user/sven/linux.git/kernel/softlockup.c, branch v2.6.22.3

Add suspend-related notifications for CPU hotplug

2007-05-09T19:30:56Z

Since nonboot CPUs are now disabled after tasks and devices have been frozen and the CPU hotplug infrastructure is used for this purpose, we need special CPU hotplug notifications that will help the CPU-hotplug-aware subsystems distinguish normal CPU hotplug events from CPU hotplug events related to a system-wide suspend or resume operation in progress. This patch introduces such notifications and causes them to be used during suspend and resume transitions. It also changes all of the CPU-hotplug-aware subsystems to take these notifications into consideration (for now they are handled in the same way as the corresponding "normal" ones). [oleg@tv-sign.ru: cleanups] Signed-off-by: Rafael J. Wysocki Cc: Gautham R Shenoy Cc: Pavel Machek Signed-off-by: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

add touch_all_softlockup_watchdogs()

2007-05-08T18:15:06Z

Add touch_all_softlockup_watchdogs() to allow the softlockup watchdog timers on all cpus to be updated. This is used to prevent sysrq-t from generating a spurious watchdog message when generating lots of output. Softlockup watchdogs use sched_clock() as its timebase, which is inherently per-cpu (at least, when it is measuring unstolen time). Because of this, it isn't possible for one CPU to directly update the other CPU's timers, but it is possible to tell the other CPUs to do update themselves appropriately. Signed-off-by: Jeremy Fitzhardinge Acked-by: Chris Lalancette Signed-off-by: Prarit Bhargava Cc: Rick Lindsley Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Ignore stolen time in the softlockup watchdog

2007-05-08T18:15:06Z

The softlockup watchdog is currently a nuisance in a virtual machine, since the whole system could have the CPU stolen from it for a long period of time. While it would be unlikely for a guest domain to be denied timer interrupts for over 10s, it could happen and any softlockup message would be completely spurious. Earlier I proposed that sched_clock() return time in unstolen nanoseconds, which is how Xen and VMI currently implement it. If the softlockup watchdog uses sched_clock() to measure time, it would automatically ignore stolen time, and therefore only report when the guest itself locked up. When running native, sched_clock() returns real-time nanoseconds, so the behaviour would be unchanged. Note that sched_clock() used this way is inherently per-cpu, so this patch makes sure that the per-processor watchdog thread initialized its own timestamp. Signed-off-by: Jeremy Fitzhardinge Cc: Ingo Molnar Cc: Thomas Gleixner Cc: john stultz Cc: Zachary Amsden Cc: James Morris Cc: Dan Hecht Cc: Paul Mackerras Cc: Martin Schwidefsky Cc: Prarit Bhargava Cc: Chris Lalancette Cc: Rick Lindsley Cc: Eric Dumazet Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

softlockup: s/99/MAX_RT_PRIO/

2007-05-08T18:14:59Z

Don't use hardcoded 99 value, use MAX_RT_PRIO. Signed-off-by: Oleg Nesterov Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] check return value of cpu_callback

2006-09-29T16:18:14Z

Spawing ksoftirqd, migration, or watchdog, and calling init_timers_cpu() may fail with small memory. If it happens in initcalls, kernel NULL pointer dereference happens later. This patch makes crash happen immediately in such cases. It seems a bit better than getting kernel NULL pointer dereference later. Cc: Ingo Molnar Signed-off-by: Akinobu Mita Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] cpu hotplug: replace devinit* with cpuinit* for cpu notifications

2006-07-31T20:28:39Z

Few of the callback functions and notifier blocks that are associated with cpu notifications incorrectly have __devinit and __devinitdata. They should be __cpuinit and __cpuinitdata instead. It makes no functional difference but wastes text area when CONFIG_HOTPLUG is enabled and CONFIG_HOTPLUG_CPU is not. This patch fixes all those instances. Signed-off-by: Chandra Seetharaman Cc: Ashok Raj Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] cpu hotplug: revert initdata patch submitted for 2.6.17

2006-06-28T00:32:41Z

This patch reverts notifier_block changes made in 2.6.17 Signed-off-by: Chandra Seetharaman Cc: Ashok Raj Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] cpu hotplug: revert init patch submitted for 2.6.17

2006-06-28T00:32:40Z

In 2.6.17, there was a problem with cpu_notifiers and XFS. I provided a band-aid solution to solve that problem. In the process, i undid all the changes you both were making to ensure that these notifiers were available only at init time (unless CONFIG_HOTPLUG_CPU is defined). We deferred the real fix to 2.6.18. Here is a set of patches that fixes the XFS problem cleanly and makes the cpu notifiers available only at init time (unless CONFIG_HOTPLUG_CPU is defined). If CONFIG_HOTPLUG_CPU is defined then cpu notifiers are available at run time. This patch reverts the notifier_call changes made in 2.6.17 Signed-off-by: Chandra Seetharaman Cc: Ashok Raj Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] cpu hotplug: fix CPU_UP_CANCEL handling

2006-06-25T17:01:22Z

If a cpu hotplug callback fails on CPU_UP_PREPARE, all callbacks will be called with CPU_UP_CANCELED. A few of these callbacks assume that on CPU_UP_PREPARE a pointer to task has been stored in a percpu array. This assumption is not true if CPU_UP_PREPARE fails and the following calls to kthread_bind() in CPU_UP_CANCELED will cause an addressing exception because of passing a NULL pointer. Signed-off-by: Heiko Carstens Cc: Ashok Raj Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] Define __raw_get_cpu_var and use it

2006-06-25T17:01:01Z

There are several instances of per_cpu(foo, raw_smp_processor_id()), which is semantically equivalent to __get_cpu_var(foo) but without the warning that smp_processor_id() can give if CONFIG_DEBUG_PREEMPT is enabled. For those architectures with optimized per-cpu implementations, namely ia64, powerpc, s390, sparc64 and x86_64, per_cpu() turns into more and slower code than __get_cpu_var(), so it would be preferable to use __get_cpu_var on those platforms. This defines a __raw_get_cpu_var(x) macro which turns into per_cpu(x, raw_smp_processor_id()) on architectures that use the generic per-cpu implementation, and turns into __get_cpu_var(x) on the architectures that have an optimized per-cpu implementation. Signed-off-by: Paul Mackerras Acked-by: David S. Miller Acked-by: Ingo Molnar Acked-by: Martin Schwidefsky Cc: Rusty Russell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds