path: root/tools/testing/selftests/rcutorture/bin/jitter.sh (unfollow)
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2021-07-27torture: Use numeric taskset argument in jitter.shPaul E. McKenney1-7/+3
The jitter.sh script has some entertaining awk code to generate a hex mask from a randomly selected CPU number, which is handed to the "taskset" command. Except that this command has a "-c" parameter to take a comma/dash-separated list of CPU numbers. This commit therefore saves a few lines of awk by switching to a single-number CPU list. Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-03-08torture: Reverse jittering and duration parameters for jitter.shPaul E. McKenney1-3/+3
Remote rcutorture testing requires that jitter.sh continue to be invoked from the generated script for local runs, but that it instead be invoked on the remote system for distributed runs. This argues for common jitterstart and jitterstop scripts. But it would be good for jitterstart and jitterstop to control the name and location of the "jittering" file, while continuing to have the duration controlled by the caller of these new scripts. This commit therefore reverses the order of the jittering and duration parameters for jitter.sh, so that the jittering parameter precedes the duration parameter. Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-03-08torture: Use "jittering" file to control jitter.sh executionPaul E. McKenney1-4/+6
Currently, jitter.sh execution is controlled by a time limit and by the "kill" command. The former allowed jitter.sh to run uselessly past the end of a set of runs that panicked during boot, and the latter is vulnerable to PID reuse. This commit therefore introduces a "jittering" file in the date-stamp directory within "res" that must be present for the jitter.sh scripts to continue executing. The time limit is still in place in order to avoid disturbing runs featuring large trace dumps, but the removal of the "jittering" file handles the panic-during-boot scenario without relying on PIDs. Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-03-08torture: Make jitter.sh handle large systemsPaul E. McKenney1-4/+4
The current jitter.sh script expects cpumask bits to fit into whatever the awk interpreter uses for an integer, which clearly does not hold for even medium-sized systems these days. This means that on a large system, only the first 32 or 64 CPUs (depending) are subjected to jitter.sh CPU-time perturbations. This commit therefore computes a given CPU's cpumask using text manipulation rather than arithmetic shifts. Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2020-06-29torture: Add a stop-run capabilityPaul E. McKenney1-0/+6
When bisecting RCU issues, it is often the case that the first error in an unsuccessful run will happen quickly, but that a successful run must go on for some time in order to obtain a sufficiently low false-negative error rate. In many cases, a bisection requires multiple concurrent runs, in which case the first failure in any run indicates failure, pure and simple. In such cases, it would speed things up greatly if the first failure terminated all runs. This commit therefore adds scripting that checks for a file named "STOP" in the top-level results directory, terminating the run when it appears. Note that in-progress builds will continue until completion, but future builds and all runs will be cut short. Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2019-12-09torture: Handle jitter for CPUs that cannot be offlinedPaul E. McKenney1-6/+20
Currently, jitter.sh assumes that the underlying hypervisor will be configured with all CPUs hotpluggable, with the possible exception of CPU 0. However, there are installations where the hypervisor prohibits offlining, which breaks jitter.sh. This commit therefore lists the CPUs that cannot be offlined up front, and checks for the case where no CPU can be offlined in the loop. Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2019-12-09torture: Use gawk instead of awk for systime() functionPaul E. McKenney1-2/+2
In many environments, gawk provides systime(), but awk doesn't. This commit therefore changes awk scripts using systime() to instead be gawk scripts. Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2019-05-28rcutorture: Add cpu0 to the set of CPUs to add jitterJoel Fernandes (Google)1-2/+6
jitter.sh currently does not add CPU0 to the list of CPUs for adding of jitter. Let us add it to this list even when it is not hot-pluggable. Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
2019-05-28rcutorture: Select from only online CPUsJoel Fernandes (Google)1-2/+3
The rcutorture jitter.sh script selects a random CPU but does not check if it is offline or online. This leads to taskset errors many times. On my machine, hyper threading is disabled so half the cores are offline causing taskset errors a lot of times. Let us fix this by checking from only the online CPUs on the system. Cc: rcu@vger.kernel.org Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
2019-03-26tools/.../rcutorture: Convert to SPDX license identifierPaul E. McKenney1-15/+2
Replace the license boiler plate with a SPDX license identifier. While in the area, update an email address and add copyright notices. Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
2016-04-21rcutorture: Add OS-jitter capabilityPaul E. McKenney1-0/+90
This commit adds a --jitter OS-jitter capability to expose bugs based on no-delay assumptions. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>