kernel.git/kernel/rcu/rcuperf.c, branch linux-5.5.y

rcu: Remove unused variable rcu_perf_writer_state

2019-10-05T18:49:36Z

The variable rcu_perf_writer_state is declared and initialized, but is never actually referenced. Remove it to clean code. Signed-off-by: Ethan Hansen <1ethanhansen@gmail.com> [ paulmck: Also removed unused macros assigned to that variable. ] Signed-off-by: Paul E. McKenney

rcuperf: Make rcuperf kernel test more robust for !expedited mode

2019-08-01T21:30:22Z

It is possible that the rcuperf kernel test runs concurrently with init starting up. During this time, the system is running all grace periods as expedited. However, rcuperf can also be run for normal GP tests. Right now, it depends on a holdoff time before starting the test to ensure grace periods start later. This works fine with the default holdoff time however it is not robust in situations where init takes greater than the holdoff time to finish running. Or, as in my case: I modified the rcuperf test locally to also run a thread that did preempt disable/enable in a loop. This had the effect of slowing down init. The end result was that the "batches:" counter in rcuperf was 0 causing a division by 0 error in the results. This counter was 0 because only expedited GPs seem to happen, not normal ones which led to the rcu_state.gp_seq counter remaining constant across grace periods which unexpectedly happen to be expedited. The system was running expedited RCU all the time because rcu_unexpedited_gp() would not have run yet from init. In other words, the test would concurrently with init booting in expedited GP mode. To fix this properly, this commit waits until system_state is set to SYSTEM_RUNNING before starting the test. This change is made just before kernel_init() invokes rcu_end_inkernel_boot(), and this latter is what turns off boot-time expediting of RCU grace periods. Signed-off-by: Joel Fernandes (Google) Signed-off-by: Paul E. McKenney

rcuperf: Fix perf_type module-parameter description

2019-08-01T21:30:22Z

The rcu_bh rcuperf type was removed by commit 620d246065cd("rcuperf: Remove the "rcu_bh" and "sched" torture types"), but it lives on in the MODULE_PARM_DESC() of perf_type. This commit therefore changes that module-parameter description to substitute srcu for rcu_bh. Signed-off-by: Xiao Yang Signed-off-by: Paul E. McKenney

rcuperf: Fix cleanup path for invalid perf_type strings

2019-03-26T21:42:53Z

If the specified rcuperf.perf_type is not in the rcu_perf_init() function's perf_ops[] array, rcuperf prints some console messages and then invokes rcu_perf_cleanup() to set state so that a future torture test can run. However, rcu_perf_cleanup() also attempts to end the test that didn't actually start, and in doing so relies on the value of cur_ops, a value that is not particularly relevant in this case. This can result in confusing output or even follow-on failures due to attempts to use facilities that have not been properly initialized. This commit therefore sets the value of cur_ops to NULL in this case and inserts a check near the beginning of rcu_perf_cleanup(), thus avoiding relying on an irrelevant cur_ops value. 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.

rcu/rcuperf: Convert to SPDX license identifier

2019-02-09T16:43:35Z

Replace the license boiler plate with a SPDX license identifier. While in the area, update an email address. Signed-off-by: Paul E. McKenney Reviewed-by: Thomas Gleixner

rcuperf: Stop abusing IS_ENABLED()

2019-01-25T23:37:11Z

The ever-evolving IS_ENABLED() macro is intended for CONFIG_* Kconfig options, but rcuperf currently uses it for the decidedly non-CONFIG_* MODULE macro. In the spirit of not inviting trouble, this commit substitutes tried-and-true #ifdef. Reported-by: Ingo Molnar Signed-off-by: Paul E. McKenney Acked-by: Ingo Molnar

Merge branches 'doc.2018.08.30a', 'dynticks.2018.08.30b', 'srcu.2018.08.30b' and 'torture.2018.08.29a' into HEAD

2018-08-30T23:12:53Z

doc.2018.08.30a: Documentation updates dynticks.2018.08.30b: RCU flavor consolidation updates and cleanups srcu.2018.08.30b: SRCU updates torture.2018.08.29a: Torture-test updates

rcuperf: Remove the "rcu_bh" and "sched" torture types

2018-08-30T23:03:30Z

Now that the RCU-bh and RCU-sched update-side functions are simple wrappers around their RCU counterparts, there isn't a whole lot of point in testing them. This commit therefore removes the "rcu_bh" and "sched" torture types from rcuperf. Signed-off-by: Paul E. McKenney

rcuperf: Warn on bad perf type for built-in tests

2018-08-29T16:20:48Z

When running a built-in rcuperf test, specifying an invalid perf type results in what looks like a hard hang, with the error messages hidden by other boot-time output. This commit therefore executes a WARN_ON() in this case so that the splat appears just following the error messages. Signed-off-by: Paul E. McKenney