user/sven/linux.git/include/linux/torture.h, branch v5.9.8

rcutorture: Add races with task-exit processing

2020-06-29T19:01:44Z

Several variants of Linux-kernel RCU interact with task-exit processing, including preemptible RCU, Tasks RCU, and Tasks Trace RCU. This commit therefore adds testing of this interaction to rcutorture by adding rcutorture.read_exit_burst and rcutorture.read_exit_delay kernel-boot parameters. These kernel parameters control the frequency and spacing of special read-then-exit kthreads that are spawned. [ paulmck: Apply feedback from Dan Carpenter's static checker. ] [ paulmck: Reduce latency to avoid false-positive shutdown hangs. ] Signed-off-by: Paul E. McKenney

locktorture.c: Fix if-statement empty body warnings

2020-04-27T18:05:13Z

When using -Wextra, gcc complains about torture_preempt_schedule() when its definition is empty (i.e., when CONFIG_PREEMPTION is not set/enabled). Fix these warnings by adding an empty do-while block for that macro when CONFIG_PREEMPTION is not set. Fixes these build warnings: ../kernel/locking/locktorture.c:119:29: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body] ../kernel/locking/locktorture.c:166:29: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body] ../kernel/locking/locktorture.c:337:29: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body] ../kernel/locking/locktorture.c:490:29: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body] ../kernel/locking/locktorture.c:528:29: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body] ../kernel/locking/locktorture.c:553:29: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body] I have verified that there is no object code change (with gcc 7.5.0). Signed-off-by: Randy Dunlap Cc: Davidlohr Bueso Cc: Josh Triplett Signed-off-by: "Paul E. McKenney"

rcu: Use CONFIG_PREEMPTION

2019-07-31T17:03:35Z

CONFIG_PREEMPTION is selected by CONFIG_PREEMPT and by CONFIG_PREEMPT_RT. Both PREEMPT and PREEMPT_RT require the same functionality which today depends on CONFIG_PREEMPT. Switch the conditionals in RCU to use CONFIG_PREEMPTION. That's the first step towards RCU on RT. The further tweaks are work in progress. This neither touches the selftest bits which need a closer look by Paul. Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Masami Hiramatsu Cc: Paolo Bonzini Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Steven Rostedt Link: http://lkml.kernel.org/r/20190726212124.210156346@linutronix.de Signed-off-by: Ingo Molnar

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

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.

linux/torture: Convert to SPDX license identifier

2019-02-09T16:46:31Z

Replace the license boiler plate with a SPDX license identifier. While in the area, update an email address. Signed-off-by: Paul E. McKenney [ paulmck: Update .h SPDX format per Joe Perches. ] Reviewed-by: Thomas Gleixner

rcutorture: Add grace period after CPU offline

2019-01-25T23:37:10Z

Beyond a certain point in the CPU-hotplug offline process, timers get stranded on the outgoing CPU, and won't fire until that CPU comes back online, which might well be never. This commit therefore adds a hook in torture_onoff_init() that is invoked from torture_offline(), which rcutorture uses to occasionally wait for a grace period. This should result in failures for RCU implementations that rely on stranded timers eventually firing in the absence of the CPU coming back online. Reported-by: Sebastian Andrzej Siewior Signed-off-by: Paul E. McKenney

rcutorture: Check GP completion at stutter end

2018-08-29T16:20:48Z

The rcu_torture_writer() function invokes stutter_wait() at the end of each writer pass, which occasionally blocks for an extended time period in order to ensure that RCU can handle intermittent loads. But part of handling a busy period is invoking all the callbacks before the end of the idle period induced by stutter_wait(). This commit therefore adds a return value to stutter_wait() indicating whether stutter_wait() actually waited. In addition, this commit causes rcu_torture_writer() to test this value and if set, checks that all the elements of the rcu_tortures[] array have been freed up. Signed-off-by: Paul E. McKenney

rcutorture: Use per-CPU random state for rcu_torture_timer()

2018-07-12T22:42:04Z

Currently, the rcu_torture_timer() function uses a single global torture_random_state structure protected by a single global lock. This conflicts to some extent with performance and scalability, but even more with the goal of consolidating read-side testing with rcu_torture_reader(). This commit therefore creates a per-CPU torture_random_state structure for use by rcu_torture_timer() and eliminates the lock. Signed-off-by: Paul E. McKenney [ paulmck: Make rcu_torture_timer_rand static, per 0day Test Robot report. ]

torture: Make online/offline messages appear only for verbose=2

2018-06-25T18:30:10Z

Some bugs reproduce quickly only at high CPU-hotplug rates, so the rcutorture TREE03 scenario now has only 200 milliseconds spacing between CPU-hotplug operations. At this rate, the torture-test pair of console messages per operation becomes a bit voluminous. This commit therefore converts the torture-test set of "verbose" kernel-boot arguments from bool to int, and prints the extra console messages only when verbose=2. The default is still verbose=1. Signed-off-by: Paul E. McKenney