can be removed. Signed-off-by: Martin Schwidefsky

cputime: Generic on-demand virtual cputime accounting

2013-01-27T18:23:27Z

If we want to stop the tick further idle, we need to be able to account the cputime without using the tick. Virtual based cputime accounting solves that problem by hooking into kernel/user boundaries. However implementing CONFIG_VIRT_CPU_ACCOUNTING require low level hooks and involves more overhead. But we already have a generic context tracking subsystem that is required for RCU needs by archs which plan to shut down the tick outside idle. This patch implements a generic virtual based cputime accounting that relies on these generic kernel/user hooks. There are some upsides of doing this: - This requires no arch code to implement CONFIG_VIRT_CPU_ACCOUNTING if context tracking is already built (already necessary for RCU in full tickless mode). - We can rely on the generic context tracking subsystem to dynamically (de)activate the hooks, so that we can switch anytime between virtual and tick based accounting. This way we don't have the overhead of the virtual accounting when the tick is running periodically. And one downside: - There is probably more overhead than a native virtual based cputime accounting. But this relies on hooks that are already set anyway. Signed-off-by: Frederic Weisbecker Cc: Andrew Morton Cc: Ingo Molnar Cc: Li Zhong Cc: Namhyung Kim Cc: Paul E. McKenney Cc: Paul Gortmaker Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Thomas Gleixner