linux/kernel/torture.c, branch v5.19

torture: Wake up kthreads after storing task_struct pointer

2022-02-02T01:24:39Z

Currently, _torture_create_kthread() uses kthread_run() to create torture-test kthreads, which means that the resulting task_struct pointer is stored after the newly created kthread has been marked runnable. This in turn can cause spurious failure of checks for code being run by a particular kthread. This commit therefore changes _torture_create_kthread() to use kthread_create(), then to do an explicit wake_up_process() after the task_struct pointer has been stored. Reported-by: Frederic Weisbecker Reviewed-by: Neeraj Upadhyay Reviewed-by: Uladzislau Rezki (Sony) Reviewed-by: Frederic Weisbecker Signed-off-by: Paul E. McKenney

torture: Distinguish kthread stopping and being asked to stop

2022-02-02T01:24:38Z

Right now, if a given kthread (call it "kthread") realizes that it needs to stop, "Stopping kthread" is written to the console. When the cleanup code decides that it is time to stop that kthread, "Stopping kthread tasks" is written to the console. These two events might happen in either order, especially in the case of time-based torture-test shutdown. But it is hard to distinguish these, especially for those unfamiliar with the torture tests. This commit therefore changes the first case from "Stopping kthread" to "kthread is stopping" to make things more clear. Signed-off-by: Paul E. McKenney

locktorture,rcutorture,torture: Always log error message

2021-12-08T00:36:17Z

Unconditionally log messages corresponding to errors. Acked-by: Davidlohr Bueso Signed-off-by: Li Zhijian Signed-off-by: Paul E. McKenney

torture: Replace deprecated CPU-hotplug functions.

2021-08-10T17:48:07Z

The functions get_online_cpus() and put_online_cpus() have been deprecated during the CPU hotplug rework. They map directly to cpus_read_lock() and cpus_read_unlock(). Replace deprecated CPU-hotplug functions with the official version. The behavior remains unchanged. Cc: Davidlohr Bueso Cc: "Paul E. McKenney" Cc: Josh Triplett Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Paul E. McKenney

torture: Replace torture_init_begin string with %s

2021-03-08T22:22:28Z

This commit replaces a hard-coded "torture_init_begin" string in a pr_alert() format with "%s" and __func__. Signed-off-by: Stephen Zhang Signed-off-by: Paul E. McKenney

torture: Maintain torture-specific set of CPUs-online books

2021-01-07T01:17:22Z

The TREE01 rcutorture scenario intentionally creates confusion as to the number of available CPUs by specifying the "maxcpus=8 nr_cpus=43" kernel boot parameters. This can disable rcutorture's load shedding, which currently uses num_online_cpus(), which would count the extra 35 CPUs. However, the rcutorture guest OS will be provisioned with only 8 CPUs, which means that rcutorture will present full load even when all but one of the original 8 CPUs are offline. This can result in spurious errors due to extreme overloading of that single remaining CPU. This commit therefore keeps a separate set of books on the number of usable online CPUs, so that torture_num_online_cpus() is used for load shedding instead of num_online_cpus(). Note that initial sizing must use num_online_cpus() because torture_num_online_cpus() will return NR_CPUS until shortly after torture_onoff_init() is invoked. Reported-by: Frederic Weisbecker [ paulmck: Apply feedback from kernel test robot. ] Signed-off-by: Paul E. McKenney

torture: Clean up after torture-test CPU hotplugging

2021-01-07T01:17:22Z

This commit puts all CPUs back online at the end of a torture test, and also unconditionally puts them online at the beginning of the test, rather than just in the case of built-in tests. This allows torture tests to behave in a predictable manner, whether built-in or based on modules. Signed-off-by: Paul E. McKenney

torture: Throttle VERBOSE_TOROUT_*() output

2021-01-07T01:17:21Z

This commit adds kernel boot parameters torture.verbose_sleep_frequency and torture.verbose_sleep_duration, which allow VERBOSE_TOROUT_*() output to be throttled with periodic sleeps on large systems. Signed-off-by: Paul E. McKenney

torture: Make stutter use torture_hrtimeout_*() functions

2021-01-07T01:17:20Z

This commit saves a few lines of code by making the stutter_wait() and torture_stutter() functions use torture_hrtimeout_jiffies() and torture_hrtimeout_us(). Signed-off-by: Paul E. McKenney

torture: Add fuzzed hrtimer-based sleep functions

2021-01-07T01:17:19Z

This commit adds torture_hrtimeout_ns(), torture_hrtimeout_us(), torture_hrtimeout_ms(), torture_hrtimeout_jiffies(), and torture_hrtimeout_s(), each of which uses hrtimers to block for a fuzzed time interval. These functions are intended to be used by the various torture tests to decouple wakeups from the timer wheel, thus providing more opportunity for Murphy to insert destructive race conditions. Signed-off-by: Paul E. McKenney