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* refscale: Add missing '\n' to flush messageLi Zhijian2021-12-071-4/+7
| | | | | | | | Add '\n' to macros to flush message for each call. Acked-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Li Zhijian <zhijianx.li@intel.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
* refscale: Always log the error messageLi Zhijian2021-12-071-4/+3
| | | | | | | | | | | An OOM is a serious error that should be logged even in non-verbose runs. This commit therefore adds an unconditional SCALEOUT_ERRSTRING() macro and uses it instead of VERBOSE_SCALEOUT_ERRSTRING() when reporting an OOM. [ paulmck: Drop do-while from SCALEOUT_ERRSTRING() due to only single statement. ] Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
* refscale: Prevent buffer to pr_alert() being too longLi Zhijian2021-11-301-10/+13
| | | | | | | | | | | | 0Day/LKP observed that the refscale results fail to complete when larger values of nrun (such as 300) are specified. The problem is that printk() can accept at most a 1024-byte buffer. This commit therefore prints the buffer whenever its length exceeds 800 bytes. CC: Philip Li <philip.li@intel.com> Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
* refscale: Simplify the errexit checkpointLi Zhijian2021-11-301-13/+6
| | | | | | | | | There is only the one OOM error case in main_func(), so this commit eliminates the errexit local variable in favor of a branch to cleanup code. Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
* refscale: Warn on individual ref_scale_init() error conditionsPaul E. McKenney2021-09-131-3/+3
| | | | | | | | | | | When running refscale as a module, any ref_scale_init() issues will be reflected in the error code from modprobe or insmod, as the case may be. However, these error codes are not available when running refscale built-in, for example, when using the kvm.sh script. This commit therefore adds WARN_ON_ONCE() to allow distinguishing ref_scale_init() errors when running refscale built-in. Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
* refscale: Add measurement of clock readoutPaul E. McKenney2021-07-271-1/+35
| | | | | | | | | This commit adds a "clock" type to refscale, which checks the performance of ktime_get_real_fast_ns(). Use the "clocksource=" kernel boot parameter to select the underlying clock source. [ paulmck: Work around compiler false positive per kernel test robot. ] Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
* refscale: Avoid false-positive warnings in ref_scale_reader()Paul E. McKenney2021-07-061-3/+3
| | | | | | | | | | | | | | | | | | | | If the call to set_cpus_allowed_ptr() in ref_scale_reader() fails, a later WARN_ONCE() complains. But with the advent of 570a752b7a9b ("lib/smp_processor_id: Use is_percpu_thread() instead of nr_cpus_allowed"), this complaint can be drowned out by complaints from smp_processor_id(). The rationale for this change is that refscale's kthreads are not marked with PF_NO_SETAFFINITY, which means that a system administrator could change affinity at any time. However, refscale is a performance/stress test, and the system administrator might well have a valid test-the-test reason for changing affinity. This commit therefore changes to raw_smp_processor_id() in order to avoid the noise, and also adds a WARN_ON_ONCE() to the call to set_cpus_allowed_ptr() in order to directly detect immediate failure. There is no WARN_ON_ONCE() within the test loop, allowing human-reflex-based affinity resetting, if desired. Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
* refscale: Add acqrel, lock, and lock-irqPaul E. McKenney2021-05-101-2/+107
| | | | | | | | | | This commit adds scale_type of acqrel, lock, and lock-irq to test acquisition and release. Note that the refscale.nreaders=1 module parameter is required if you wish to test uncontended locking. In contrast, acqrel uses a per-CPU variable, so should be just fine with large values of the refscale.nreaders=1 module parameter. Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
* torture: Make refscale throttle high-rate printk()sPaul E. McKenney2021-01-061-1/+3
| | | | | | | This commit adds a short delay for verbose_batched-throttled printk()s to further decrease console flooding. Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
* refscale: Allow summarization of verbose outputPaul E. McKenney2021-01-061-5/+16
| | | | | | | | | The refscale test prints enough per-kthread console output to provoke RCU CPU stall warnings on large systems. This commit therefore allows this output to be summarized. For example, the refscale.verbose_batched=32 boot parameter would causes only every 32nd line of output to be logged. Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
* refscale: Prevent hangs for invalid argumentsPaul E. McKenney2020-11-061-1/+4
| | | | | | | | | | | | If an refscale torture-test run is given a bad kvm.sh argument, the test will complain to the console, which is good. What is bad is that from the user's perspective, it will just hang for the time specified by the --duration argument. This commit therefore forces an immediate kernel shutdown if a ref_scale_init()-time error occurs, thus avoiding the appearance of a hang. It also forces a console splat in this case to clearly indicate the presence of an error. Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
* refscale: Bounds-check module parametersPaul E. McKenney2020-11-021-0/+6
| | | | | | | | | | | | | | | | The default value for refscale.nreaders is -1, which results in the code setting the value to three-quarters of the number of CPUs. On single-CPU systems, this results in three-quarters of the value one, which the C language's integer arithmetic rounds to zero. This in turn results in a divide-by-zero error. This commit therefore adds bounds checking to the refscale module parameters, so that if they are less than one, they are set to the value one. Reported-by: kernel test robot <lkp@intel.com> Tested-by "Chen, Rong A" <rong.a.chen@intel.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
* refperf: Avoid null pointer dereference when buf fails to allocateColin Ian King2020-08-241-3/+5
| | | | | | | | | | | Currently in the unlikely event that buf fails to be allocated it is dereferenced a few times. Use the errexit flag to determine if buf should be written to to avoid the null pointer dereferences. Addresses-Coverity: ("Dereference after null check") Fixes: f518f154ecef ("refperf: Dynamically allocate experiment-summary output buffer") Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
* refperf: Rename refperf.c to refscale.c and change internal namesPaul E. McKenney2020-06-291-0/+717
This commit further avoids conflation of refperf with the kernel's perf feature by renaming kernel/rcu/refperf.c to kernel/rcu/refscale.c, and also by similarly renaming the functions and variables inside this file. This has the side effect of changing the names of the kernel boot parameters, so kernel-parameters.txt and ver_functions.sh are also updated. The rcutorture --torture type remains refperf, and this will be addressed in a separate commit. Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
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