linux/kernel/torture.c, branch v5.10

torture: Dump ftrace at shutdown only if requested

2020-06-29T19:01:45Z

If there is a large number of torture tests running concurrently, all of which are dumping large ftrace buffers at shutdown time, the resulting dumping can take a very long time, particularly on systems with rotating-rust storage. This commit therefore adds a default-off torture.ftrace_dump_at_shutdown module parameter that enables shutdown-time ftrace-buffer dumping. Signed-off-by: Paul E. McKenney

Merge tag 'smp-core-2020-03-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2020-03-31T01:06:39Z

Pull core SMP updates from Thomas Gleixner: "CPU (hotplug) updates: - Support for locked CSD objects in smp_call_function_single_async() which allows to simplify callsites in the scheduler core and MIPS - Treewide consolidation of CPU hotplug functions which ensures the consistency between the sysfs interface and kernel state. The low level functions cpu_up/down() are now confined to the core code and not longer accessible from random code" * tag 'smp-core-2020-03-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (22 commits) cpu/hotplug: Ignore pm_wakeup_pending() for disable_nonboot_cpus() cpu/hotplug: Hide cpu_up/down() cpu/hotplug: Move bringup of secondary CPUs out of smp_init() torture: Replace cpu_up/down() with add/remove_cpu() firmware: psci: Replace cpu_up/down() with add/remove_cpu() xen/cpuhotplug: Replace cpu_up/down() with device_online/offline() parisc: Replace cpu_up/down() with add/remove_cpu() sparc: Replace cpu_up/down() with add/remove_cpu() powerpc: Replace cpu_up/down() with add/remove_cpu() x86/smp: Replace cpu_up/down() with add/remove_cpu() arm64: hibernate: Use bringup_hibernate_cpu() cpu/hotplug: Provide bringup_hibernate_cpu() arm64: Use reboot_cpu instead of hardconding it to 0 arm64: Don't use disable_nonboot_cpus() ARM: Use reboot_cpu instead of hardcoding it to 0 ARM: Don't use disable_nonboot_cpus() ia64: Replace cpu_down() with smp_shutdown_nonboot_cpus() cpu/hotplug: Create a new function to shutdown nonboot cpus cpu/hotplug: Add new {add,remove}_cpu() functions sched/core: Remove rq.hrtick_csd_pending ...

torture: Replace cpu_up/down() with add/remove_cpu()

2020-03-25T11:59:37Z

The core device API performs extra housekeeping bits that are missing from directly calling cpu_up/down(). See commit a6717c01ddc2 ("powerpc/rtas: use device model APIs and serialization during LPM") for an example description of what might go wrong. This also prepares to make cpu_up/down() a private interface of the CPU subsystem. Signed-off-by: Qais Yousef Signed-off-by: Thomas Gleixner Acked-by: "Paul E. McKenney" Link: https://lkml.kernel.org/r/20200323135110.30522-16-qais.yousef@arm.com

torture: Allow disabling of boottime CPU-hotplug torture operations

2020-02-21T00:03:30Z

In theory, RCU-hotplug operations are supposed to work as soon as there is more than one CPU online. However, in practice, in normal production there is no way to make them happen until userspace is up and running. Besides which, on smaller systems, rcutorture doesn't start doing hotplug operations until 30 seconds after the start of boot, which on most systems also means the better part of 30 seconds after the end of boot. This commit therefore provides a new torture.disable_onoff_at_boot kernel boot parameter that suppresses CPU-hotplug torture operations until about the time that init is spawned. Of course, if you know of a need for boottime CPU-hotplug operations, then you should avoid passing this argument to any of the torture tests. You might also want to look at the splats linked to below. Link: https://lore.kernel.org/lkml/20191206185208.GA25636@paulmck-ThinkPad-P72/ Signed-off-by: Paul E. McKenney

torture: Forgive -EBUSY from boottime CPU-hotplug operations

2020-02-21T00:03:30Z

During boot, CPU hotplug is often disabled, for example by PCI probing. On large systems that take substantial time to boot, this can result in spurious RCU_HOTPLUG errors. This commit therefore forgives any boottime -EBUSY CPU-hotplug failures by adjusting counters to pretend that the corresponding attempt never happened. A non-splat record of the failed attempt is emitted to the console with the added string "(-EBUSY forgiven during boot)". Signed-off-by: Paul E. McKenney

torture: Remove exporting of internal functions

2019-08-01T21:30:22Z

The functions torture_onoff_cleanup() and torture_shuffle_cleanup() are declared static and marked EXPORT_SYMBOL_GPL(), which is at best an odd combination. Because these functions are not used outside of the kernel/torture.c file they are defined in, this commit removes their EXPORT_SYMBOL_GPL() marking. Fixes: cc47ae083026 ("rcutorture: Abstract torture-test cleanup") Signed-off-by: Denis Efremov Signed-off-by: Paul E. McKenney

torture: Allow inter-stutter interval to be specified

2019-05-28T16:06:09Z

Currently, the inter-stutter interval is the same as the stutter duration, that is, whatever number of jiffies is passed into torture_stutter_init(). This has worked well for quite some time, but the addition of forward-progress testing to rcutorture can delay processes for several seconds, which can triple the time that they are stuttered. This commit therefore adds a second argument to torture_stutter_init() that specifies the inter-stutter interval. While locktorture preserves the current behavior, rcutorture uses the RCU CPU stall warning interval to provide a wider inter-stutter interval. Signed-off-by: Paul E. McKenney

rcutorture: Fix stutter_wait() return value and freelist checks

2019-05-28T16:06:09Z

The stutter_wait() function is supposed to return true if it actually waits and false otherwise, but it instead unconditionally returns false. Which hides a bug in rcu_torture_writer() that fails to account for the fact that one of the rcu_tortures[] array elements will normally be referenced by rcu_torture_current, and thus not be on the freelist. This commit therefore corrects the stutter_wait() return value and adds a check for rcu_torture_current to rcu_torture_writer()'s check that things get freed after everything goes quiescent. In addition, this commit causes torture_stutter() to give a bit more than one second (instead of only one jiffy) warning of the end of the stutter interval. Finally, this commit disables long-delay readers and aggressive update-side forward-progress checks while forward-progress testing is in flight. Reported-by: Sebastian Andrzej Siewior Signed-off-by: Paul E. McKenney

torture: Don't try to offline the last CPU

2019-03-26T21:42:53Z

If there is only one online CPU, it doesn't make sense to try to offline it, as any such attempt is guaranteed to fail. This commit therefore check for this condition and refuses to attempt the nonsensical. Reported-by: Su Yue Signed-off-by: Paul E. McKenney Tested-By: Su Yue

Merge branches 'doc.2019.01.26a', 'fixes.2019.01.26a', 'sil.2019.01.26a', 'spdx.2019.02.09a', 'srcu.2019.01.26a' and 'torture.2019.01.26a' into HEAD

2019-02-09T16:47:52Z

doc.2019.01.26a: Documentation updates. fixes.2019.01.26a: Miscellaneous fixes. sil.2019.01.26a: Removal of a few more spin_is_locked() instances. spdx.2019.02.09a: Add SPDX identifiers to RCU files srcu.2019.01.26a: SRCU updates. torture.2019.01.26a: Torture-test updates.